From: Patrice Chotard patrice.chotard@st.com
commit 3c0af1dd2fe78adc02fe21f6cfe7d6cb8602573e upstream.
spi_master_put() must only be called in .probe() in case of error.
As devm_spi_register_master() is used during probe, spi_master_put() mustn't be called in .remove() callback.
It fixes the following kernel WARNING/Oops when executing echo "58003000.spi" > /sys/bus/platform/drivers/stm32-qspi/unbind :
------------[ cut here ]------------ WARNING: CPU: 1 PID: 496 at fs/kernfs/dir.c:1504 kernfs_remove_by_name_ns+0x9c/0xa4 kernfs: can not remove 'uevent', no directory Modules linked in: CPU: 1 PID: 496 Comm: sh Not tainted 5.3.0-rc1-00219-ga0e07bb51a37 #62 Hardware name: STM32 (Device Tree Support) [<c0111570>] (unwind_backtrace) from [<c010d384>] (show_stack+0x10/0x14) [<c010d384>] (show_stack) from [<c08db558>] (dump_stack+0xb4/0xc8) [<c08db558>] (dump_stack) from [<c01209d8>] (__warn.part.3+0xbc/0xd8) [<c01209d8>] (__warn.part.3) from [<c0120a5c>] (warn_slowpath_fmt+0x68/0x8c) [<c0120a5c>] (warn_slowpath_fmt) from [<c02e5844>] (kernfs_remove_by_name_ns+0x9c/0xa4) [<c02e5844>] (kernfs_remove_by_name_ns) from [<c05833a4>] (device_del+0x128/0x358) [<c05833a4>] (device_del) from [<c05835f8>] (device_unregister+0x24/0x64) [<c05835f8>] (device_unregister) from [<c0638dac>] (spi_unregister_controller+0x88/0xe8) [<c0638dac>] (spi_unregister_controller) from [<c058c580>] (release_nodes+0x1bc/0x200) [<c058c580>] (release_nodes) from [<c0588a44>] (device_release_driver_internal+0xec/0x1ac) [<c0588a44>] (device_release_driver_internal) from [<c0586840>] (unbind_store+0x60/0xd4) [<c0586840>] (unbind_store) from [<c02e64e8>] (kernfs_fop_write+0xe8/0x1c4) [<c02e64e8>] (kernfs_fop_write) from [<c0266b44>] (__vfs_write+0x2c/0x1c0) [<c0266b44>] (__vfs_write) from [<c02694c0>] (vfs_write+0xa4/0x184) [<c02694c0>] (vfs_write) from [<c0269710>] (ksys_write+0x58/0xd0) [<c0269710>] (ksys_write) from [<c0101000>] (ret_fast_syscall+0x0/0x54) Exception stack(0xdd289fa8 to 0xdd289ff0) 9fa0: 0000006c 000e20e8 00000001 000e20e8 0000000d 00000000 9fc0: 0000006c 000e20e8 b6f87da0 00000004 0000000d 0000000d 00000000 00000000 9fe0: 00000004 bee639b0 b6f2286b b6eaf6c6 ---[ end trace 1b15df8a02d76aef ]--- ------------[ cut here ]------------ WARNING: CPU: 1 PID: 496 at fs/kernfs/dir.c:1504 kernfs_remove_by_name_ns+0x9c/0xa4 kernfs: can not remove 'online', no directory Modules linked in: CPU: 1 PID: 496 Comm: sh Tainted: G W 5.3.0-rc1-00219-ga0e07bb51a37 #62 Hardware name: STM32 (Device Tree Support) [<c0111570>] (unwind_backtrace) from [<c010d384>] (show_stack+0x10/0x14) [<c010d384>] (show_stack) from [<c08db558>] (dump_stack+0xb4/0xc8) [<c08db558>] (dump_stack) from [<c01209d8>] (__warn.part.3+0xbc/0xd8) [<c01209d8>] (__warn.part.3) from [<c0120a5c>] (warn_slowpath_fmt+0x68/0x8c) [<c0120a5c>] (warn_slowpath_fmt) from [<c02e5844>] (kernfs_remove_by_name_ns+0x9c/0xa4) [<c02e5844>] (kernfs_remove_by_name_ns) from [<c0582488>] (device_remove_attrs+0x20/0x5c) [<c0582488>] (device_remove_attrs) from [<c05833b0>] (device_del+0x134/0x358) [<c05833b0>] (device_del) from [<c05835f8>] (device_unregister+0x24/0x64) [<c05835f8>] (device_unregister) from [<c0638dac>] (spi_unregister_controller+0x88/0xe8) [<c0638dac>] (spi_unregister_controller) from [<c058c580>] (release_nodes+0x1bc/0x200) [<c058c580>] (release_nodes) from [<c0588a44>] (device_release_driver_internal+0xec/0x1ac) [<c0588a44>] (device_release_driver_internal) from [<c0586840>] (unbind_store+0x60/0xd4) [<c0586840>] (unbind_store) from [<c02e64e8>] (kernfs_fop_write+0xe8/0x1c4) [<c02e64e8>] (kernfs_fop_write) from [<c0266b44>] (__vfs_write+0x2c/0x1c0) [<c0266b44>] (__vfs_write) from [<c02694c0>] (vfs_write+0xa4/0x184) [<c02694c0>] (vfs_write) from [<c0269710>] (ksys_write+0x58/0xd0) [<c0269710>] (ksys_write) from [<c0101000>] (ret_fast_syscall+0x0/0x54) Exception stack(0xdd289fa8 to 0xdd289ff0) 9fa0: 0000006c 000e20e8 00000001 000e20e8 0000000d 00000000 9fc0: 0000006c 000e20e8 b6f87da0 00000004 0000000d 0000000d 00000000 00000000 9fe0: 00000004 bee639b0 b6f2286b b6eaf6c6 ---[ end trace 1b15df8a02d76af0 ]--- 8<--- cut here --- Unable to handle kernel NULL pointer dereference at virtual address 00000050 pgd = e612f14d [00000050] *pgd=ff1f5835 Internal error: Oops: 17 [#1] SMP ARM Modules linked in: CPU: 1 PID: 496 Comm: sh Tainted: G W 5.3.0-rc1-00219-ga0e07bb51a37 #62 Hardware name: STM32 (Device Tree Support) PC is at kernfs_find_ns+0x8/0xfc LR is at kernfs_find_and_get_ns+0x30/0x48 pc : [<c02e49a4>] lr : [<c02e4ac8>] psr: 40010013 sp : dd289dac ip : 00000000 fp : 00000000 r10: 00000000 r9 : def6ec58 r8 : dd289e54 r7 : 00000000 r6 : c0abb234 r5 : 00000000 r4 : c0d26a30 r3 : ddab5080 r2 : 00000000 r1 : c0abb234 r0 : 00000000 Flags: nZcv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 10c5387d Table: dd11c06a DAC: 00000051 Process sh (pid: 496, stack limit = 0xe13a592d) Stack: (0xdd289dac to 0xdd28a000) 9da0: c0d26a30 00000000 c0abb234 00000000 c02e4ac8 9dc0: 00000000 c0976b44 def6ec00 dea53810 dd289e54 c02e864c c0a61a48 c0a4a5ec 9de0: c0d630a8 def6ec00 c0d04c48 c02e86e0 def6ec00 de909338 c0d04c48 c05833b0 9e00: 00000000 c0638144 dd289e54 def59900 00000000 475b3ee5 def6ec00 00000000 9e20: def6ec00 def59b80 dd289e54 def59900 00000000 c05835f8 def6ec00 c0638dac 9e40: 0000000a dea53810 c0d04c48 c058c580 dea53810 def59500 def59b80 475b3ee5 9e60: ddc63e00 dea53810 dea3fe10 c0d63a0c dea53810 ddc63e00 dd289f78 dd240d10 9e80: 00000000 c0588a44 c0d59a20 0000000d c0d63a0c c0586840 0000000d dd240d00 9ea0: 00000000 00000000 ddc63e00 c02e64e8 00000000 00000000 c0d04c48 dd9bbcc0 9ec0: c02e6400 dd289f78 00000000 000e20e8 0000000d c0266b44 00000055 00000cc0 9ee0: 000000e3 000e3000 dd11c000 dd11c000 00000000 00000000 00000000 00000000 9f00: ffeee38c dff99688 00000000 475b3ee5 00000001 dd289fb0 ddab5080 ddaa5800 9f20: 00000817 000e30ec dd9e7720 475b3ee5 ddaa583c 0000000d dd9bbcc0 000e20e8 9f40: dd289f78 00000000 000e20e8 0000000d 00000000 c02694c0 00000000 00000000 9f60: c0d04c48 dd9bbcc0 00000000 00000000 dd9bbcc0 c0269710 00000000 00000000 9f80: 000a91f4 475b3ee5 0000006c 000e20e8 b6f87da0 00000004 c0101204 dd288000 9fa0: 00000004 c0101000 0000006c 000e20e8 00000001 000e20e8 0000000d 00000000 9fc0: 0000006c 000e20e8 b6f87da0 00000004 0000000d 0000000d 00000000 00000000 9fe0: 00000004 bee639b0 b6f2286b b6eaf6c6 600e0030 00000001 00000000 00000000 [<c02e49a4>] (kernfs_find_ns) from [<def6ec00>] (0xdef6ec00) Code: ebf8eeab c0dc50b8 e92d40f0 e292c000 (e1d035b0) ---[ end trace 1b15df8a02d76af1 ]---
Fixes: a88eceb17ac7 ("spi: stm32-qspi: add spi_master_put in release function") Cc: stable@vger.kernel.org Signed-off-by: Patrice Chotard patrice.chotard@st.com Link: https://lore.kernel.org/r/20191004123606.17241-1-patrice.chotard@st.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/spi/spi-stm32-qspi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/spi/spi-stm32-qspi.c +++ b/drivers/spi/spi-stm32-qspi.c @@ -528,7 +528,6 @@ static void stm32_qspi_release(struct st stm32_qspi_dma_free(qspi); mutex_destroy(&qspi->lock); clk_disable_unprepare(qspi->clk); - spi_master_put(qspi->ctrl); }
static int stm32_qspi_probe(struct platform_device *pdev) @@ -629,6 +628,8 @@ static int stm32_qspi_probe(struct platf
err: stm32_qspi_release(qspi); + spi_master_put(qspi->ctrl); + return ret; }