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usb: xhci: Restore xhci_pci support for Renesas HCs

PATCH Superseded Michal Pecio 3 participants 5 messages Jan 27, 2025 – Feb 3, 2025

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#0 lore raw

PATCH 1/1 usb: xhci: Restore xhci_pci support for Renesas HCs

Some Renesas HCs require firmware upload to work, this is handled by the xhci_pci_renesas driver. Other variants of those chips load firmware from onboard flash and can work with xhci_pci alone.

A refactor merged in v6.12 broke the latter configuration and users are finding their hardware not working after upgrading and need to enable the firmware loader which isn't really necessary on their systems.

Let xhci_pci work with those chips as before when the firmware loader is disabled by kernel configuration.

Fixes 25f51b76f90f ("xhci-pci: Make xhci-pci-renesas a proper modular driver")
---
 drivers/usb/host/xhci-pci.c | 4 ++++
 1 file changed, 4 insertions(+)
drivers/usb/host/xhci-pci.c +4 -0
index 5a5f0b2dba4d..3d08d6527b1d 100644
@@ -657,17 +657,21 @@ int xhci_pci_common_probe(struct pci_dev *dev, const struct pci_device_id *id)
 }
 EXPORT_SYMBOL_NS_GPL(xhci_pci_common_probe, "xhci");
 
+#if IS_ENABLED(CONFIG_USB_XHCI_PCI_RENESAS)
 static const struct pci_device_id pci_ids_reject[] = {
 	/* handled by xhci-pci-renesas */
 	{ PCI_DEVICE(PCI_VENDOR_ID_RENESAS, 0x0014) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_RENESAS, 0x0015) },
 	{ /* end: all zeroes */ }
 };
+#endif
 
 static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
+#if IS_ENABLED(CONFIG_USB_XHCI_PCI_RENESAS)
 	if (pci_match_id(pci_ids_reject, dev))
 		return -ENODEV;
+#endif
 
 	return xhci_pci_common_probe(dev, id);
 }
Signature · 1 line
2.48.1
#1 lore raw
Quoted 7 lines · Michal Pecio

Some Renesas HCs require firmware upload to work, this is handled by the xhci_pci_renesas driver. Other variants of those chips load firmware from onboard flash and can work with xhci_pci alone.

A refactor merged in v6.12 broke the latter configuration and users are finding their hardware not working after upgrading and need to enable the firmware loader which isn't really necessary on their systems.

Why isn't it necessary? Those chips want firmware to be uploaded, and if the driver doesn't need it, it should be able to handle it if it is not present.

Quoted 25 lines

Let xhci_pci work with those chips as before when the firmware loader is disabled by kernel configuration.

Fixes 25f51b76f90f ("xhci-pci: Make xhci-pci-renesas a proper modular driver")
---
 drivers/usb/host/xhci-pci.c | 4 ++++
 1 file changed, 4 insertions(+)
drivers/usb/host/xhci-pci.c +1 -0
index 5a5f0b2dba4d..3d08d6527b1d 100644
@@ -657,17 +657,21 @@ int xhci_pci_common_probe(struct pci_dev *dev, const struct pci_device_id *id)
 }
 EXPORT_SYMBOL_NS_GPL(xhci_pci_common_probe, "xhci");
 
+#if IS_ENABLED(CONFIG_USB_XHCI_PCI_RENESAS)
 static const struct pci_device_id pci_ids_reject[] = {
 	/* handled by xhci-pci-renesas */
 	{ PCI_DEVICE(PCI_VENDOR_ID_RENESAS, 0x0014) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_RENESAS, 0x0015) },

drivers/usb/host/xhci-pci.c int xhci_pci_common_probe(struct pci_dev *dev, const struct pci_device_id *id) · line 674

Quoted 10 lines
drivers/usb/host/xhci-pci.c +3 -0
 	{ /* end: all zeroes */ }
 };
+#endif
 
 static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
+#if IS_ENABLED(CONFIG_USB_XHCI_PCI_RENESAS)
 	if (pci_match_id(pci_ids_reject, dev))
 		return -ENODEV;
+#endif

No, please don't put #ifdef in .c files if at all preventable.

If the firmware isn't there, then the driver should be fixed to keep on working if it determines loading it is not needed. This type of check should not be needed in the xhci-pci.c file.

thanks,

greg k-h

#2 lore raw
Quoted 5 lines · Greg Kroah-Hartman
Quoted 4 lines · Michal Pecio

Some Renesas HCs require firmware upload to work, this is handled by the xhci_pci_renesas driver. Other variants of those chips load firmware from onboard flash and can work with xhci_pci alone.

Quoted 8 lines
Quoted 4 lines

A refactor merged in v6.12 broke the latter configuration and users are finding their hardware not working after upgrading and need to enable the firmware loader which isn't really necessary on their systems.

Why isn't it necessary? Those chips want firmware to be uploaded, and if the driver doesn't need it, it should be able to handle it if it is not present.

Because their chips have already loaded themselves from attached SPI flash, so they are ready to use with xhci_pci like any other HC.

The FW isn't optional, we just usually don't need to load it. And FW for those chips is obscure and not redistributable AFAIK, so people have little reason to enable xhci_pci_renesas if their board has ROM and works without it. It is 'N' by default.

Quoted 1 line

No, please don't put #ifdef in .c files if at all preventable.

Hmm, I suppose I could replace the #ifdef with 'if (IS_ENABLED(...))' and leave the rest to dead code elimination if that's preferred.

Annoyingly, the code to be knocked out is in xhci-pci and it has to stay there to avoid runtime dependency on xhci-pci-renesas, which was the whole point of the refactor.

Quoted 3 lines

If the firmware isn't there, then the driver should be fixed to keep on working if it determines loading it is not needed. This type of check should not be needed in the xhci-pci.c file.

This is a check for kernel configuration, not for firmware. If the loader is disabled, we don't want to reject those chips expecting them to be taken care of by the loader, because that is not going to happen.

Regards,
Michal

#3 lore raw

PATCH v2 1/1 usb: xhci: Restore xhci_pci support for Renesas HCs

In reply to Michal Pecio

Some Renesas HCs require firmware upload to work, this is handled by the xhci_pci_renesas driver. Other variants of those chips load firmware from a SPI flash and are ready to work with xhci_pci alone.

A refactor merged in v6.12 broke the latter configuration so that users are finding their hardware ignored by the normal driver and are forced to enable the firmware loader which isn't really necessary on their systems.

Let xhci_pci work with those chips as before when the firmware loader is disabled by kernel configuration.

Fixes 25f51b76f90f ("xhci-pci: Make xhci-pci-renesas a proper modular driver")

---

new in v2:
- changed #ifdef CONFIG_XXX to if (IS_ENABLED(CONFIG_XXX))
- renamed the PCI IDs table to clarify code intent
- small commit message improvements

 drivers/usb/host/xhci-pci.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
drivers/usb/host/xhci-pci.c +4 -3
index 5a5f0b2dba4d..54460d11f7ee 100644
@@ -657,8 +657,8 @@ int xhci_pci_common_probe(struct pci_dev *dev, const struct pci_device_id *id)
 }
 EXPORT_SYMBOL_NS_GPL(xhci_pci_common_probe, "xhci");
 
-static const struct pci_device_id pci_ids_reject[] = {
-	/* handled by xhci-pci-renesas */
+/* handled by xhci-pci-renesas if enabled */
+static const struct pci_device_id pci_ids_renesas[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_RENESAS, 0x0014) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_RENESAS, 0x0015) },
 	{ /* end: all zeroes */ }
@@ -666,7 +666,8 @@ static const struct pci_device_id pci_ids_reject[] = {
 
 static int xhci_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
-	if (pci_match_id(pci_ids_reject, dev))
+	if (IS_ENABLED(CONFIG_USB_XHCI_PCI_RENESAS) &&
+			pci_match_id(pci_ids_renesas, dev))
 		return -ENODEV;
 
 	return xhci_pci_common_probe(dev, id);
Signature · 1 line
2.48.1
Tested-by on v2 1/1
#4 lore raw
Quoted 8 lines · Michal Pecio

Some Renesas HCs require firmware upload to work, this is handled by the xhci_pci_renesas driver. Other variants of those chips load firmware from a SPI flash and are ready to work with xhci_pci alone.

A refactor merged in v6.12 broke the latter configuration so that users are finding their hardware ignored by the normal driver and are forced to enable the firmware loader which isn't really necessary on their systems.

Quoted 8 lines

Let xhci_pci work with those chips as before when the firmware loader is disabled by kernel configuration.

Fixes 25f51b76f90f ("xhci-pci: Make xhci-pci-renesas a proper modular driver")

Can confirm that this patch restores the old behavior, where xhci-pci supported the Renesas controllers when an external SPI flash is attached. I've tested with a PCIe extension card on arm64 and x86 as well as with a arm64 (Raspberry CM4) based Revolution Pi Connect 4.

Thanks!

Nicolai

Quoted 38 lines

---

new in v2:
- changed #ifdef CONFIG_XXX to if (IS_ENABLED(CONFIG_XXX))
- renamed the PCI IDs table to clarify code intent
- small commit message improvements

 drivers/usb/host/xhci-pci.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)
drivers/usb/host/xhci-pci.c +2 -2
index 5a5f0b2dba4d..54460d11f7ee 100644
@@ -657,8 +657,8 @@ int xhci_pci_common_probe(struct pci_dev *dev, 
 const struct pci_device_id *id)
 }
 EXPORT_SYMBOL_NS_GPL(xhci_pci_common_probe, "xhci");
 
-static const struct pci_device_id pci_ids_reject[] = {
-	/* handled by xhci-pci-renesas */
+/* handled by xhci-pci-renesas if enabled */
+static const struct pci_device_id pci_ids_renesas[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_RENESAS, 0x0014) },
 	{ PCI_DEVICE(PCI_VENDOR_ID_RENESAS, 0x0015) },
drivers/usb/host/xhci-pci.c +2 -1
 	{ /* end: all zeroes */ }
@@ -666,7 +666,8 @@ static const struct pci_device_id pci_ids_reject[] 
 = {
 
 static int xhci_pci_probe(struct pci_dev *dev, const struct 
 pci_device_id *id)
 {
-	if (pci_match_id(pci_ids_reject, dev))
+	if (IS_ENABLED(CONFIG_USB_XHCI_PCI_RENESAS) &&
+			pci_match_id(pci_ids_renesas, dev))
 		return -ENODEV;

return xhci_pci_common_probe(dev, id);