user/sven/linux.git/drivers/spi, branch v6.2-rc8

spi: spidev: fix a recursive locking error

2023-01-27T16:38:05Z

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

2023-01-27T16:38:04Z

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

2023-01-11T14:15:22Z

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

2023-01-11T14:15:10Z

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

2023-01-11T14:15:10Z

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

2023-01-05T16:07:09Z

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

2022-12-26T23:23:21Z

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

2022-12-26T23:23:21Z

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

Merge tag 'spi-fix-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

2022-12-23T22:44:08Z

Pull spi fix from Mark Brown: "One driver specific change here which handles the case where a SPI device for some reason tries to change the bus speed during a message on fsl_spi hardware, this should be very unusual" * tag 'spi-fix-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: spi: fsl_spi: Don't change speed while chipselect is active

spi: fsl_spi: Don't change speed while chipselect is active

2022-12-14T14:24:51Z

Commit c9bfcb315104 ("spi_mpc83xx: much improved driver") made modifications to the driver to not perform speed changes while chipselect is active. But those changes where lost with the convertion to tranfer_one. Previous implementation was allowing speed changes during message transfer when cs_change flag was set. At the time being, core SPI does not provide any feature to change speed while chipselect is off, so do not allow any speed change during message transfer, and perform the transfer setup in prepare_message in order to set correct speed while chipselect is still off. Reported-by: Herve Codina Fixes: 64ca1a034f00 ("spi: fsl_spi: Convert to transfer_one") Cc: stable@vger.kernel.org Signed-off-by: Christophe Leroy Tested-by: Herve Codina Reviewed-by: Herve Codina Link: https://lore.kernel.org/r/8aab84c51aa330cf91f4b43782a1c483e150a4e3.1671025244.git.christophe.leroy@csgroup.eu Signed-off-by: Mark Brown