At least CP2102 requires the XON/XOFF limits to be initialised in order
for software input flow control (IXOFF) to work. Specifically, XOFF is
never sent if the XOFF limit is left at its default value of zero.

Set the limits so that input is throttled when the FIFO free level drops
below 128 bytes and restarted when the FIFO fill level drops below 128
bytes.

Note that the threshold values have been chosen so that they can be used
also with CP2105 which has the smallest FIFO of the currently supported
device types (288 byte for the SCI port). If needed the limits can be
made device specific later.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

When data is transmitted between two serial ports, the phenomenon of
data loss often occurs. The two kinds of flow control commonly used in
serial communication are hardware flow control and software flow
control.

In serial communication, If you only use RX/TX/GND Pins, you can't do
hardware flow. So we often used software flow control and prevent data
loss. The user sets the software flow control through the application
program, and the application program sets the software flow control mode
for the serial port chip through the driver.

For the cp210 serial port chip, its driver lacks the software flow
control setting code, so the user cannot set the software flow control
function through the application program. This adds the missing software
flow control.
Signed-off-by: NWang Sheng Long <shenglong.wang.ext@siemens.com>
Link: https://lore.kernel.org/r/20210104094502.3942-1-china_shenglong@163.com
[ johan: rework properly on top of recent termios changes ]
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The latest chip family (HXN) apparently does not support setting the
line speed using divisors and instead needs to use the direct encoding
scheme for all rates.

This specifically enables 50, 110, 134, 200 bps and other rates not
supported by the original chip type.

Fixes: ebd09f1c ("USB: serial: pl2303: add support for PL2303HXN")
Cc: stable@vger.kernel.org      # 5.5
Cc: Charles Yeh <charlesyeh522@gmail.com>
Signed-off-by: NJohan Hovold <johan@kernel.org>

clang static analysis reports this problem

mos7720.c:352:2: warning: Undefined or garbage value returned to caller
        return d;
        ^~~~~~~~

In the parport_mos7715_read_data()'s call to read_mos_reg(), 'd' is
only set after the alloc block.

	buf = kmalloc(1, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

Although the problem is reported in parport_most7715_read_data(),
none of the callee's of read_mos_reg() check the return status.

Make sure to clear the return-value buffer also on allocation failures.

Fixes: 0d130367 ("USB: serial: mos7720: fix control-message error handling")
Signed-off-by: NTom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20210111220904.1035957-1-trix@redhat.com
[ johan: only clear the buffer on errors, amend commit message ]
Signed-off-by: NJohan Hovold <johan@kernel.org>

Stack-allocated buffers cannot be used for DMA (on all architectures) so
allocate the flush command buffer using kmalloc().

Fixes: 60a8fc01 ("USB: add iuu_phoenix driver")
Cc: stable <stable@vger.kernel.org>     # 2.6.25
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add a device-id entry for the LongSung M5710 module.

T:  Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  2 Spd=480  MxCh= 0
D:  Ver= 2.00 Cls=ef(misc ) Sub=02 Prot=01 MxPS=64 #Cfgs=  1
P:  Vendor=2df3 ProdID=9d03 Rev= 1.00
S:  Manufacturer=Marvell
S:  Product=Mobile Composite Device Bus
S:  SerialNumber=<snip>
C:* #Ifs= 5 Cfg#= 1 Atr=c0 MxPwr=500mA
A:  FirstIf#= 0 IfCount= 2 Cls=e0(wlcon) Sub=01 Prot=03
I:* If#= 0 Alt= 0 #EPs= 1 Cls=e0(wlcon) Sub=01 Prot=03 Driver=rndis_host
E:  Ad=87(I) Atr=03(Int.) MxPS=  64 Ivl=4096ms
I:* If#= 1 Alt= 0 #EPs= 2 Cls=0a(data ) Sub=00 Prot=00 Driver=rndis_host
E:  Ad=83(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=0c(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 2 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
E:  Ad=82(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=0b(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 4 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
E:  Ad=89(I) Atr=03(Int.) MxPS=  64 Ivl=4096ms
E:  Ad=86(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=0f(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 5 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
E:  Ad=88(I) Atr=03(Int.) MxPS=  64 Ivl=4096ms
E:  Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=0a(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
Signed-off-by: NDaniel Palmer <daniel@0x0f.com>
https://lore.kernel.org/r/20201227031716.1343300-1-daniel@0x0f.com
[ johan: drop id defines, only bind to vendor class ]
Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>

New modem using ff/ff/30 for QCDM, ff/00/00 for  AT and NMEA,
and ff/ff/ff for RMNET/QMI.

T: Bus=02 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=5000 MxCh= 0
D: Ver= 3.20 Cls=ef(misc ) Sub=02 Prot=01 MxPS= 9 #Cfgs= 1
P: Vendor=2c7c ProdID=0620 Rev= 4.09
S: Manufacturer=Quectel
S: Product=EM160R-GL
S: SerialNumber=e31cedc1
C:* #Ifs= 5 Cfg#= 1 Atr=a0 MxPwr=896mA
I:* If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=30 Driver=(none)
E: Ad=81(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E: Ad=01(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
I:* If#= 1 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)
E: Ad=83(I) Atr=03(Int.) MxPS= 10 Ivl=32ms
E: Ad=82(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E: Ad=02(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
I:* If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)
E: Ad=85(I) Atr=03(Int.) MxPS= 10 Ivl=32ms
E: Ad=84(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E: Ad=03(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
I:* If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)
E: Ad=87(I) Atr=03(Int.) MxPS= 10 Ivl=32ms
E: Ad=86(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E: Ad=04(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms
I:* If#= 4 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
E: Ad=88(I) Atr=03(Int.) MxPS= 8 Ivl=32ms
E: Ad=8e(I) Atr=02(Bulk) MxPS=1024 Ivl=0ms
E: Ad=0f(O) Atr=02(Bulk) MxPS=1024 Ivl=0ms

Cc: stable@vger.kernel.org
Signed-off-by: NBjørn Mork <bjorn@mork.no>
[ johan: add model comment ]
Signed-off-by: NJohan Hovold <johan@kernel.org>

The validity of the ftdi CBUS GPIO is pretty hidden so far,
and finding out *why* some GPIOs don't work is sometimes
hard to identify. So let's help the user by displaying the
map of the CBUS pins that are valid for a GPIO.
Suggested-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201204164739.781812-4-maz@kernel.orgReviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
[johan: demote to KERN_DEBUG, rephrase messages, drop ftx-prog warning]
Signed-off-by: NJohan Hovold <johan@kernel.org>

Now that gpiolib can track the validity of GPIO pins, there is no need
to check whether the line is valid in request().
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201204164739.781812-5-maz@kernel.orgReviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
[johan: amend commit message]
Signed-off-by: NJohan Hovold <johan@kernel.org>

Since it is pretty common for only some of the CBUS lines to be
valid as GPIO lines, let's report such validity to the rest of
the kernel.
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20201204164739.781812-3-maz@kernel.orgReviewed-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add an interface-number sanity check before testing the device flags to
avoid relying on undefined behaviour when left shifting in case a device
uses an interface number greater than or equal to BITS_PER_LONG (i.e. 64
or 32).

Reported-by: syzbot+8881b478dad0a7971f79@syzkaller.appspotmail.com
Fixes: c3a65808 ("USB: serial: option: reimplement interface masking")
Cc: stable@vger.kernel.org
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Clean up dtr_rts() by renaming the port parameter and adding missing
whitespace.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add a helper function to be used to configure flow control.

The flow-control code was the last caller that relied on the
memset-on-failure behaviour of cp210x_read_reg_block(), which we can now
drop in favour of bailing out on errors when retrieving the flow-control
settings.

This should also simplify adding support for software flow control.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Drop some unnecessary flow-control debugging.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Unlike other drivers cp210x have been retrieving the current terminal
settings from the device on open and reflecting those in termios.

Due to how set_termios() used to be implemented, this saved a few
control requests on open but has instead caused problems like broken
flow control and has required adding workarounds for swapped
line-control in cp2108 and line-speed initialisation on cp2104.

This unusual implementation also complicates adding new features for no
good reason.

Rip out the corresponding code and the above mentioned workarounds and
instead initialise the terminal settings unconditionally on open.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Update the line-control settings in one request unconditionally instead
of setting the word-length, parity and stop-bit settings separately.

This avoids multiple requests when several settings are changed even if
this scheme could potentially also be used to detect unsupported device
settings. Since all device types but CP2101 appears to support all
settings, let's handle that one specifically and also report back the
unsupported settings properly through termios by clearing the
corresponding bits.

Also drop the related unnecessary debug printks.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Return early from set_termios() in case no relevant terminal settings
have changed.

This avoids testing each parameter in turn and specifically allows the
line-control handling to be cleaned up further.
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix memory leak of control-message transfer buffer on successful open().

Fixes: 6774d5f5 ("USB: serial: kl5kusb105: fix open error path")
Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>

Keep the device-id entries sorted to make it easier to add new ones in
the right spot.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add PID for CH340 that's found on a ch341 based Programmer made by keeyees.
The specific device that contains the serial converter is described
here: http://www.keeyees.com/a/Products/ej/36.html

The driver works flawlessly as soon as the new PID (0x5512) is added to
it.
Signed-off-by: NJan-Niklas Burfeind <kernel@aiyionpri.me>
Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>

This is a partial revert of commit 2bb70f0a ("USB: serial:
option: support dynamic Quectel USB compositions")

The Quectel BG96 is different from most other modern Quectel modems,
having serial functions with 3 endpoints using ff/ff/ff and ff/fe/ff
class/subclass/protocol. Including it in the change to accommodate
dynamic function mapping was incorrect.

Revert to interface number matching for the BG96, assuming static
layout of the RMNET function on interface 4. This restores support
for the serial functions on interfaces 2 and 3.

Full lsusb output for the BG96:

Bus 002 Device 003: ID 2c7c:0296
Device Descriptor:
 bLength                18
 bDescriptorType         1
 bcdUSB               2.00
 bDeviceClass            0 (Defined at Interface level)
 bDeviceSubClass         0
 bDeviceProtocol         0
 bMaxPacketSize0        64
 idVendor           0x2c7c
 idProduct          0x0296
 bcdDevice            0.00
 iManufacturer           3 Qualcomm, Incorporated
 iProduct                2 Qualcomm CDMA Technologies MSM
 iSerial                 4 d1098243
 bNumConfigurations      1
 Configuration Descriptor:
   bLength                 9
   bDescriptorType         2
   wTotalLength          145
   bNumInterfaces          5
   bConfigurationValue     1
   iConfiguration          1 Qualcomm Configuration
   bmAttributes         0xe0
     Self Powered
     Remote Wakeup
   MaxPower              500mA
   Interface Descriptor:
     bLength                 9
     bDescriptorType         4
     bInterfaceNumber        0
     bAlternateSetting       0
     bNumEndpoints           2
     bInterfaceClass       255 Vendor Specific Class
     bInterfaceSubClass    255 Vendor Specific Subclass
     bInterfaceProtocol    255 Vendor Specific Protocol
     iInterface              0
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x81  EP 1 IN
       bmAttributes            2
         Transfer Type            Bulk
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0200  1x 512 bytes
       bInterval               0
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x01  EP 1 OUT
       bmAttributes            2
         Transfer Type            Bulk
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0200  1x 512 bytes
       bInterval               0
   Interface Descriptor:
     bLength                 9
     bDescriptorType         4
     bInterfaceNumber        1
     bAlternateSetting       0
     bNumEndpoints           2
     bInterfaceClass       255 Vendor Specific Class
     bInterfaceSubClass    255 Vendor Specific Subclass
     bInterfaceProtocol    255 Vendor Specific Protocol
     iInterface              0
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x82  EP 2 IN
       bmAttributes            2
         Transfer Type            Bulk
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0200  1x 512 bytes
       bInterval               0
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x02  EP 2 OUT
       bmAttributes            2
         Transfer Type            Bulk
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0200  1x 512 bytes
       bInterval               0
   Interface Descriptor:
     bLength                 9
     bDescriptorType         4
     bInterfaceNumber        2
     bAlternateSetting       0
     bNumEndpoints           3
     bInterfaceClass       255 Vendor Specific Class
     bInterfaceSubClass    255 Vendor Specific Subclass
     bInterfaceProtocol    255 Vendor Specific Protocol
     iInterface              0
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x83  EP 3 IN
       bmAttributes            3
         Transfer Type            Interrupt
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0040  1x 64 bytes
       bInterval               5
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x84  EP 4 IN
       bmAttributes            2
         Transfer Type            Bulk
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0200  1x 512 bytes
       bInterval               0
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x03  EP 3 OUT
       bmAttributes            2
         Transfer Type            Bulk
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0200  1x 512 bytes
       bInterval               0
   Interface Descriptor:
     bLength                 9
     bDescriptorType         4
     bInterfaceNumber        3
     bAlternateSetting       0
     bNumEndpoints           3
     bInterfaceClass       255 Vendor Specific Class
     bInterfaceSubClass    254
     bInterfaceProtocol    255
     iInterface              0
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x85  EP 5 IN
       bmAttributes            3
         Transfer Type            Interrupt
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0040  1x 64 bytes
       bInterval               5
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x86  EP 6 IN
       bmAttributes            2
         Transfer Type            Bulk
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0200  1x 512 bytes
       bInterval               0
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x04  EP 4 OUT
       bmAttributes            2
         Transfer Type            Bulk
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0200  1x 512 bytes
       bInterval               0
   Interface Descriptor:
     bLength                 9
     bDescriptorType         4
     bInterfaceNumber        4
     bAlternateSetting       0
     bNumEndpoints           3
     bInterfaceClass       255 Vendor Specific Class
     bInterfaceSubClass    255 Vendor Specific Subclass
     bInterfaceProtocol    255 Vendor Specific Protocol
     iInterface              0
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x87  EP 7 IN
       bmAttributes            3
         Transfer Type            Interrupt
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0040  1x 64 bytes
       bInterval               5
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x88  EP 8 IN
       bmAttributes            2
         Transfer Type            Bulk
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0200  1x 512 bytes
       bInterval               0
     Endpoint Descriptor:
       bLength                 7
       bDescriptorType         5
       bEndpointAddress     0x05  EP 5 OUT
       bmAttributes            2
         Transfer Type            Bulk
         Synch Type               None
         Usage Type               Data
       wMaxPacketSize     0x0200  1x 512 bytes
       bInterval               0
Device Qualifier (for other device speed):
 bLength                10
 bDescriptorType         6
 bcdUSB               2.00
 bDeviceClass            0 (Defined at Interface level)
 bDeviceSubClass         0
 bDeviceProtocol         0
 bMaxPacketSize0        64
 bNumConfigurations      1
Device Status:     0x0000
 (Bus Powered)

Cc: Sebastian Sjoholm <sebastian.sjoholm@gmail.com>
Fixes: 2bb70f0a ("USB: serial: option: support dynamic Quectel USB compositions")
Signed-off-by: NBjørn Mork <bjorn@mork.no>
Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>

There is a single option port in this modem, and it is used as debug port.

lsusb -v for this device:

Bus 001 Device 002: ID 1e2d:006c
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass          239 Miscellaneous Device
  bDeviceSubClass         2 ?
  bDeviceProtocol         1 Interface Association
  bMaxPacketSize0        64
  idVendor           0x1e2d
  idProduct          0x006c
  bcdDevice            0.00
  iManufacturer           4
  iProduct                3
  iSerial                 5
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength          243
    bNumInterfaces          7
    bConfigurationValue     1
    iConfiguration          2
    bmAttributes         0xe0
      Self Powered
      Remote Wakeup
    MaxPower              500mA
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass       255 Vendor Specific Class
      bInterfaceSubClass    255 Vendor Specific Subclass
      bInterfaceProtocol    255 Vendor Specific Protocol
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x01  EP 1 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
    Interface Association:
      bLength                 8
      bDescriptorType        11
      bFirstInterface         1
      bInterfaceCount         2
      bFunctionClass          2 Communications
      bFunctionSubClass       2 Abstract (modem)
      bFunctionProtocol       1 AT-commands (v.25ter)
      iFunction               0
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        1
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         2 Communications
      bInterfaceSubClass      2 Abstract (modem)
      bInterfaceProtocol      1 AT-commands (v.25ter)
      iInterface              0
      CDC Header:
        bcdCDC               1.10
      CDC ACM:
        bmCapabilities       0x02
          line coding and serial state
      CDC Call Management:
        bmCapabilities       0x03
          call management
          use DataInterface
        bDataInterface          2
      CDC Union:
        bMasterInterface        1
        bSlaveInterface         2
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               5
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        2
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass        10 CDC Data
      bInterfaceSubClass      0 Unused
      bInterfaceProtocol      0
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x83  EP 3 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x02  EP 2 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
    Interface Association:
      bLength                 8
      bDescriptorType        11
      bFirstInterface         3
      bInterfaceCount         2
      bFunctionClass          2 Communications
      bFunctionSubClass       2 Abstract (modem)
      bFunctionProtocol       1 AT-commands (v.25ter)
      iFunction               0
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        3
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         2 Communications
      bInterfaceSubClass      2 Abstract (modem)
      bInterfaceProtocol      1 AT-commands (v.25ter)
      iInterface              0
      CDC Header:
        bcdCDC               1.10
      CDC ACM:
        bmCapabilities       0x02
          line coding and serial state
      CDC Call Management:
        bmCapabilities       0x03
          call management
          use DataInterface
        bDataInterface          4
      CDC Union:
        bMasterInterface        3
        bSlaveInterface         4
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x84  EP 4 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               5
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        4
      bAlternateSetting       0
      bNumEndpoints           2
      bInterfaceClass        10 CDC Data
      bInterfaceSubClass      0 Unused
      bInterfaceProtocol      0
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x85  EP 5 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x03  EP 3 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
    Interface Association:
      bLength                 8
      bDescriptorType        11
      bFirstInterface         5
      bInterfaceCount         2
      bFunctionClass          2 Communications
      bFunctionSubClass       2 Abstract (modem)
      bFunctionProtocol       1 AT-commands (v.25ter)
      iFunction               0
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        5
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         2 Communications
      bInterfaceSubClass      6 Ethernet Networking
      bInterfaceProtocol      0
      iInterface              0
      CDC Header:
        bcdCDC               1.10
      CDC Ethernet:
        iMacAddress                      1 (??)
        bmEthernetStatistics    0x00000000
        wMaxSegmentSize              16384
        wNumberMCFilters            0x0001
        bNumberPowerFilters              0
      CDC Union:
        bMasterInterface        5
        bSlaveInterface         6
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x86  EP 6 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               5
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        6
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass        10 CDC Data
      bInterfaceSubClass      0 Unused
      bInterfaceProtocol      0
      iInterface              0
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber        6
      bAlternateSetting       1
      bNumEndpoints           2
      bInterfaceClass        10 CDC Data
      bInterfaceSubClass      0 Unused
      bInterfaceProtocol      0
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x87  EP 7 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x04  EP 4 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
Signed-off-by: NGiacinto Cifelli <gciofono@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>

Update the USB serial option driver support for the Fibocom NL668 Cat.4
LTE modules as there are actually several different variants.
Got clarifications from Fibocom, there are distinct products:
- VID:PID 1508:1001, NL668 for IOT (no MBIM interface)
- VID:PID 2cb7:01a0, NL668-AM and NL652-EU are laptop M.2 cards (with
  MBIM interfaces for Windows/Linux/Chrome OS), respectively for Americas
  and Europe.

usb-devices output for the laptop M.2 cards:
T:  Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#=  4 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=ef(misc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=2cb7 ProdID=01a0 Rev=03.18
S:  Manufacturer=Fibocom Wireless Inc.
S:  Product=Fibocom NL652-EU Modem
S:  SerialNumber=0123456789ABCDEF
C:  #Ifs= 5 Cfg#= 1 Atr=a0 MxPwr=500mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=02(commc) Sub=0e Prot=00 Driver=cdc_mbim
I:  If#= 1 Alt= 1 #EPs= 2 Cls=0a(data ) Sub=00 Prot=02 Driver=cdc_mbim
I:  If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)
I:  If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)
I:  If#= 4 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
Signed-off-by: NVincent Palatin <vpalatin@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>

The parallel port restore operation currently defers writes
to a tasklet, if it sees a locked disconnect mutex. The
driver goes to a lot of trouble to ensure writes happen
in a non-blocking context, but things can be greatly
simplified if it's done in regular process context and
this is not a system performance critical path. As such,
instead of doing the state restore writes in softirq context,
use a workqueue and just do regular synchronous writes.

In addition to the cleanup, this also imposes less on the
overall system as tasklets have been deprecated because
of it's softirq implications, potentially blocking a higher
priority task from running.
Signed-off-by: NDavidlohr Bueso <dbueso@suse.de>
Link: https://lore.kernel.org/r/20201120045300.28804-1-dave@stgolabs.net
[johan: amend commit message ("softirq context")]
Signed-off-by: NJohan Hovold <johan@kernel.org>

The parallel-port restore operations is called when a driver claims the
port and is supposed to restore the provided state (e.g. saved when
releasing the port).

Fixes: b69578df ("USB: usbserial: mos7720: add support for parallel port on moschip 7715")
Cc: stable <stable@vger.kernel.org>     # 2.6.35
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add the following Telit FN980 composition:

0x1055: tty, adb, tty, tty, tty, tty
Signed-off-by: NDaniele Palmas <dnlplm@gmail.com>
Link: https://lore.kernel.org/r/20201103124425.12940-1-dnlplm@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add following Telit LE910Cx compositions:

0x1203: rndis, tty, adb, tty, tty, tty, tty
0x1230: tty, adb, rmnet, audio, tty, tty, tty, tty
0x1231: rndis, tty, adb, audio, tty, tty, tty, tty
Signed-off-by: NDaniele Palmas <dnlplm@gmail.com>
Link: https://lore.kernel.org/r/20201031225458.10512-1-dnlplm@gmail.com
[ johan: add comments after entries ]
Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>

The digi_acceleport driver is the only driver still using the port
write wake queue so move it to that driver's port data.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The driver must not call tty_wakeup() while holding its private lock as
line disciplines are allowed to call back into write() from
write_wakeup(), leading to a deadlock.

Also remove the unneeded work struct that was used to defer wakeup in
order to work around a possible race in ancient times (see comment about
n_tty write_chan() in commit 14b54e39 ("USB: serial: remove
changelogs and old todo entries")).

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The write-URB busy flag was being cleared before the completion handler
was done with the URB, something which could lead to corrupt transfers
due to a racing write request if the URB is resubmitted.

Fixes: 507ca9bc ("[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.")
Cc: stable <stable@vger.kernel.org>     # 2.6.13
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Drop the redundant struct usb_serial pointer from the driver port data.
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Use the BIT() macro instead of open coding.
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Clean up comment style, remove some stale or redundant comments and drop
superfluous white space.
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Drop the separate Kconfig symbol for Xircom / Entrega and always include
support in the keyspan_pda driver.

Note that all configs that enabled CONFIG_USB_SERIAL_XIRCOM also enable
CONFIG_USB_SERIAL_KEYSPAN_PDA.
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Use the port write fifo and generic chars_and_buffer and write_room
implementations when writing. This not only allows for more efficient
transfers, but more importantly fixes the remaining issues related to
the conservative write_room() implementation which could prevent the
line discipline from making forward progress (e.g. waiting for n > 1
bytes of space to become available).

Note that this also allows using the driver for the system console
without dropping data when the write URB is busy (including when adding
carriage return on line feed).
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Increase the transmitter threshold so that writing isn't resumed until
128 bytes are available in the device buffer thereby allowing for larger
and more efficient transfers.
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix stalled writes by checking the available buffer space after
requesting an unthrottle notification in case the device buffer is
already empty so that no notification is ever sent (e.g. when doing
single character writes).

This also means we can drop the room query from write() which was
conditioned on in_interrupt() and prevented writing using this driver
from atomic contexts (e.g. PPP).
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add helper to retrieve the available device transfer-buffer space.
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The driver did not update its view of the available device buffer space
until write() was called in task context. This meant that write_room()
would return 0 even after the device had sent a write-unthrottle
notification, something which could lead to blocked writers not being
woken up (e.g. when using OPOST).

Note that we must also request an unthrottle notification is case a
write() request fills the device buffer exactly.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The driver's transmit-unthrottle work was never flushed on disconnect,
something which could lead to the driver port data being freed while the
unthrottle work is still scheduled.

Fix this by cancelling the unthrottle work when shutting down the port.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Acked-by: NSebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>