[PATCH 0/5] ata: sata_dwc_460ex: cleanups and interrupt ordering fix

[PATCH 0/5] ata: sata_dwc_460ex: cleanups and interrupt ordering fix

[Rosen Penev]

This series modernizes the sata_dwc_460ex driver by replacing legacy OF
APIs with their modern device-property and platform-device counterparts,
converting old DMA resource teardown to devm-managed cleanup, fixing a
latent interrupt-ordering bug, and dropping a redundant stack copy of
port_info.

Patch 4 fixes a real issue: sata_dwc_enable_interrupts() was called
before the IRQ handler was registered, so a probe failure or an
asserted interrupt could trigger an unhandled irq storm.

Rosen Penev (5):
  ata: sata_dwc_460ex: use device_property_present()
  ata: sata_dwc_460ex: use platform_get_irq()
  ata: sata_dwc_460ex: use devm for old DMA resource lifetime management
  ata: sata_dwc_460ex: enable SATA interrupts only after IRQ handler is
    registered
  ata: sata_dwc_460ex: drop redundant struct copy of port_info

 drivers/ata/sata_dwc_460ex.c | 66 +++++++++++++++---------------------
 1 file changed, 28 insertions(+), 38 deletions(-)

-- 
2.55.0

[PATCH 1/5] ata: sata_dwc_460ex: use device_property_present()

[Rosen Penev]

There's no need to use np here when dev is enough. Follows the similar
pattern elsewhere where of APIs are replaced with device ones,
especially when using platform_device.

Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/ata/sata_dwc_460ex.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/ata/sata_dwc_460ex.c b/drivers/ata/sata_dwc_460ex.c
index 4fc22ce4bd9a..2bcb3ac5ae21 100644
--- a/drivers/ata/sata_dwc_460ex.c
+++ b/drivers/ata/sata_dwc_460ex.c
@@ -1180,7 +1180,7 @@ static int sata_dwc_probe(struct platform_device *ofdev)
 	}
 
 #ifdef CONFIG_SATA_DWC_OLD_DMA
-	if (!of_property_present(np, "dmas")) {
+	if (!device_property_present(dev, "dmas")) {
 		err = sata_dwc_dma_init_old(ofdev, hsdev);
 		if (err)
 			return err;
-- 
2.55.0

[PATCH 2/5] ata: sata_dwc_460ex: use platform_get_irq()

[Rosen Penev]

Replace irq_of_parse_and_map() with platform_get_irq() in both
sata_dwc_dma_init_old() and sata_dwc_probe(). This is the preferred
way to obtain IRQs for platform devices and provides better error
reporting.  Remove the now-unnecessary #include <linux/of_irq.h>.

irq_of_parse_and_map() requires irq_dispose_mapping(), which is missing.

Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/ata/sata_dwc_460ex.c | 19 ++++++-------------
 1 file changed, 6 insertions(+), 13 deletions(-)

diff --git a/drivers/ata/sata_dwc_460ex.c b/drivers/ata/sata_dwc_460ex.c
index 2bcb3ac5ae21..215b5a65527d 100644
--- a/drivers/ata/sata_dwc_460ex.c
+++ b/drivers/ata/sata_dwc_460ex.c
@@ -19,7 +19,6 @@
 #include <linux/device.h>
 #include <linux/dmaengine.h>
 #include <linux/of.h>
-#include <linux/of_irq.h>
 #include <linux/platform_device.h>
 #include <linux/phy/phy.h>
 #include <linux/libata.h>
@@ -226,7 +225,6 @@ static int sata_dwc_dma_init_old(struct platform_device *pdev,
 				 struct sata_dwc_device *hsdev)
 {
 	struct device *dev = &pdev->dev;
-	struct device_node *np = dev->of_node;
 
 	hsdev->dma = devm_kzalloc(dev, sizeof(*hsdev->dma), GFP_KERNEL);
 	if (!hsdev->dma)
@@ -236,11 +234,9 @@ static int sata_dwc_dma_init_old(struct platform_device *pdev,
 	hsdev->dma->id = pdev->id;
 
 	/* Get SATA DMA interrupt number */
-	hsdev->dma->irq = irq_of_parse_and_map(np, 1);
-	if (!hsdev->dma->irq) {
-		dev_err(dev, "no SATA DMA irq\n");
-		return -ENODEV;
-	}
+	hsdev->dma->irq = platform_get_irq(pdev, 1);
+	if (hsdev->dma->irq < 0)
+		return hsdev->dma->irq;
 
 	/* Get physical SATA DMA register base address */
 	hsdev->dma->regs = devm_platform_ioremap_resource(pdev, 1);
@@ -1126,7 +1122,6 @@ static const struct ata_port_info sata_dwc_port_info[] = {
 static int sata_dwc_probe(struct platform_device *ofdev)
 {
 	struct device *dev = &ofdev->dev;
-	struct device_node *np = dev->of_node;
 	struct sata_dwc_device *hsdev;
 	u32 idr, versionr;
 	char *ver = (char *)&versionr;
@@ -1173,11 +1168,9 @@ static int sata_dwc_probe(struct platform_device *ofdev)
 	sata_dwc_enable_interrupts(hsdev);
 
 	/* Get SATA interrupt number */
-	irq = irq_of_parse_and_map(np, 0);
-	if (!irq) {
-		dev_err(dev, "no SATA DMA irq\n");
-		return -ENODEV;
-	}
+	irq = platform_get_irq(ofdev, 0);
+	if (irq < 0)
+		return irq;
 
 #ifdef CONFIG_SATA_DWC_OLD_DMA
 	if (!device_property_present(dev, "dmas")) {
-- 
2.55.0

[PATCH 3/5] ata: sata_dwc_460ex: use devm for old DMA resource lifetime management

[Rosen Penev]

Convert sata_dwc_dma_exit_old() to a devm action callback and register
it via devm_add_action_or_reset() after dw_dma_probe() succeeds.  This
lets the devm framework handle DMA controller teardown automatically on
probe failure and driver removal.

As a result the probe function can use plain return-on-error for all
failure paths — the dma_initialized flag, the goto labels, and the
explicit sata_dwc_dma_exit_old() call in sata_dwc_remove() are all
eliminated.

Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/ata/sata_dwc_460ex.c | 36 +++++++++++++++++-------------------
 1 file changed, 17 insertions(+), 19 deletions(-)

diff --git a/drivers/ata/sata_dwc_460ex.c b/drivers/ata/sata_dwc_460ex.c
index 215b5a65527d..34d6d0534e30 100644
--- a/drivers/ata/sata_dwc_460ex.c
+++ b/drivers/ata/sata_dwc_460ex.c
@@ -221,10 +221,18 @@ static int sata_dwc_dma_get_channel_old(struct sata_dwc_device_port *hsdevp)
 	return 0;
 }
 
+static void sata_dwc_dma_exit_old(void *data)
+{
+	struct sata_dwc_device *hsdev = data;
+
+	dw_dma_remove(hsdev->dma);
+}
+
 static int sata_dwc_dma_init_old(struct platform_device *pdev,
 				 struct sata_dwc_device *hsdev)
 {
 	struct device *dev = &pdev->dev;
+	int err;
 
 	hsdev->dma = devm_kzalloc(dev, sizeof(*hsdev->dma), GFP_KERNEL);
 	if (!hsdev->dma)
@@ -244,15 +252,11 @@ static int sata_dwc_dma_init_old(struct platform_device *pdev,
 		return PTR_ERR(hsdev->dma->regs);
 
 	/* Initialize AHB DMAC */
-	return dw_dma_probe(hsdev->dma);
-}
-
-static void sata_dwc_dma_exit_old(struct sata_dwc_device *hsdev)
-{
-	if (!hsdev->dma)
-		return;
+	err = dw_dma_probe(hsdev->dma);
+	if (err)
+		return err;
 
-	dw_dma_remove(hsdev->dma);
+	return devm_add_action_or_reset(dev, sata_dwc_dma_exit_old, hsdev);
 }
 
 #endif
@@ -1186,7 +1190,7 @@ static int sata_dwc_probe(struct platform_device *ofdev)
 
 	err = phy_init(hsdev->phy);
 	if (err)
-		goto error_out;
+		return err;
 
 	/*
 	 * Now, register with libATA core, this will also initiate the
@@ -1194,14 +1198,13 @@ static int sata_dwc_probe(struct platform_device *ofdev)
 	 * error_handler() to execute a dummy Softreset EH session
 	 */
 	err = ata_host_activate(host, irq, sata_dwc_isr, 0, &sata_dwc_sht);
-	if (err)
+	if (err) {
 		dev_err(dev, "failed to activate host");
+		phy_exit(hsdev->phy);
+		return err;
+	}
 
 	return 0;
-
-error_out:
-	phy_exit(hsdev->phy);
-	return err;
 }
 
 static void sata_dwc_remove(struct platform_device *ofdev)
@@ -1214,11 +1217,6 @@ static void sata_dwc_remove(struct platform_device *ofdev)
 
 	phy_exit(hsdev->phy);
 
-#ifdef CONFIG_SATA_DWC_OLD_DMA
-	/* Free SATA DMA resources */
-	sata_dwc_dma_exit_old(hsdev);
-#endif
-
 	dev_dbg(dev, "done\n");
 }
 
-- 
2.55.0

[PATCH 4/5] ata: sata_dwc_460ex: enable SATA interrupts only after IRQ handler is registered

[Rosen Penev]

sata_dwc_enable_interrupts() is called before platform_get_irq() and
ata_host_activate(), leaving the SATA controller's interrupt mask
enabled without a registered handler.  If a later step fails (irq
request, phy init, etc.) or if the controller asserts an interrupt
during probe, the irq line may fire with no handler, causing a
spurious interrupt storm.

Move sata_dwc_enable_interrupts() after ata_host_activate() so that
interrupts are only unmasked once the handler is registered and the
core is fully initialized.

Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/ata/sata_dwc_460ex.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/ata/sata_dwc_460ex.c b/drivers/ata/sata_dwc_460ex.c
index 34d6d0534e30..fb6042b9ac27 100644
--- a/drivers/ata/sata_dwc_460ex.c
+++ b/drivers/ata/sata_dwc_460ex.c
@@ -1168,9 +1168,6 @@ static int sata_dwc_probe(struct platform_device *ofdev)
 	/* Save dev for later use in dev_xxx() routines */
 	hsdev->dev = dev;
 
-	/* Enable SATA Interrupts */
-	sata_dwc_enable_interrupts(hsdev);
-
 	/* Get SATA interrupt number */
 	irq = platform_get_irq(ofdev, 0);
 	if (irq < 0)
@@ -1204,6 +1201,8 @@ static int sata_dwc_probe(struct platform_device *ofdev)
 		return err;
 	}
 
+	/* Enable SATA Interrupts */
+	sata_dwc_enable_interrupts(hsdev);
 	return 0;
 }
 
-- 
2.55.0

[PATCH 5/5] ata: sata_dwc_460ex: drop redundant struct copy of port_info

[Rosen Penev]

sata_dwc_port_info[0] was copied to a local auto variable before being
referenced via a pointer array.  The local copy is never modified, so
drop it and point ppi directly at the static data.  This saves ~104
bytes of stack and makes the const qualification consistent.

Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/ata/sata_dwc_460ex.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/ata/sata_dwc_460ex.c b/drivers/ata/sata_dwc_460ex.c
index fb6042b9ac27..af00acf155d4 100644
--- a/drivers/ata/sata_dwc_460ex.c
+++ b/drivers/ata/sata_dwc_460ex.c
@@ -1133,8 +1133,8 @@ static int sata_dwc_probe(struct platform_device *ofdev)
 	int err = 0;
 	int irq;
 	struct ata_host *host;
-	struct ata_port_info pi = sata_dwc_port_info[0];
-	const struct ata_port_info *ppi[] = { &pi, NULL };
+	const struct ata_port_info *pi = &sata_dwc_port_info[0];
+	const struct ata_port_info *ppi[] = { pi, NULL };
 	struct resource *res;
 
 	/* Allocate DWC SATA device */
-- 
2.55.0