diff options
| author | Antonio Borneo <antonio.borneo@foss.st.com> | 2021-03-12 11:34:46 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-14 09:50:10 +0200 |
| commit | 0390f6f1d0bcd36d0ab22367498cc2c4619c05d8 (patch) | |
| tree | 61dbdb51f35a2ec17e3b15973d4671aeabeafc0e | |
| parent | 617ec35ed51f731a593ae7274228ef2cfc9cb781 (diff) | |
| download | kernel_replicant_linux-0390f6f1d0bcd36d0ab22367498cc2c4619c05d8.tar.gz kernel_replicant_linux-0390f6f1d0bcd36d0ab22367498cc2c4619c05d8.tar.bz2 kernel_replicant_linux-0390f6f1d0bcd36d0ab22367498cc2c4619c05d8.zip | |
spi: stm32: drop devres version of spi_register_master
[ Upstream commit 8d559a64f00b59af9cc02b803ff52f6e6880a651 ]
A call to spi_unregister_master() triggers calling remove()
for all the spi devices binded to the spi master.
Some spi device driver requires to "talk" with the spi device
during the remove(), e.g.:
- a LCD panel like drivers/gpu/drm/panel/panel-lg-lg4573.c
will turn off the backlighting sending a command over spi.
This implies that the spi master must be fully functional when
spi_unregister_master() is called, either if it is called
explicitly in the master's remove() code or implicitly by the
devres framework.
Devres calls devres_release_all() to release all the resources
"after" the remove() of the spi master driver (check code of
__device_release_driver() in drivers/base/dd.c).
If the spi master driver has an empty remove() then there would
be no issue; the devres_release_all() will release everything
in reverse order w.r.t. probe().
But if code in spi master driver remove() disables the spi or
makes it not functional (like in this spi-stm32), then devres
cannot be used safely for unregistering the spi master and the
binded spi devices.
Replace devm_spi_register_master() with spi_register_master()
and add spi_unregister_master() as first action in remove().
Fixes: dcbe0d84dfa5 ("spi: add driver for STM32 SPI controller")
Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com>
Signed-off-by: Alain Volmat <alain.volmat@foss.st.com>
Link: https://lore.kernel.org/r/1615545286-5395-1-git-send-email-alain.volmat@foss.st.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/spi/spi-stm32.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/spi/spi-stm32.c b/drivers/spi/spi-stm32.c index 53c4311cc6ab..8d8a32d46f2d 100644 --- a/drivers/spi/spi-stm32.c +++ b/drivers/spi/spi-stm32.c @@ -1950,7 +1950,7 @@ static int stm32_spi_probe(struct platform_device *pdev) pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); - ret = devm_spi_register_master(&pdev->dev, master); + ret = spi_register_master(master); if (ret) { dev_err(&pdev->dev, "spi master registration failed: %d\n", ret); @@ -1987,6 +1987,7 @@ static int stm32_spi_remove(struct platform_device *pdev) struct spi_master *master = platform_get_drvdata(pdev); struct stm32_spi *spi = spi_master_get_devdata(master); + spi_unregister_master(master); spi->cfg->disable(spi); if (master->dma_tx) |