diff mbox series

[1/3] xhci: also avoid the XHCI_ZERO_64B_REGS quirk with a passthrough iommu

Message ID 20230330143056.1390020-2-mathias.nyman@linux.intel.com (mailing list archive)
State Superseded
Commit ecaa4902439298f6b0e29f47424a86b310a9ff4f
Headers show
Series xhci fixes for usb-linus | expand

Commit Message

Mathias Nyman March 30, 2023, 2:30 p.m. UTC 
From: D Scott Phillips <scott@os.amperecomputing.com>

Previously the quirk was skipped when no iommu was present. The same
rationale for skipping the quirk also applies in the iommu.passthrough=1
case.

Skip applying the XHCI_ZERO_64B_REGS quirk if the device's iommu domain is
passthrough.

Fixes: 12de0a35c996 ("xhci: Add quirk to zero 64bit registers on Renesas PCIe controllers")
Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com>
Acked-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Comments

Greg Kroah-Hartman March 30, 2023, 2:40 p.m. UTC | #1 
On Thu, Mar 30, 2023 at 05:30:54PM +0300, Mathias Nyman wrote:
> From: D Scott Phillips <scott@os.amperecomputing.com>
> 
> Previously the quirk was skipped when no iommu was present. The same
> rationale for skipping the quirk also applies in the iommu.passthrough=1
> case.
> 
> Skip applying the XHCI_ZERO_64B_REGS quirk if the device's iommu domain is
> passthrough.
> 
> Fixes: 12de0a35c996 ("xhci: Add quirk to zero 64bit registers on Renesas PCIe controllers")

Why not also for stable?

thanks,

greg k-h
Mathias Nyman March 31, 2023, 7:35 a.m. UTC | #2 
On 30.3.2023 17.40, Greg KH wrote:
> On Thu, Mar 30, 2023 at 05:30:54PM +0300, Mathias Nyman wrote:
>> From: D Scott Phillips <scott@os.amperecomputing.com>
>>
>> Previously the quirk was skipped when no iommu was present. The same
>> rationale for skipping the quirk also applies in the iommu.passthrough=1
>> case.
>>
>> Skip applying the XHCI_ZERO_64B_REGS quirk if the device's iommu domain is
>> passthrough.
>>
>> Fixes: 12de0a35c996 ("xhci: Add quirk to zero 64bit registers on Renesas PCIe controllers")
> 
> Why not also for stable?

Ah, yes, this should go to stable as well.

Thanks
Mathias
Greg Kroah-Hartman March 31, 2023, 7:40 a.m. UTC | #3 
On Fri, Mar 31, 2023 at 10:35:07AM +0300, Mathias Nyman wrote:
> On 30.3.2023 17.40, Greg KH wrote:
> > On Thu, Mar 30, 2023 at 05:30:54PM +0300, Mathias Nyman wrote:
> > > From: D Scott Phillips <scott@os.amperecomputing.com>
> > > 
> > > Previously the quirk was skipped when no iommu was present. The same
> > > rationale for skipping the quirk also applies in the iommu.passthrough=1
> > > case.
> > > 
> > > Skip applying the XHCI_ZERO_64B_REGS quirk if the device's iommu domain is
> > > passthrough.
> > > 
> > > Fixes: 12de0a35c996 ("xhci: Add quirk to zero 64bit registers on Renesas PCIe controllers")
> > 
> > Why not also for stable?
> 
> Ah, yes, this should go to stable as well.

Thanks for confirming these, as you noticed, all are applied to my tree
now.

greg k-h
diff mbox series

Patch

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 6183ce8574b1..bdb6dd819a3b 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -9,6 +9,7 @@ 
  */
 
 #include <linux/pci.h>
+#include <linux/iommu.h>
 #include <linux/iopoll.h>
 #include <linux/irq.h>
 #include <linux/log2.h>
@@ -228,6 +229,7 @@  int xhci_reset(struct xhci_hcd *xhci, u64 timeout_us)
 static void xhci_zero_64b_regs(struct xhci_hcd *xhci)
 {
 	struct device *dev = xhci_to_hcd(xhci)->self.sysdev;
+	struct iommu_domain *domain;
 	int err, i;
 	u64 val;
 	u32 intrs;
@@ -246,7 +248,9 @@  static void xhci_zero_64b_regs(struct xhci_hcd *xhci)
 	 * an iommu. Doing anything when there is no iommu is definitely
 	 * unsafe...
 	 */
-	if (!(xhci->quirks & XHCI_ZERO_64B_REGS) || !device_iommu_mapped(dev))
+	domain = iommu_get_domain_for_dev(dev);
+	if (!(xhci->quirks & XHCI_ZERO_64B_REGS) || !domain ||
+	    domain->type == IOMMU_DOMAIN_IDENTITY)
 		return;
 
 	xhci_info(xhci, "Zeroing 64bit base registers, expecting fault\n");