[PATCH 0/4] spi: cadence: runtime PM fixes

[PATCH 0/4] spi: cadence: runtime PM fixes

[Johan Hovold]

This series fixes some runtime PM related issues in the cadence driver.

Included is also a couple of related cleanups.

Johan



Johan Hovold (4):
  spi: cadence: fix unclocked access on unbind
  spi: cadence: fix clock imbalance on probe failure
  spi: cadence: rename probe error labels
  spi: cadence: clean up probe return value

 drivers/spi/spi-cadence.c | 37 ++++++++++++++++++++++++-------------
 1 file changed, 24 insertions(+), 13 deletions(-)

-- 
2.52.0

[PATCH 1/4] spi: cadence: fix unclocked access on unbind

[Johan Hovold]

Make sure that the controller is runtime resumed before disabling it
during driver unbind to avoid unclocked register access and unbalanced
clock disable.

Also restore the autosuspend setting.

This issue was flagged by Sashiko when reviewing a controller
deregistration fix.

Fixes: d36ccd9f7ea4 ("spi: cadence: Runtime pm adaptation")
Cc: stable@vger.kernel.org	# 4.7
Cc: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://sashiko.dev/#/patchset/20260414134319.978196-1-johan%40kernel.org?part=1
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/spi/spi-cadence.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c
index 08d7dabe818d..bf4a7cf6b142 100644
--- a/drivers/spi/spi-cadence.c
+++ b/drivers/spi/spi-cadence.c
@@ -776,16 +776,23 @@ static void cdns_spi_remove(struct platform_device *pdev)
 {
 	struct spi_controller *ctlr = platform_get_drvdata(pdev);
 	struct cdns_spi *xspi = spi_controller_get_devdata(ctlr);
+	int ret = 0;
+
+	if (!spi_controller_is_target(ctlr))
+		ret = pm_runtime_get_sync(&pdev->dev);
 
 	spi_controller_get(ctlr);
 
 	spi_unregister_controller(ctlr);
 
-	cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE);
+	if (ret >= 0)
+		cdns_spi_write(xspi, CDNS_SPI_ER, CDNS_SPI_ER_DISABLE);
 
 	if (!spi_controller_is_target(ctlr)) {
 		pm_runtime_disable(&pdev->dev);
 		pm_runtime_set_suspended(&pdev->dev);
+		pm_runtime_put_noidle(&pdev->dev);
+		pm_runtime_dont_use_autosuspend(&pdev->dev);
 	}
 
 	spi_controller_put(ctlr);
-- 
2.52.0

[PATCH 2/4] spi: cadence: fix clock imbalance on probe failure

[Johan Hovold]

Make sure that the controller is active before disabling clocks on probe
failure to avoid unbalanced clock disable.

Also drop the usage count before returning (so that the controller can
be suspended after a probe deferral) and restore the autosuspend
setting.

Fixes: d36ccd9f7ea4 ("spi: cadence: Runtime pm adaptation")
Cc: stable@vger.kernel.org	# 4.7
Cc: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/spi/spi-cadence.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c
index bf4a7cf6b142..891e2ba36958 100644
--- a/drivers/spi/spi-cadence.c
+++ b/drivers/spi/spi-cadence.c
@@ -741,7 +741,6 @@ static int cdns_spi_probe(struct platform_device *pdev)
 		/* Set to default valid value */
 		ctlr->max_speed_hz = xspi->clk_rate / 4;
 		xspi->speed_hz = ctlr->max_speed_hz;
-		pm_runtime_put_autosuspend(&pdev->dev);
 	} else {
 		ctlr->mode_bits |= SPI_NO_CS;
 		ctlr->target_abort = cdns_target_abort;
@@ -752,12 +751,17 @@ static int cdns_spi_probe(struct platform_device *pdev)
 		goto clk_dis_all;
 	}
 
+	if (!spi_controller_is_target(ctlr))
+		pm_runtime_put_autosuspend(&pdev->dev);
+
 	return ret;
 
 clk_dis_all:
 	if (!spi_controller_is_target(ctlr)) {
 		pm_runtime_disable(&pdev->dev);
 		pm_runtime_set_suspended(&pdev->dev);
+		pm_runtime_put_noidle(&pdev->dev);
+		pm_runtime_dont_use_autosuspend(&pdev->dev);
 	}
 remove_ctlr:
 	spi_controller_put(ctlr);
-- 
2.52.0

[PATCH 3/4] spi: cadence: rename probe error labels

[Johan Hovold]

The "clk_dis_all" error label is not used to disable clocks since commit
f64b1600f92e ("spi: spi-cadence: Use helper function
devm_clk_get_enabled()").

Similarly, "remove_ctlr" drops a reference rather than deregisters the
controller.

Rename the labels after what they do.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/spi/spi-cadence.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c
index 891e2ba36958..f27586151ca9 100644
--- a/drivers/spi/spi-cadence.c
+++ b/drivers/spi/spi-cadence.c
@@ -656,21 +656,21 @@ static int cdns_spi_probe(struct platform_device *pdev)
 	xspi->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(xspi->regs)) {
 		ret = PTR_ERR(xspi->regs);
-		goto remove_ctlr;
+		goto err_put_ctlr;
 	}
 
 	xspi->pclk = devm_clk_get_enabled(&pdev->dev, "pclk");
 	if (IS_ERR(xspi->pclk)) {
 		dev_err(&pdev->dev, "pclk clock not found.\n");
 		ret = PTR_ERR(xspi->pclk);
-		goto remove_ctlr;
+		goto err_put_ctlr;
 	}
 
 	xspi->rstc = devm_reset_control_get_optional_exclusive(&pdev->dev, "spi");
 	if (IS_ERR(xspi->rstc)) {
 		ret = dev_err_probe(&pdev->dev, PTR_ERR(xspi->rstc),
 				    "Cannot get SPI reset.\n");
-		goto remove_ctlr;
+		goto err_put_ctlr;
 	}
 
 	reset_control_assert(xspi->rstc);
@@ -680,7 +680,7 @@ static int cdns_spi_probe(struct platform_device *pdev)
 	if (IS_ERR(xspi->ref_clk)) {
 		dev_err(&pdev->dev, "ref_clk clock not found.\n");
 		ret = PTR_ERR(xspi->ref_clk);
-		goto remove_ctlr;
+		goto err_put_ctlr;
 	}
 
 	if (!spi_controller_is_target(ctlr)) {
@@ -710,7 +710,7 @@ static int cdns_spi_probe(struct platform_device *pdev)
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0) {
 		ret = irq;
-		goto clk_dis_all;
+		goto err_disable_rpm;
 	}
 
 	ret = devm_request_irq(&pdev->dev, irq, cdns_spi_irq,
@@ -718,7 +718,7 @@ static int cdns_spi_probe(struct platform_device *pdev)
 	if (ret != 0) {
 		ret = -ENXIO;
 		dev_err(&pdev->dev, "request_irq failed\n");
-		goto clk_dis_all;
+		goto err_disable_rpm;
 	}
 
 	ctlr->use_gpio_descriptors = true;
@@ -748,7 +748,7 @@ static int cdns_spi_probe(struct platform_device *pdev)
 	ret = spi_register_controller(ctlr);
 	if (ret) {
 		dev_err(&pdev->dev, "spi_register_controller failed\n");
-		goto clk_dis_all;
+		goto err_disable_rpm;
 	}
 
 	if (!spi_controller_is_target(ctlr))
@@ -756,14 +756,14 @@ static int cdns_spi_probe(struct platform_device *pdev)
 
 	return ret;
 
-clk_dis_all:
+err_disable_rpm:
 	if (!spi_controller_is_target(ctlr)) {
 		pm_runtime_disable(&pdev->dev);
 		pm_runtime_set_suspended(&pdev->dev);
 		pm_runtime_put_noidle(&pdev->dev);
 		pm_runtime_dont_use_autosuspend(&pdev->dev);
 	}
-remove_ctlr:
+err_put_ctlr:
 	spi_controller_put(ctlr);
 	return ret;
 }
-- 
2.52.0

[PATCH 4/4] spi: cadence: clean up probe return value

[Johan Hovold]

Drop the redundant initialisation and return explicit zero on successful
probe to make the code more readable.

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/spi/spi-cadence.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-cadence.c b/drivers/spi/spi-cadence.c
index f27586151ca9..d108e89fda22 100644
--- a/drivers/spi/spi-cadence.c
+++ b/drivers/spi/spi-cadence.c
@@ -635,7 +635,7 @@ static int cdns_target_abort(struct spi_controller *ctlr)
  */
 static int cdns_spi_probe(struct platform_device *pdev)
 {
-	int ret = 0, irq;
+	int ret, irq;
 	struct spi_controller *ctlr;
 	struct cdns_spi *xspi;
 	u32 num_cs;
@@ -754,7 +754,7 @@ static int cdns_spi_probe(struct platform_device *pdev)
 	if (!spi_controller_is_target(ctlr))
 		pm_runtime_put_autosuspend(&pdev->dev);
 
-	return ret;
+	return 0;
 
 err_disable_rpm:
 	if (!spi_controller_is_target(ctlr)) {
-- 
2.52.0