summaryrefslogtreecommitdiff
path: root/drivers/spi/spi-bcm2835aux.c
diff options
context:
space:
mode:
authorLukas Wunner <lukas@wunner.de>2020-05-15 17:58:03 +0200
committerMark Brown <broonie@kernel.org>2020-05-20 15:16:12 +0100
commitb9dd3f6d417258ad0beeb292a1bc74200149f15d (patch)
treea5fc842ca454ab98415b26a8c987453f48911637 /drivers/spi/spi-bcm2835aux.c
parent9dd277ff92d06f6aa95b39936ad83981d781f49b (diff)
spi: bcm2835aux: Fix controller unregister order
The BCM2835aux SPI driver uses devm_spi_register_master() on bind. As a consequence, on unbind, __device_release_driver() first invokes bcm2835aux_spi_remove() before unregistering the SPI controller via devres_release_all(). This order is incorrect: bcm2835aux_spi_remove() turns off the SPI controller, including its interrupts and clock. The SPI controller is thus no longer usable. When the SPI controller is subsequently unregistered, it unbinds all its slave devices. If their drivers need to access the SPI bus, e.g. to quiesce their interrupts, unbinding will fail. As a rule, devm_spi_register_master() must not be used if the ->remove() hook performs teardown steps which shall be performed after unbinding of slaves. Fix by using the non-devm variant spi_register_master(). Note that the struct spi_master as well as the driver-private data are not freed until after bcm2835aux_spi_remove() has finished, so accessing them is safe. Fixes: 1ea29b39f4c8 ("spi: bcm2835aux: add bcm2835 auxiliary spi device driver") Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: stable@vger.kernel.org # v4.4+ Cc: Martin Sperl <kernel@martin.sperl.org> Link: https://lore.kernel.org/r/32f27f4d8242e4d75f9a53f7e8f1f77483b08669.1589557526.git.lukas@wunner.de Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-bcm2835aux.c')
-rw-r--r--drivers/spi/spi-bcm2835aux.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/spi/spi-bcm2835aux.c b/drivers/spi/spi-bcm2835aux.c
index a2162ff56a12..c331efd6e86b 100644
--- a/drivers/spi/spi-bcm2835aux.c
+++ b/drivers/spi/spi-bcm2835aux.c
@@ -569,7 +569,7 @@ static int bcm2835aux_spi_probe(struct platform_device *pdev)
goto out_clk_disable;
}
- err = devm_spi_register_master(&pdev->dev, master);
+ err = spi_register_master(master);
if (err) {
dev_err(&pdev->dev, "could not register SPI master: %d\n", err);
goto out_clk_disable;
@@ -593,6 +593,8 @@ static int bcm2835aux_spi_remove(struct platform_device *pdev)
bcm2835aux_debugfs_remove(bs);
+ spi_unregister_master(master);
+
bcm2835aux_spi_reset_hw(bs);
/* disable the HW block by releasing the clock */