The port data is not exported to user space so use the in-kernel u8
type.

Link: https://lore.kernel.org/r/20200713105517.27796-6-johan@kernel.orgReviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Drop unnecessary packed attributes from structs without padding.

Link: https://lore.kernel.org/r/20200713105517.27796-5-johan@kernel.orgReviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Enable TIOCGICOUNT to allow reading out the (unused) interrupt counters
and error statistics.

Note that modem-status events are currently left unimplemented as they
appear to be buffered on at least CP2102 and therefore cannot be used to
implement TIOCMIWAIT.

Link: https://lore.kernel.org/r/20200713105517.27796-4-johan@kernel.orgReviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add support for line-status events that specifically can be used to
detect and report parity errors.

Enable the device's event-insertion mode whenever input-parity checking
is requested. This will insert line and modem status events into the
data stream.

Note that modem-status changes appear to be buffered until a character
is received (at least on CP2102) and support is therefore left
unimplemented.

On at least one type of these chips (CP2102), line breaks are not
reported as expected either (regardless of whether SERIAL_BREAK_CHAR is
set) so do not enable event-mode when !IGNBRK is requested for now.

Link: https://lore.kernel.org/r/20200713105517.27796-3-johan@kernel.orgReviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Try to disable the serial interface in the unlikely event that generic
open() fails.

Link: https://lore.kernel.org/r/20200713105517.27796-2-johan@kernel.orgReviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Drop redundant URB transfer-buffer casts.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add inline sysrq break-handler dummy to allow the compiler to eliminate
further code when either console or sysrq support isn't enabled and to
clearly mark the two sysrq functions as belonging together.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Inline the dummy sysrq character handling when either console support or
magic-sysrq support isn't enabled to allow the compiler to eliminate
unused code.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Do not set the sysrq timestamp unless CONFIG_MAGIC_SYSRQ is enabled to
avoid unnecessary per-character processing for consoles.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Only set the sysrq timestamp for console ports to avoid having every
driver also check the console flag when processing incoming data.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Only the last NUL in a packet should be flagged as a break character,
for example, to avoid dropping unrelated characters when IGNBRK is set.

Also make sysrq work by consuming the break character instead of having
it immediately cancel the sysrq request, and by not processing it
prematurely to avoid triggering a sysrq based on an unrelated character
received in the same packet (which was received *before* the break).

Note that the break flag can be left set also for a packet received
immediately following a break and that and an ending NUL in such a
packet will continue to be reported as a break as there's no good way to
tell it apart from an actual break.

Tested on FT232R and FT232H.

Fixes: 72fda3ca ("USB: serial: ftd_sio: implement sysrq handling on break")
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Clean up receive processing by dropping the character pointer and
keeping the length argument unchanged throughout the function.

Also make it more apparent that sysrq processing can consume a
characters by adding an explicit continue.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Use an unsigned type for the process-packet buffer argument and give it
a more apt name.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-throughSigned-off-by: NGustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

On devices which do not support break signalling a break condition is
simulated by sending a NUL byte at the lowest possible speed. The break
condition will be 9 bit periods long (start bit and eight data bits),
but the transmission itself also includes the stop bit.

Add the missing safety margin of one bit which is intended to account
for timing differences, and fix up the corresponding comment.
Signed-off-by: NMichael Hanselmann <public@hansmi.ch>
Link: https://lore.kernel.org/r/9909b288-294d-16b9-9f14-51eb79c63b6c@msgid.hansmi.ch
[ johan: amend commit message ]
Signed-off-by: NJohan Hovold <johan@kernel.org>

CP210x hardware disables auto-RTS but leaves auto-CTS when in hardware
flow control mode and UART on cp210x hardware is disabled. When
re-opening the port, if auto-CTS is enabled on the cp210x, then auto-RTS
must be re-enabled in the driver.
Signed-off-by: NBrant Merryman <brant.merryman@silabs.com>
Co-developed-by: NPhu Luu <phu.luu@silabs.com>
Signed-off-by: NPhu Luu <phu.luu@silabs.com>
Link: https://lore.kernel.org/r/ECCF8E73-91F3-4080-BE17-1714BC8818FB@silabs.com
[ johan: fix up tags and problem description ]
Fixes: 39a66b8d ("[PATCH] USB: CP2101 Add support for flow control")
Cc: stable <stable@vger.kernel.org>     # 2.6.12
Signed-off-by: NJohan Hovold <johan@kernel.org>

Assign the .throttle and .unthrottle functions to be generic function
in the driver structure to prevent data loss that can otherwise occur
if the host does not enable USB throttling.
Signed-off-by: NBrant Merryman <brant.merryman@silabs.com>
Co-developed-by: NPhu Luu <phu.luu@silabs.com>
Signed-off-by: NPhu Luu <phu.luu@silabs.com>
Link: https://lore.kernel.org/r/57401AF3-9961-461F-95E1-F8AFC2105F5E@silabs.com
[ johan: fix up tags ]
Fixes: 39a66b8d ("[PATCH] USB: CP2101 Add support for flow control")
Cc: stable <stable@vger.kernel.org>     # 2.6.12
Signed-off-by: NJohan Hovold <johan@kernel.org>

A subset of all CH341 devices don't support a real break condition. This
fact is already used in the "ch341_detect_quirks" function. With this
change a quirk is implemented to simulate a break condition by
temporarily lowering the baud rate and sending a NUL byte.

The primary drawbacks of this approach are that the duration of the
break can't be controlled by userland and that data incoming during
a simulated break is corrupted.

The "TTY_DRIVER_HARDWARE_BREAK" serial driver flag was investigated as
an alternative. It's a driver-wide flag and would've required
significant changes to the serial and USB-serial driver frameworks to
expose it for individual USB-serial adapters.

Tested by sending a break condition and watching the TX pin using an
oscilloscope.
Signed-off-by: NMichael Hanselmann <public@hansmi.ch>
Link: https://lore.kernel.org/r/f34a9b6e-ec2a-0873-e97b-2d5b2170e2ff@msgid.hansmi.ch
[ johan: condense info message ]
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add support for enabling hardware flow control using the 'r' command
line option.

This also avoids a W=1 (-Wunused-but-set-variable) warning.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Drop two unused stub functions which only served as documentation.

This also avoids a W=1 (-Wunused-but-set-variable) warning.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Log failure to update the line settings in set_termios().

This also avoids a W=1 (-Wunused-but-set-variable) warning.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Drop the unused firmware reset status which would already have been
logged.

This suppresses the corresponding W=1 (-Wunused-but-set-variable)
warning.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The driver is submitting URBs in various completion callbacks without
bothering to log errors yet still assigned the return value to temporary
variables. Let's drop those temporaries.

This suppresses the corresponding W=1 (-Wunused-but-set-variable)
warnings.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Don't compile the four unused packet definitions but keep them around
for documentation purposes.

This avoids the corresponding W=1 (-Wunused-const-variable) warning.
Reviewed-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

The line-speed algorithm clamps the requested value to the supported
range instead of bailing out on unsupported values.

Provide min and max macros and indicate how they are derived instead of
hardcoding the limits.

Note that the algorithm depends on the minimum rate (45.78 bps)
being rounded up (and the maximum rate being rounded down) to avoid
special casing.
Suggested-by: NMichael Hanselmann <public@hansmi.ch>
Link: https://lore.kernel.org/r/20200630095756.GZ3334@localhostSigned-off-by: NJohan Hovold <johan@kernel.org>

Add constants for the prescaler and divisor registers. Document and
name register 0x25, and put the LCR define to more use.

The 0x25 register (CH341_REG_LCR2) is only used by CH341 chips before
version 0x30 and is involved in configuring the line control parameters.
It's not known to the author whether there any such chips in the wild,
and Linux' ch341 driver never supported them. For chip version 0x30 and
above the 0x25 register is always set to zero. The alternative would've
been to not set the register at all, but that may have unintended
effects.
Signed-off-by: NMichael Hanselmann <public@hansmi.ch>
Link: https://lore.kernel.org/r/2e80916d-1be8-dc0f-abf9-adc0feea1803@msgid.hansmi.ch
[ johan: fix up comment ]
Signed-off-by: NJohan Hovold <johan@kernel.org>

The sierra driver had two different functions for trying to determine
different quirks that did the same exact thing.  Remove one and rename
things to make it more obvious exactly what the different lists do.

Cc: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20200618094300.1887727-6-gregkh@linuxfoundation.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Better describe what is happening with a list of devices that are being
ignored by the driver.

Cc: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20200618094300.1887727-5-gregkh@linuxfoundation.orgSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since commit 84af7a61 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'
Signed-off-by: NMasahiro Yamada <masahiroy@kernel.org>

Michael Hanselmann reports that

	[a] subset of all CH341 devices stop responding to bulk
	transfers, usually after the third byte, when the highest
	prescaler bit (0b100) is set. There is one exception, namely a
	prescaler of exactly 0b111 (fact=1, ps=3).

Fix this by forcing a lower base clock (fact = 0) whenever needed.

This specifically makes the standard rates 110, 134 and 200 bps work
again with these devices.

Fixes: 35714565 ("USB: serial: ch341: reimplement line-speed handling")
Cc: stable <stable@vger.kernel.org>	# 5.5
Reported-by: NMichael Hanselmann <public@hansmi.ch>
Link: https://lore.kernel.org/r/20200514141743.GE25962@localhostSigned-off-by: NJohan Hovold <johan@kernel.org>

A subset of CH341 devices does not support all features, namely the
prescaler is limited to a reduced precision and there is no support for
sending a RS232 break condition. This patch adds a detection function
which will be extended to set quirk flags as they're implemented.

The author's affected device has an imprint of "340" on the
turquoise-colored plug, but not all such devices appear to be affected.
Signed-off-by: NMichael Hanselmann <public@hansmi.ch>
Link: https://lore.kernel.org/r/1e1ae0da6082bb528a44ef323d4e1d3733d38858.1585697281.git.public@hansmi.ch
[ johan: use long type for quirks; rephrase and use port device for
	 messages; handle short reads; set quirk flags directly in
	 helper function ]
Cc: stable <stable@vger.kernel.org>	# 5.5
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add Telit LE910C1-EUX compositions:

	0x1031: tty, tty, tty, rmnet
	0x1033: tty, tty, tty, ecm
Signed-off-by: NDaniele Palmas <dnlplm@gmail.com>
Link: https://lore.kernel.org/r/20200525211106.27338-1-dnlplm@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add support for Dell Wireless 5816e Download Mode (AKA boot & hold mode /
QDL download mode) to drivers/usb/serial/qcserial.c

This is required to update device firmware.
Signed-off-by: NMatt Jolly <Kangie@footclan.ninja>
Cc: stable@vger.kernel.org
Signed-off-by: NJohan Hovold <johan@kernel.org>

usb_wwan_indat_callback() shouldn't resubmit rx urb if the previous urb
status is a fatal error. Or the usb controller would keep processing the
new urbs then run into interrupt storm, and has no chance to recover.

Fixes: 6c1ee66a ("USB-Serial: Fix error handling of usb_wwan")
Cc: stable@vger.kernel.org
Signed-off-by: NBin Liu <b-liu@ti.com>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Add support for Dell Wireless 5816e to drivers/usb/serial/qcserial.c
Signed-off-by: NMatt Jolly <Kangie@footclan.ninja>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

This patch corrects the SPDX License Identifier style in
header files related to USB Serial device configuration.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used).

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.
Suggested-by: NJoe Perches <joe@perches.com>
Signed-off-by: NNishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: NJohan Hovold <johan@kernel.org>

We must not process packets shorter than a packet ID
Signed-off-by: NOliver Neukum <oneukum@suse.com>
Reported-and-tested-by: syzbot+d29e9263e13ce0b9f4fd@syzkaller.appspotmail.com
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

Fix slab-out-of-bounds read in the interrupt-URB completion handler.

The boundary condition should be (length - 1) as we access
data[position + 1].

Reported-and-tested-by: syzbot+37ba33391ad5f3935bbd@syzkaller.appspotmail.com
Signed-off-by: NQiujun Huang <hqjagain@gmail.com>
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

This modem is embedded on dlink dwr-960 router.
The oem configuration states:

T: Bus=01 Lev=01 Prnt=01 Port=00 Cnt=01 Dev#= 2 Spd=480 MxCh= 0
D: Ver= 2.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=1435 ProdID=d191 Rev=ff.ff
S: Manufacturer=Android
S: Product=Android
S: SerialNumber=0123456789ABCDEF
C:* #Ifs= 6 Cfg#= 1 Atr=80 MxPwr=500mA
I:* If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=(none)
E: Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E: Ad=01(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 1 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=42 Prot=01 Driver=(none)
E: Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E: Ad=82(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)
E: Ad=84(I) Atr=03(Int.) MxPS= 10 Ivl=32ms
E: Ad=83(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E: Ad=03(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=(none)
E: Ad=86(I) Atr=03(Int.) MxPS= 10 Ivl=32ms
E: Ad=85(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E: Ad=04(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 4 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=qmi_wwan
E: Ad=88(I) Atr=03(Int.) MxPS= 8 Ivl=32ms
E: Ad=87(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E: Ad=05(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 5 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=(none)
E: Ad=89(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E: Ad=06(O) Atr=02(Bulk) MxPS= 512 Ivl=125us

Tested on openwrt distribution
Signed-off-by: NPawel Dembicki <paweldembicki@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>

BroadMobi BM806U is an Qualcomm MDM9225 based 3G/4G modem.
Tested hardware BM806U is mounted on D-Link DWR-921-C3 router.

T:  Bus=01 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#=  2 Spd=480  MxCh= 0
D:  Ver= 2.01 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=2020 ProdID=2033 Rev= 2.28
S:  Manufacturer=Mobile Connect
S:  Product=Mobile Connect
S:  SerialNumber=f842866cfd5a
C:* #Ifs= 5 Cfg#= 1 Atr=80 MxPwr=500mA
I:* If#= 0 Alt= 0 #EPs= 2 Cls=ff(vend.) Sub=ff Prot=ff Driver=option
E:  Ad=81(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=01(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 1 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
E:  Ad=83(I) Atr=03(Int.) MxPS=  10 Ivl=32ms
E:  Ad=82(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=02(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 2 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
E:  Ad=85(I) Atr=03(Int.) MxPS=  10 Ivl=32ms
E:  Ad=84(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=03(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 3 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=00 Prot=00 Driver=option
E:  Ad=87(I) Atr=03(Int.) MxPS=  10 Ivl=32ms
E:  Ad=86(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=04(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
I:* If#= 4 Alt= 0 #EPs= 3 Cls=ff(vend.) Sub=ff Prot=ff Driver=qmi_wwan
E:  Ad=89(I) Atr=03(Int.) MxPS=   8 Ivl=32ms
E:  Ad=88(I) Atr=02(Bulk) MxPS= 512 Ivl=0ms
E:  Ad=05(O) Atr=02(Bulk) MxPS= 512 Ivl=0ms
Co-developed-by: NCezary Jackiewicz <cezary@eko.one.pl>
Signed-off-by: NCezary Jackiewicz <cezary@eko.one.pl>
Signed-off-by: NPawel Dembicki <paweldembicki@gmail.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NJohan Hovold <johan@kernel.org>