diff options
| author | Antonio Borneo <antonio.borneo@foss.st.com> | 2021-03-12 11:34:46 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2021-03-12 14:25:33 +0000 |
| commit | 8d559a64f00b59af9cc02b803ff52f6e6880a651 (patch) | |
| tree | 3237ab977c77371c3ee205ed1e705327ea39c698 /drivers/spi/spi-stm32.c | |
| parent | ffb597b2bd3cd78b9bfb68f536743cd46dbb2cc4 (diff) | |
spi: stm32: drop devres version of spi_register_master
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>
Diffstat (limited to 'drivers/spi/spi-stm32.c')
| -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 25c076461011..97cf3a2d4180 100644 --- a/drivers/spi/spi-stm32.c +++ b/drivers/spi/spi-stm32.c @@ -1929,7 +1929,7 @@ 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); @@ -1960,6 +1960,7 @@ 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) |