Implement suspend and resume callbacks in order to support system
suspend/hibernation.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add a clock notifier to dynamically handle frequency changes of the
input clock by reprogramming the UART in order to keep the baud rate
constant.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The original algorithm to find the best baud rate dividers does not necessarily
find the best set of dividers. And in the worst case may even write illegal
values to the hardware.
The new function should make better use of the hardware capabilities and be able
to provide valid settings for a wider range of baud rates and also input clocks.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It is possible that under certain circumstances xuartps_console_write is entered
while the UART disabled. When this happens the code will busy loop in
xuartps_console_putchar, since the character is never written and the TXEMPTY
flag is never set. The result is a system lockup. This patch force enables the
UART for the duration of xuartps_console_write to avoid this.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NJohn Linn <john.linn@xilinx.com>
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Changes to use the 64 byte FIFO depth and fix the issue
by clearing the txempty interrupt in isr status for tx
after filling in data in start_tx function
Signed-off-by: NSuneel Garapati <suneelg@xilinx.com>
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This allows KDB/KGDB to run.
Signed-off-by: NVlad Lungu <vlad.lungu@windriver.com>
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The Cadence UART does not do break detection, even if the
datasheet says it does. This patch adds break detection in
software (tested in 8N1 mode only) and enables SYSRQ,
allowing for Break-g to enter KDB and all the other goodies.
Signed-off-by: NVlad Lungu <vlad.lungu@windriver.com>
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use the device managed interface for memory allocation, simplifying
error paths.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use the device managed interface for clocks, simplifying error paths.
Signed-off-by: NSoren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

On older SoC, the "name" field is not filled in the register map.
Fix the way to figure out if the serial port is an uart or an usart for these
older products (with corresponding properties).
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since commit 055560b0 (serial: at91:
distinguish usart and uart) the older products which do not have a
name field in their register map are unable to use their serial output.
As the main console output is usually the serial interface (aka DBGU) it
is pretty unfortunate.
So, instead of failing during probe() we just silently configure the serial
peripheral as an uart. It allows us to use these serial outputs.
The proper solution is proposed in another patch.
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This adds support for Fintek's 4, 8, and 12 port PCIE serial cards.

Thanks to Fintek for the sample devices, and the spec needed in order to
implement this.

Cc: Amanda Ying <amanda_ying@fintek.com.tw>
Cc: Felix Shih <felix_shih@fintek.com.tw>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

I worried that the delay of the sdma_run_channel0() maybe too long for
interrupt context, so I added the workqueues for RX/TX DMA.

But tested with bluetooth device, I find that the delay of sdma_run_channel0()
is about 8us (tested in imx6dl sabreauto board). I think the delay
is acceptable.

This patch removes the RX/TX workqueues for DMA, it makes the
code more clear.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Use the dmaengine_tx_status to simplify the code, do not change any logic.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When the (xmit->tail > xmit->head) is true and the xmit->head is 0,
we only need one DMA scatterlist in actually. Current code uses two DMA
scatterlists in this case, this is obviously wrong.

This patch fixes it.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Assume the following situation:

  If the DMA is enabled, and the a TX DMA operation is working,
But we have not issued the TX DMA operation (or we have issued the
TX DMA operation with dma_async_issue_pending(), but the DMA has not
started to move the data from the memory to the TXFIFO).

At this time, we may get the wrong status of the transmitter when we
call the imx_tx_empty. In such situation, only check the USR2_TXDC
does not enough for us.

This patch checks the DMA's situation, and return 0 when the TX DMA is
working.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The current driver does not implement the flush_buffer hook for
uart_ops. When we enable the DMA for the driver, and test it with Bluetooth,
we may meet the following bug for TX:

    [1] User application may call the flush operation at any time.
        The uart_flush_buffer() calls the uart_circ_clear() to set
        the xmit->head and xmit->tail with 0.

    [2] The TX DMA callback can be called at any time too.
        The dma_tx_call() will update the xmit->tail.

    If [2] occurs just after the [1], we will get the wrong xmit->tail.

This patch implements the flush_buffer hook to fix this issue.
Signed-off-by: NHuang Shijie <b32955@freescale.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This callback is gone and not coming back, so will not be
supported later.

Cc: Johan Hovold <jhovold@gmail.com>
Acked-by: NDarren Hart <dvhart@linux.intel.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This callback is gone and not coming back, so will not be
supported later.

Cc: Gerhard Sittig <gsi@denx.de>
Cc: Anatolij Gustschin <agust@denx.de>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This callback is unused by the serial core since pre-git days
and is not coming back. Delete it. Enabling wakeup on the
SA1100 platforms should be done in the suspend() callback
so the platform hook is left in the serial port struct for
later enablement.

Cc: Russell King <linux@arm.linux.org.uk>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This callback is unused by the serial core since pre-git days
and is not coming back. Delete it. Enabling wakeup on the
OMAP serial driver is done through other runpaths these days.

Cc: Tony Lindgren <tony@atomide.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

test echo_buf() result for ECHO_OP_START
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Acked-by: NPeter Hurley <peter@hurleysoftware.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

These aren't necessary after switch and while blocks.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

There is a race between termios configuration and xmit that can cause the
intel_mid_ssp_spi driver to stall.

Serializing spi transactions fixes the problem.
Signed-off-by: NBin Gao <bin.gao@intel.com>
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We should check the validity of the irq number before calling
disable_irq() and enable_irq() in the suspend/resume function,
as "max->irq == 0" means the irq is not enabled for max3110
device, otherwise it will hurt device whose irq number is really 0.
Signed-off-by: NFeng Tang <feng.tang@intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Add calls to clk_prepare and unprepare so that EMMA Mobile EV2 can
migrate to the common clock framework.
Signed-off-by: NShinya Kuribayashi <shinya.kuribayashi.px@renesas.com>
[takashi.yoshii.ze@renesas.com: edited for conflicts]
Signed-off-by: NTakashi Yoshii <takashi.yoshii.zj@renesas.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NMagnus Damm <damm@opensource.se>
Signed-off-by: NSimon Horman <horms+renesas@verge.net.au>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Turn the initial value of sysctl kernel.sysrq (SYSRQ_DEFAULT_ENABLE)
into a Kconfig variable.

Original version by Bastian Blank <waldi@debian.org>.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch proposes to remove the use of the IRQF_DISABLED flag

It's a NOOP since 2.6.35 and it will be removed one day.
Signed-off-by: NMichael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch proposes to remove the use of the IRQF_DISABLED flag

It's a NOOP since 2.6.35 and it will be removed one day.
Signed-off-by: NMichael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When DMA is enabled (with hardware flow control enabled) the FIFO size
must be set to the size of the DMA buffer, as this is the size the tty
subsystem can use.
Signed-off-by: NHector Palacios <hector.palacios@digi.com>
Reviewed-by: NMarek Vasut <marex@denx.de>
Acked-by: NUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

We need to free the ld_active list head before jumping into the callback
routine. Otherwise the callback could run into issue_pending and change
our ld_active list head we just going to free. This will run the channel
list into an currupted and undefined state.
Signed-off-by: NMichael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

The tasklet and irqhandler are using spin_lock while other routines are
using spin_lock_irqsave/restore. This leads to lockdep issues as
described bellow. This patch is changing the code to use
spinlock_irq_save/restore in both code pathes.

As imxdma_xfer_desc always gets called with spin_lock_irqsave lock held,
this patch also removes the spare call inside the routine to avoid
double locking.

[  403.358162] =================================
[  403.362549] [ INFO: inconsistent lock state ]
[  403.366945] 3.10.0-20130823+ #904 Not tainted
[  403.371331] ---------------------------------
[  403.375721] inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
[  403.381769] swapper/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
[  403.386762]  (&(&imxdma->lock)->rlock){?.-...}, at: [<c019d77c>] imxdma_tasklet+0x20/0x134
[  403.395201] {IN-HARDIRQ-W} state was registered at:
[  403.400108]   [<c004b264>] mark_lock+0x2a0/0x6b4
[  403.404798]   [<c004d7c8>] __lock_acquire+0x650/0x1a64
[  403.410004]   [<c004f15c>] lock_acquire+0x94/0xa8
[  403.414773]   [<c02f74e4>] _raw_spin_lock+0x54/0x8c
[  403.419720]   [<c019d094>] dma_irq_handler+0x78/0x254
[  403.424845]   [<c0061124>] handle_irq_event_percpu+0x38/0x1b4
[  403.430670]   [<c00612e4>] handle_irq_event+0x44/0x64
[  403.435789]   [<c0063a70>] handle_level_irq+0xd8/0xf0
[  403.440903]   [<c0060a20>] generic_handle_irq+0x28/0x38
[  403.446194]   [<c0009cc4>] handle_IRQ+0x68/0x8c
[  403.450789]   [<c0008714>] avic_handle_irq+0x3c/0x48
[  403.455811]   [<c0008f84>] __irq_svc+0x44/0x74
[  403.460314]   [<c0040b04>] cpu_startup_entry+0x88/0xf4
[  403.465525]   [<c02f00d0>] rest_init+0xb8/0xe0
[  403.470045]   [<c03e07dc>] start_kernel+0x28c/0x2d4
[  403.474986]   [<a0008040>] 0xa0008040
[  403.478709] irq event stamp: 50854
[  403.482140] hardirqs last  enabled at (50854): [<c001c6b8>] tasklet_action+0x38/0xdc
[  403.489954] hardirqs last disabled at (50853): [<c001c6a0>] tasklet_action+0x20/0xdc
[  403.497761] softirqs last  enabled at (50850): [<c001bc64>] _local_bh_enable+0x14/0x18
[  403.505741] softirqs last disabled at (50851): [<c001c268>] irq_exit+0x88/0xdc
[  403.513026]
[  403.513026] other info that might help us debug this:
[  403.519593]  Possible unsafe locking scenario:
[  403.519593]
[  403.525548]        CPU0
[  403.528020]        ----
[  403.530491]   lock(&(&imxdma->lock)->rlock);
[  403.534828]   <Interrupt>
[  403.537474]     lock(&(&imxdma->lock)->rlock);
[  403.541983]
[  403.541983]  *** DEADLOCK ***
[  403.541983]
[  403.547951] no locks held by swapper/0.
[  403.551813]
[  403.551813] stack backtrace:
[  403.556222] CPU: 0 PID: 0 Comm: swapper Not tainted 3.10.0-20130823+ #904
[  403.563039] Backtrace:
[  403.565581] [<c000b98c>] (dump_backtrace+0x0/0x10c) from [<c000bb28>] (show_stack+0x18/0x1c)
[  403.574054]  r6:00000000 r5:c05c51d8 r4:c040bd58 r3:00200000
[  403.579872] [<c000bb10>] (show_stack+0x0/0x1c) from [<c02f398c>] (dump_stack+0x20/0x28)
[  403.587955] [<c02f396c>] (dump_stack+0x0/0x28) from [<c02f29c8>] (print_usage_bug.part.28+0x224/0x28c)
[  403.597340] [<c02f27a4>] (print_usage_bug.part.28+0x0/0x28c) from [<c004b404>] (mark_lock+0x440/0x6b4)
[  403.606682]  r8:c004a41c r7:00000000 r6:c040bd58 r5:c040c040 r4:00000002
[  403.613566] [<c004afc4>] (mark_lock+0x0/0x6b4) from [<c004d844>] (__lock_acquire+0x6cc/0x1a64)
[  403.622244] [<c004d178>] (__lock_acquire+0x0/0x1a64) from [<c004f15c>] (lock_acquire+0x94/0xa8)
[  403.631010] [<c004f0c8>] (lock_acquire+0x0/0xa8) from [<c02f74e4>] (_raw_spin_lock+0x54/0x8c)
[  403.639614] [<c02f7490>] (_raw_spin_lock+0x0/0x8c) from [<c019d77c>] (imxdma_tasklet+0x20/0x134)
[  403.648434]  r6:c3847010 r5:c040e890 r4:c38470d4
[  403.653194] [<c019d75c>] (imxdma_tasklet+0x0/0x134) from [<c001c70c>] (tasklet_action+0x8c/0xdc)
[  403.662013]  r8:c0599160 r7:00000000 r6:00000000 r5:c040e890 r4:c3847114 r3:c019d75c
[  403.670042] [<c001c680>] (tasklet_action+0x0/0xdc) from [<c001bd4c>] (__do_softirq+0xe4/0x1f0)
[  403.678687]  r7:00000101 r6:c0402000 r5:c059919c r4:00000001
[  403.684498] [<c001bc68>] (__do_softirq+0x0/0x1f0) from [<c001c268>] (irq_exit+0x88/0xdc)
[  403.692652] [<c001c1e0>] (irq_exit+0x0/0xdc) from [<c0009cc8>] (handle_IRQ+0x6c/0x8c)
[  403.700514]  r4:00000030 r3:00000110
[  403.704192] [<c0009c5c>] (handle_IRQ+0x0/0x8c) from [<c0008714>] (avic_handle_irq+0x3c/0x48)
[  403.712664]  r5:c0403f28 r4:c0593ebc
[  403.716343] [<c00086d8>] (avic_handle_irq+0x0/0x48) from [<c0008f84>] (__irq_svc+0x44/0x74)
[  403.724733] Exception stack(0xc0403f28 to 0xc0403f70)
[  403.729841] 3f20:                   00000001 00000004 00000000 20000013 c0402000 c04104a8
[  403.738078] 3f40: 00000002 c0b69620 a0004000 41069264 a03fb5f4 c0403f7c c0403f40 c0403f70
[  403.746301] 3f60: c004b92c c0009e74 20000013 ffffffff
[  403.751383]  r6:ffffffff r5:20000013 r4:c0009e74 r3:c004b92c
[  403.757210] [<c0009e30>] (arch_cpu_idle+0x0/0x4c) from [<c0040b04>] (cpu_startup_entry+0x88/0xf4)
[  403.766161] [<c0040a7c>] (cpu_startup_entry+0x0/0xf4) from [<c02f00d0>] (rest_init+0xb8/0xe0)
[  403.774753] [<c02f0018>] (rest_init+0x0/0xe0) from [<c03e07dc>] (start_kernel+0x28c/0x2d4)
[  403.783051]  r6:c03fc484 r5:ffffffff r4:c040a0e0
[  403.787797] [<c03e0550>] (start_kernel+0x0/0x2d4) from [<a0008040>] (0xa0008040)
Signed-off-by: NMichael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

When perparing cyclic_dma buffers by the sound layer, it will dump the
following lockdep trace. The leading snd_pcm_action_single get called
with read_lock_irq called. To fix this, we change the kcalloc call from
GFP_KERNEL to GFP_ATOMIC.

WARNING: at kernel/lockdep.c:2740 lockdep_trace_alloc+0xcc/0x114()
DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags))
Modules linked in:
CPU: 0 PID: 832 Comm: aplay Not tainted 3.11.0-20130823+ #903
Backtrace:
[<c000b98c>] (dump_backtrace+0x0/0x10c) from [<c000bb28>] (show_stack+0x18/0x1c)
 r6:c004c090 r5:00000009 r4:c2e0bd18 r3:00404000
[<c000bb10>] (show_stack+0x0/0x1c) from [<c02f397c>] (dump_stack+0x20/0x28)
[<c02f395c>] (dump_stack+0x0/0x28) from [<c001531c>] (warn_slowpath_common+0x54/0x70)
[<c00152c8>] (warn_slowpath_common+0x0/0x70) from [<c00153dc>] (warn_slowpath_fmt+0x38/0x40)
 r8:00004000 r7:a3b90000 r6:000080d0 r5:60000093 r4:c2e0a000 r3:00000009
[<c00153a4>] (warn_slowpath_fmt+0x0/0x40) from [<c004c090>] (lockdep_trace_alloc+0xcc/0x114)
 r3:c03955d8 r2:c03907db
[<c004bfc4>] (lockdep_trace_alloc+0x0/0x114) from [<c008f16c>] (__kmalloc+0x34/0x118)
 r6:000080d0 r5:c3800120 r4:000080d0 r3:c040a0f8
[<c008f138>] (__kmalloc+0x0/0x118) from [<c019c95c>] (imxdma_prep_dma_cyclic+0x64/0x168)
 r7:a3b90000 r6:00000004 r5:c39d8420 r4:c3847150
[<c019c8f8>] (imxdma_prep_dma_cyclic+0x0/0x168) from [<c024618c>] (snd_dmaengine_pcm_trigger+0xa8/0x160)
[<c02460e4>] (snd_dmaengine_pcm_trigger+0x0/0x160) from [<c0241fa8>] (soc_pcm_trigger+0x90/0xb4)
 r8:c058c7b0 r7:c3b8140c r6:c39da560 r5:00000001 r4:c3b81000
[<c0241f18>] (soc_pcm_trigger+0x0/0xb4) from [<c022ece4>] (snd_pcm_do_start+0x2c/0x38)
 r7:00000000 r6:00000003 r5:c058c7b0 r4:c3b81000
[<c022ecb8>] (snd_pcm_do_start+0x0/0x38) from [<c022e958>] (snd_pcm_action_single+0x40/0x6c)
[<c022e918>] (snd_pcm_action_single+0x0/0x6c) from [<c022ea64>] (snd_pcm_action_lock_irq+0x7c/0x9c)
 r7:00000003 r6:c3b810f0 r5:c3b810f0 r4:c3b81000
[<c022e9e8>] (snd_pcm_action_lock_irq+0x0/0x9c) from [<c023009c>] (snd_pcm_common_ioctl1+0x7f8/0xfd0)
 r8:c3b7f888 r7:005407b8 r6:c2c991c0 r5:c3b81000 r4:c3b81000 r3:00004142
[<c022f8a4>] (snd_pcm_common_ioctl1+0x0/0xfd0) from [<c023117c>] (snd_pcm_playback_ioctl1+0x464/0x488)
[<c0230d18>] (snd_pcm_playback_ioctl1+0x0/0x488) from [<c02311d4>] (snd_pcm_playback_ioctl+0x34/0x40)
 r8:c3b7f888 r7:00004142 r6:00000004 r5:c2c991c0 r4:005407b8
[<c02311a0>] (snd_pcm_playback_ioctl+0x0/0x40) from [<c00a14a4>] (vfs_ioctl+0x30/0x44)
[<c00a1474>] (vfs_ioctl+0x0/0x44) from [<c00a1fe8>] (do_vfs_ioctl+0x55c/0x5c0)
[<c00a1a8c>] (do_vfs_ioctl+0x0/0x5c0) from [<c00a208c>] (SyS_ioctl+0x40/0x68)
[<c00a204c>] (SyS_ioctl+0x0/0x68) from [<c0009380>] (ret_fast_syscall+0x0/0x44)
 r8:c0009544 r7:00000036 r6:bedeaa58 r5:00000000 r4:000000c0
Signed-off-by: NMichael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

Commit d0380e6c (early_printk:
consolidate random copies of identical code) added in 3.10 introduced
a check for con->index == -1 in early_console_register().

Initialize index to -1 for the xenboot console so earlyprintk=xen
works again.
Signed-off-by: NDavid Vrabel <david.vrabel@citrix.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: stable@vger.kernel.org
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Driver core clears the driver data to NULL after device_release
or on probe failure, so just remove it from here.

Driver core change:
"device-core: Ensure drvdata = NULL when no driver is bound"
(sha1: 0998d063)
Signed-off-by: NMichal Simek <michal.simek@xilinx.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

When configured with UART_16550_COMPATIBLE=NO or in versions prior to
the introduction of this option, the Designware UART will ignore writes
to the LCR if the UART is busy.  The current workaround saves a copy of
the last written LCR and re-writes it in the ISR for a special interrupt
that is raised when a write was ignored.

Unfortunately, interrupts are typically disabled prior to performing a
sequence of register writes that include the LCR so the point at which
the retry occurs is too late.  An example is serial8250_do_set_termios()
where an ignored LCR write results in the baud divisor not being set and
instead a garbage character is sent out the transmitter.

Furthermore, since serial_port_out() offers no way to indicate failure,
a serious effort must be made to ensure that the LCR is actually updated
before returning back to the caller.  This is difficult, however, as a
UART that was busy during the first attempt is likely to still be busy
when a subsequent attempt is made unless some extra action is taken.

This updated workaround reads back the LCR after each write to confirm
that the new value was accepted by the hardware.  Should the hardware
ignore a write, the TX/RX FIFOs are cleared and the receive buffer read
before attempting to rewrite the LCR out of the hope that doing so will
force the UART into an idle state.  While this may seem unnecessarily
aggressive, writes to the LCR are used to change the baud rate, parity,
stop bit, or data length so the data that may be lost is likely not
important.  Admittedly, this is far from ideal but it seems to be the
best that can be done given the hardware limitations.

Lastly, the revised workaround doesn't touch the LCR in the ISR, so it
avoids the possibility of a "serial8250: too much work for irq" lock up.
This problem is rare in real situations but can be reproduced easily by
wiring up two UARTs and running the following commands.

  # stty -F /dev/ttyS1 echo
  # stty -F /dev/ttyS2 echo
  # cat /dev/ttyS1 &
  [1] 375
  # echo asdf > /dev/ttyS1
  asdf

  [   27.700000] serial8250: too much work for irq96
  [   27.700000] serial8250: too much work for irq96
  [   27.710000] serial8250: too much work for irq96
  [   27.710000] serial8250: too much work for irq96
  [   27.720000] serial8250: too much work for irq96
  [   27.720000] serial8250: too much work for irq96
  [   27.730000] serial8250: too much work for irq96
  [   27.730000] serial8250: too much work for irq96
  [   27.740000] serial8250: too much work for irq96
Signed-off-by: NTim Kryger <tim.kryger@linaro.org>
Reviewed-by: NMatt Porter <matt.porter@linaro.org>
Reviewed-by: NMarkus Mayer <markus.mayer@linaro.org>
Reviewed-by: NHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Also clean up the last item of the pci id list to be "cleaner".
Signed-off-by: NDavid Cohen <david.a.cohen@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

The `insn_bits` handler `ni_65xx_dio_insn_bits()` has a `for` loop that
currently writes (optionally) and reads back up to 5 "ports" consisting
of 8 channels each.  It reads up to 32 1-bit channels but can only read
and write a whole port at once - it needs to handle up to 5 ports as the
first channel it reads might not be aligned on a port boundary.  It
breaks out of the loop early if the next port it handles is beyond the
final port on the card.  It also breaks out early on the 5th port in the
loop if the first channel was aligned.  Unfortunately, it doesn't check
that the current port it is dealing with belongs to the comedi subdevice
the `insn_bits` handler is acting on.  That's a bug.

Redo the `for` loop to terminate after the final port belonging to the
subdevice, changing the loop variable in the process to simplify things
a bit.  The `for` loop could now try and handle more than 5 ports if the
subdevice has more than 40 channels, but the test `if (bitshift >= 32)`
ensures it will break out early after 4 or 5 ports (depending on whether
the first channel is aligned on a port boundary).  (`bitshift` will be
between -7 and 7 inclusive on the first iteration, increasing by 8 for
each subsequent operation.)
Signed-off-by: NIan Abbott <abbotti@mev.co.uk>
Cc: <stable@vger.kernel.org> # 3.10.y 3.11.y 3.12.y
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This patch bumps the default number of tags allocated per session by
iscsi-target via transport_alloc_session_tags() -> percpu_ida_init()
by another (tag_num / 2).

This is done to take into account the tags waiting to be acknowledged
and released in iscsit_ack_from_expstatsn(), but who's number are not
directly limited by the CmdSN Window queue_depth being enforced by
the target.

Using a larger value here is also useful to prevent percpu_ida_alloc()
from having to steal tags from other CPUs when no tags are available
on the local CPU, while waiting for unacknowledged tags to be released.
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>

This patch converts iscsit_ack_from_expstatsn() to populate a local
ack_list of commands, and call iscsit_free_cmd() directly from RX
thread context, instead of using iscsit_add_cmd_to_immediate_queue()
to queue the acknowledged commands to be released from TX thread
context.

It is helpful to release the acknowledge commands as quickly as
possible, along with the associated percpu_ida tags, in order to
prevent percpu_ida_alloc() from having to steal tags from other
CPUs while waiting for iscsit_free_cmd() to happen from TX thread
context.
Signed-off-by: NNicholas Bellinger <nab@linux-iscsi.org>