Add a list of EHCI devices that are known to work or not to work with MSI.
For unknown devices, MSI is disabled by default.
The new enable_msi module parameter allows to override this decision.
NOT-yet-signed-off-by: Clemens Ladisch <clemens@xxxxxxxxxx>
---
drivers/usb/host/ehci-pci.c | 59 +++++++++++++++++++++++++++++++-----
1 files changed, 51 insertions(+), 8 deletions(-)
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -22,8 +22,56 @@
#error "This file is PCI bus glue. CONFIG_PCI must be defined."
#endif
+static int enable_msi = -1;
+module_param(enable_msi, int, 0444);
+MODULE_PARM_DESC(enable_msi,
+ "enable message-signaled interrupts, 0=no, 1=yes, -1=auto");
+
/*-------------------------------------------------------------------------*/
+static u8 get_ati_southbridge_revision(void)
+{
+ struct pci_dev *p_smbus;
+ u8 rev;
+
+ p_smbus = pci_get_device(PCI_VENDOR_ID_ATI,
+ PCI_DEVICE_ID_ATI_SBX00_SMBUS, NULL);
+ if (!p_smbus)
+ return 0;
+ rev = p_smbus->revision;
+ pci_dev_put(p_smbus);
+ return rev;
+}
+
+/* called before chip (interrupt) initialization */
+static bool ehci_pci_msi_allowed(struct usb_hcd *hcd)
+{
+ struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
+
+ if (!enable_msi)
+ return false;
+ if (enable_msi > 0)
+ return true;
+
+ switch (pdev->vendor) {
+ case PCI_VENDOR_ID_INTEL:
+ return true;
+ case PCI_VENDOR_ID_ATI:
+ switch (pdev->device) {
+ case 0x4396: /* ATI SB7x0: MSI works in rev A14 or later */
+ return get_ati_southbridge_revision() >= 0x3c;
+ }
+ break;
+ case PCI_VENDOR_ID_AL:
+ switch (pdev->device) {
+ case 0x5239: /* ULi M1575 */
+ return false;
+ }
+ break;
+ }
+ return false;
+}
+
/* called after powerup, by probe or system-pm "wakeup" */
static int ehci_pci_reinit(struct ehci_hcd *ehci, struct pci_dev *pdev)
{
@@ -46,7 +94,6 @@ static int ehci_pci_setup(struct usb_hcd
{
struct ehci_hcd *ehci = hcd_to_ehci(hcd);
struct pci_dev *pdev = to_pci_dev(hcd->self.controller);
- struct pci_dev *p_smbus;
u8 rev;
u32 temp;
int retval;
@@ -163,12 +210,7 @@ static int ehci_pci_setup(struct usb_hcd
* which causes usb devices lose response in some cases.
*/
if ((pdev->device == 0x4386) || (pdev->device == 0x4396)) {
- p_smbus = pci_get_device(PCI_VENDOR_ID_ATI,
- PCI_DEVICE_ID_ATI_SBX00_SMBUS,
- NULL);
- if (!p_smbus)
- break;
- rev = p_smbus->revision;
+ rev = get_ati_southbridge_revision();
if ((pdev->device == 0x4386) || (rev == 0x3a)
|| (rev == 0x3b)) {
u8 tmp;
@@ -177,7 +219,6 @@ static int ehci_pci_setup(struct usb_hcd
pci_read_config_byte(pdev, 0x53, &tmp);
pci_write_config_byte(pdev, 0x53, tmp | (1<<3));
}
- pci_dev_put(p_smbus);
}
break;
}
@@ -372,6 +413,8 @@ static const struct hc_driver ehci_pci_h
.irq = ehci_irq,
.flags = HCD_MEMORY | HCD_USB2,
+ .is_pci_msi_allowed = ehci_pci_msi_allowed,
+
/*
* basic lifecycle operations
*/
--
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