linux-stable.git/drivers/spi, branch v6.2.2

Merge tag 'spi-v6.2-rc8-abi' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

2023-02-16T20:01:46+00:00

Pull spi fix from Mark Brown:
 "One more last minute patch for v6.2 updating the parsing of the newly
  added spi-cs-setup-delay-ns.

  It's been pointed out that due to the way DT parsing works the change
  in property size is ABI visible so let's not let a release go out
  without it being fixed. The change got split from some earlier ABI
  related fixes to the property since the first version sent had a build
  error"

* tag 'spi-v6.2-rc8-abi' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: Use a 32-bit DT property for spi-cs-setup-delay-ns

spi: spidev: fix a recursive locking error

2023-01-27T16:38:05+00:00

When calling spidev_message() from the one of the ioctl() callbacks, the
spi_lock is already taken. When we then end up calling spidev_sync(), we
get the following splat:

[  214.047619]
[  214.049198] ============================================
[  214.054533] WARNING: possible recursive locking detected
[  214.059858] 6.2.0-rc3-0.0.0-devel+git.97ec4d559d93 #1 Not tainted
[  214.065969] --------------------------------------------
[  214.071290] spidev_test/1454 is trying to acquire lock:
[  214.076530] c4925dbc (&spidev->spi_lock){+.+.}-{3:3}, at: spidev_ioctl+0x8e0/0xab8
[  214.084164]
[  214.084164] but task is already holding lock:
[  214.090007] c4925dbc (&spidev->spi_lock){+.+.}-{3:3}, at: spidev_ioctl+0x44/0xab8
[  214.097537]
[  214.097537] other info that might help us debug this:
[  214.104075]  Possible unsafe locking scenario:
[  214.104075]
[  214.110004]        CPU0
[  214.112461]        ----
[  214.114916]   lock(&spidev->spi_lock);
[  214.118687]   lock(&spidev->spi_lock);
[  214.122457]
[  214.122457]  *** DEADLOCK ***
[  214.122457]
[  214.128386]  May be due to missing lock nesting notation
[  214.128386]
[  214.135183] 2 locks held by spidev_test/1454:
[  214.139553]  #0: c4925dbc (&spidev->spi_lock){+.+.}-{3:3}, at: spidev_ioctl+0x44/0xab8
[  214.147524]  #1: c4925e14 (&spidev->buf_lock){+.+.}-{3:3}, at: spidev_ioctl+0x70/0xab8
[  214.155493]
[  214.155493] stack backtrace:
[  214.159861] CPU: 0 PID: 1454 Comm: spidev_test Not tainted 6.2.0-rc3-0.0.0-devel+git.97ec4d559d93 #1
[  214.169012] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[  214.175555]  unwind_backtrace from show_stack+0x10/0x14
[  214.180819]  show_stack from dump_stack_lvl+0x60/0x90
[  214.185900]  dump_stack_lvl from __lock_acquire+0x874/0x2858
[  214.191584]  __lock_acquire from lock_acquire+0xfc/0x378
[  214.196918]  lock_acquire from __mutex_lock+0x9c/0x8a8
[  214.202083]  __mutex_lock from mutex_lock_nested+0x1c/0x24
[  214.207597]  mutex_lock_nested from spidev_ioctl+0x8e0/0xab8
[  214.213284]  spidev_ioctl from sys_ioctl+0x4d0/0xe2c
[  214.218277]  sys_ioctl from ret_fast_syscall+0x0/0x1c
[  214.223351] Exception stack(0xe75cdfa8 to 0xe75cdff0)
[  214.228422] dfa0:                   00000000 00001000 00000003 40206b00 bee266e8 bee266e0
[  214.236617] dfc0: 00000000 00001000 006a71a0 00000036 004c0040 004bfd18 00000000 00000003
[  214.244809] dfe0: 00000036 bee266c8 b6f16dc5 b6e8e5f6

Fix it by introducing an unlocked variant of spidev_sync() and calling it
from spidev_message() while other users who don't check the spidev->spi's
existence keep on using the locking flavor.

Reported-by: Francesco Dolcini 
Fixes: 1f4d2dd45b6e ("spi: spidev: fix a race condition when accessing spidev->spi")
Signed-off-by: Bartosz Golaszewski 
Tested-by: Max Krummenacher 
Link: https://lore.kernel.org/r/20230116144149.305560-1-brgl@bgdev.pl
Signed-off-by: Mark Brown

spi: dw: Fix wrong FIFO level setting for long xfers

2023-01-27T16:38:04+00:00

Due to using the u16 type in the min_t() macros the SPI transfer length
will be cast to word before participating in the conditional statement
implied by the macro. Thus if the transfer length is greater than 64KB the
Tx/Rx FIFO threshold level value will be determined by the leftover of the
truncated after the type-case length. In the worst case it will cause the
dramatical performance drop due to the "Tx FIFO Empty" or "Rx FIFO Full"
interrupts triggered on each xfer word sent/received to/from the bus.

The problem can be easily fixed by specifying the unsigned int type in the
min_t() macros thus preventing the possible data loss.

Fixes: ea11370fffdf ("spi: dw: get TX level without an additional variable")
Reported-by: Sergey Nazarov 
Signed-off-by: Serge Semin 
Reviewed-by: Andy Shevchenko 
Link: https://lore.kernel.org/r/20230113185942.2516-1-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown

spi: Use a 32-bit DT property for spi-cs-setup-delay-ns

2023-01-13T12:31:49+00:00

65us is not a reasonable maximum for this property, as some devices
might need a much longer setup time (e.g. those driven by firmware on
the other end). Plus, device tree property values are in 32-bit cells
and smaller widths should not be used without good reason.

Also move the logic to a helper function, since this will later be used
to parse other CS delay properties too.

Fixes: 33a2fde5f77b ("spi: Introduce spi-cs-setup-ns property")
Signed-off-by: Janne Grunau 
Signed-off-by: Hector Martin 
Link: https://lore.kernel.org/r/20230113102309.18308-2-marcan@marcan.st
Signed-off-by: Mark Brown

spi: Merge rename of spi-cs-setup-ns DT property

2023-01-11T14:15:22+00:00

The newly added spi-cs-setup-ns doesn't really fit with the existing
property names for delays, rename it so that it does before it makes it
into a release and becomes ABI.

spi: spidev: remove debug messages that access spidev->spi without locking

2023-01-11T14:15:10+00:00

The two debug messages in spidev_open() dereference spidev->spi without
taking the lock and without checking if it's not null. This can lead to
a crash. Drop the messages as they're not needed - the user-space will
get informed about ENOMEM with the syscall return value.

Signed-off-by: Bartosz Golaszewski 
Link: https://lore.kernel.org/r/20230106100719.196243-2-brgl@bgdev.pl
Signed-off-by: Mark Brown

spi: spidev: fix a race condition when accessing spidev->spi

2023-01-11T14:15:10+00:00

There's a spinlock in place that is taken in file_operations callbacks
whenever we check if spidev->spi is still alive (not null). It's also
taken when spidev->spi is set to NULL in remove().

This however doesn't protect the code against driver unbind event while
one of the syscalls is still in progress. To that end we need a lock taken
continuously as long as we may still access spidev->spi. As both the file
ops and the remove callback are never called from interrupt context, we
can replace the spinlock with a mutex.

Signed-off-by: Bartosz Golaszewski 
Link: https://lore.kernel.org/r/20230106100719.196243-1-brgl@bgdev.pl
Signed-off-by: Mark Brown

spi: Rename spi-cs-setup-ns property to spi-cs-setup-delay-ns

2023-01-05T16:07:09+00:00

As mentioned in the corresponding DT binding commit, the naming scheme
for delay properties includes "delay" in the name, so let's keep that
consistent.

Fixes: 33a2fde5f77b ("spi: Introduce spi-cs-setup-ns property")
Signed-off-by: Hector Martin 
Link: https://lore.kernel.org/r/20230104093631.15611-3-marcan@marcan.st
Signed-off-by: Mark Brown

spi: cadence: Fix busy cycles calculation

2022-12-26T23:23:21+00:00

If xSPI is in x2/x4/x8 mode to calculate busy
cycles, busy bits count must be divided by the number
of lanes.
If opcommand is using 8 busy bits, but SPI is
in x4 mode, there will be only 2 busy cycles.

Signed-off-by: Witold Sadowski 
Reviewed-by: Chandrakala Chavva 
Reviewed-by: Sunil Kovvuri Goutham 
Link: https://lore.kernel.org/r/20221219144254.20883-2-wsadowski@marvell.com
Signed-off-by: Mark Brown

spi: mediatek: Enable irq before the spi registration

2022-12-26T23:23:21+00:00

If the irq is enabled after the spi si registered, there can be a race
with the initialization of the devices on the spi bus.

Eg:
mtk-spi 1100a000.spi: spi-mem transfer timeout
spi-nor: probe of spi0.0 failed with error -110
Unable to handle kernel NULL pointer dereference at virtual address
0000000000000010
...
Call trace:
 mtk_spi_can_dma+0x0/0x2c

Fixes: c6f7874687f7 ("spi: mediatek: Enable irq when pdata is ready")
Reported-by: Daniel Golle 
Signed-off-by: Ricardo Ribalda 
Tested-by: Daniel Golle 
Link: https://lore.kernel.org/r/20221225-mtk-spi-fixes-v1-0-bb6c14c232f8@chromium.org
Signed-off-by: Mark Brown