[PATCH] drivers: spi: cadence-quadspi: Handle spi_unregister_master() in remove()

[PATCH] drivers: spi: cadence-quadspi: Handle spi_unregister_master() in remove()

[Vaishnav Achath]

Currently devres managed removal of the spi_controller happens after
removing the power domain of the host platform_device.While this
does not affect the clean removal of the controller, but affects
graceful removal of the child devices if the child  device removal
requires issuing commands over SPI.

Eg. flash device being soft reset to 1S-1S-1S mode before removal
so that on next probe operations in 1S-1S-1S mode is successful.

Failure is seen when `rmmod spi-cadence-quadspi` is performed:

root@j7-evm:~# rmmod spi_cadence_quadspi
[ 49.230996] cadence-qspi 47050000.spi: QSPI is still busy after 500ms timeout.
[ 49.238209] spi-nor spi1.0: operation failed with -110
[ 49.244457] spi-nor spi1.0: Software reset failed: -110

and on subsequent modprobe the OSPI flash probe fails as it
is in 8D-8D-8D mode since the previous soft reset did not happen.

root@j7-evm:~# modprobe spi_cadence_quadspi
[ 73.253536] spi-nor spi0.0: unrecognized JEDEC id bytes: ff ff ff ff ff ff
[ 73.260476] spi-nor: probe of spi0.0 failed with error -2

This commit adds necessary changes to perform spi_unregister_master()
in the host device remove() so that the child devices are gracefully
removed before the power domain is removed.

changes tested on J721E with mt35xu512aba flash.

Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com>
---
 drivers/spi/spi-cadence-quadspi.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c
index 19686fb47bb3..baf8559b553b 100644
--- a/drivers/spi/spi-cadence-quadspi.c
+++ b/drivers/spi/spi-cadence-quadspi.c
@@ -62,7 +62,7 @@ struct cqspi_flash_pdata {
 
 struct cqspi_st {
 	struct platform_device	*pdev;
-
+	struct spi_master	*master;
 	struct clk		*clk;
 	unsigned int		sclk;
 
@@ -1639,7 +1639,7 @@ static int cqspi_probe(struct platform_device *pdev)
 	int ret;
 	int irq;
 
-	master = spi_alloc_master(&pdev->dev, sizeof(*cqspi));
+	master = devm_spi_alloc_master(&pdev->dev, sizeof(*cqspi));
 	if (!master) {
 		dev_err(&pdev->dev, "spi_alloc_master failed\n");
 		return -ENOMEM;
@@ -1652,6 +1652,7 @@ static int cqspi_probe(struct platform_device *pdev)
 	cqspi = spi_master_get_devdata(master);
 
 	cqspi->pdev = pdev;
+	cqspi->master = master;
 	platform_set_drvdata(pdev, cqspi);
 
 	/* Obtain configuration from OF. */
@@ -1784,7 +1785,7 @@ static int cqspi_probe(struct platform_device *pdev)
 			goto probe_setup_failed;
 	}
 
-	ret = devm_spi_register_master(dev, master);
+	ret = spi_register_master(master);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to register SPI ctlr %d\n", ret);
 		goto probe_setup_failed;
@@ -1807,6 +1808,7 @@ static int cqspi_remove(struct platform_device *pdev)
 {
 	struct cqspi_st *cqspi = platform_get_drvdata(pdev);
 
+	spi_unregister_master(cqspi->master);
 	cqspi_controller_enable(cqspi, 0);
 
 	if (cqspi->rx_chan)
-- 
2.17.1

Re: [PATCH] drivers: spi: cadence-quadspi: Handle spi_unregister_master() in remove()

[Mark Brown]

On Wed, 11 May 2022 17:25:16 +0530, Vaishnav Achath wrote:
> Currently devres managed removal of the spi_controller happens after
> removing the power domain of the host platform_device.While this
> does not affect the clean removal of the controller, but affects
> graceful removal of the child devices if the child  device removal
> requires issuing commands over SPI.
> 
> Eg. flash device being soft reset to 1S-1S-1S mode before removal
> so that on next probe operations in 1S-1S-1S mode is successful.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] drivers: spi: cadence-quadspi: Handle spi_unregister_master() in remove()
      commit: 606e5d408184989f53028125e0cb5aa6713362d5

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark