Current PCI hcd driver will check and enable line IRQ first, if line
IRQ is no setting in BIOS, XHCI PCIe driver will exit. But infact, if
MSI can work for this HCD, this behavior will refuse a workable HCD.
This patch change the behavior. It skips the first line IRQ checking for
PCI XHCI HCD in usb-core, and try to enable MSI first, if the MSI out of
work, it is back to line IRQ at that time. And further more, trying MSI
first can avoid a unnecessary request/free irq for line IRQ for PCIe HCD.
Thanks for Sarah and Andiry's suggestion and review for this patch.
Signed-off-by: Alex Shi <alex.shi@xxxxxxxxx>
---
drivers/usb/core/hcd-pci.c | 3 ++-
drivers/usb/core/hcd.c | 7 +++++--
drivers/usb/host/xhci-pci.c | 3 ++-
drivers/usb/host/xhci.c | 28 ++++++++++++++--------------
include/linux/usb/hcd.h | 1 +
5 files changed, 24 insertions(+), 18 deletions(-)
diff --git a/drivers/usb/core/hcd-pci.c b/drivers/usb/core/hcd-pci.c
index a004db3..266ea2f 100644
--- a/drivers/usb/core/hcd-pci.c
+++ b/drivers/usb/core/hcd-pci.c
@@ -187,7 +187,8 @@ int usb_hcd_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
return -ENODEV;
dev->current_state = PCI_D0;
- if (!dev->irq) {
+ /* skip irq check if hcd wants MSI firstly. */
+ if (!(driver->flags & HCD_MSI_FIRST) && !dev->irq) {
dev_err(&dev->dev,
"Found HC with no IRQ. Check BIOS/PCI %s setup!\n",
pci_name(dev));
diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 13222d3..0a4f185 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -2466,8 +2466,11 @@ int usb_add_hcd(struct usb_hcd *hcd,
&& device_can_wakeup(&hcd->self.root_hub->dev))
dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
- /* enable irqs just before we start the controller */
- if (usb_hcd_is_primary_hcd(hcd)) {
+ /* enable irqs just before we start the controller, except MSI
+ * first try HCD. That will do it in following driver->start();
+ */
+ if (usb_hcd_is_primary_hcd(hcd) &&
+ !(hcd->driver->flags & HCD_MSI_FIRST)) {
retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
if (retval)
goto err_request_irq;
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index ef98b38..3283e62 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -243,7 +243,8 @@ static const struct hc_driver xhci_pci_hc_driver = {
* generic hardware linkage
*/
.irq = xhci_irq,
- .flags = HCD_MEMORY | HCD_USB3 | HCD_SHARED,
+ .flags = HCD_MEMORY | HCD_USB3 | HCD_SHARED |
+ HCD_MSI_FIRST,
/*
* basic lifecycle operations
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index a1afb7c..e385a55 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -331,26 +331,26 @@ static int xhci_try_enable_msi(struct usb_hcd *hcd)
struct pci_dev *pdev = to_pci_dev(xhci_to_hcd(xhci)->self.controller);
int ret;
+ hcd->irq = -1;
/*
* Some Fresco Logic host controllers advertise MSI, but fail to
* generate interrupts. Don't even try to enable MSI.
*/
- if (xhci->quirks & XHCI_BROKEN_MSI)
- return 0;
-
- /* unregister the legacy interrupt */
- if (hcd->irq)
- free_irq(hcd->irq, hcd);
- hcd->irq = -1;
+ if (!(xhci->quirks & XHCI_BROKEN_MSI)) {
+ ret = xhci_setup_msix(xhci);
+ if (ret)
+ /* fall back to msi*/
+ ret = xhci_setup_msi(xhci);
- ret = xhci_setup_msix(xhci);
- if (ret)
- /* fall back to msi*/
- ret = xhci_setup_msi(xhci);
+ if (!ret)
+ /* hcd->irq is -1, we have MSI */
+ return 0;
+ }
- if (!ret)
- /* hcd->irq is -1, we have MSI */
- return 0;
+ if (!pdev->irq) {
+ xhci_err(xhci, "No msi-x/msi found and no IRQ in BIOS\n");
+ return -EINVAL;
+ }
/* fall back to legacy interrupt*/
ret = request_irq(pdev->irq, &usb_hcd_irq, IRQF_SHARED,
diff --git a/include/linux/usb/hcd.h b/include/linux/usb/hcd.h
index 03354d5..ea1637b 100644
--- a/include/linux/usb/hcd.h
+++ b/include/linux/usb/hcd.h
@@ -212,6 +212,7 @@ struct hc_driver {
#define HCD_MEMORY 0x0001 /* HC regs use memory (else I/O) */
#define HCD_LOCAL_MEM 0x0002 /* HC needs local memory */
#define HCD_SHARED 0x0004 /* Two (or more) usb_hcds share HW */
+#define HCD_MSI_FIRST 0x0008 /* Try to get MSI first, PCI only */
#define HCD_USB11 0x0010 /* USB 1.1 */
#define HCD_USB2 0x0020 /* USB 2.0 */
#define HCD_USB3 0x0040 /* USB 3.0 */
--
1.6.3.3
--
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