5.10-stable patches

added patches:
	usb-ehci-prevent-missed-ehci-interrupts-with-edge-triggered-msi.patch

diff --git a/queue-5.10/series b/queue-5.10/series
index 27bf8caec18f2f213c227c1499e38d71163534ec..b9b4e57f339f41b3e78725ee8af893dee38f5714 100644 (file)
--- a/queue-5.10/series
+++ b/queue-5.10/series
@@ -161,3 +161,4 @@ bonding-fix-build-issue.patch
 skbuff-release-nfct-refcount-on-napi-stolen-or-re-used-skbs.patch
 documentation-fix-intiramfs-script-name.patch
 perf-inject-close-inject.output-on-exit.patch
+usb-ehci-prevent-missed-ehci-interrupts-with-edge-triggered-msi.patch

diff --git a/queue-5.10/usb-ehci-prevent-missed-ehci-interrupts-with-edge-triggered-msi.patch b/queue-5.10/usb-ehci-prevent-missed-ehci-interrupts-with-edge-triggered-msi.patch
new file mode 100644 (file)
index 0000000..b57a907
--- /dev/null
+++ b/queue-5.10/usb-ehci-prevent-missed-ehci-interrupts-with-edge-triggered-msi.patch
@@ -0,0 +1,85 @@
+From 0b60557230adfdeb8164e0b342ac9cd469a75759 Mon Sep 17 00:00:00 2001
+From: David Jeffery <djeffery@redhat.com>
+Date: Thu, 15 Jul 2021 17:37:44 -0400
+Subject: usb: ehci: Prevent missed ehci interrupts with edge-triggered MSI
+
+From: David Jeffery <djeffery@redhat.com>
+
+commit 0b60557230adfdeb8164e0b342ac9cd469a75759 upstream.
+
+When MSI is used by the ehci-hcd driver, it can cause lost interrupts which
+results in EHCI only continuing to work due to a polling fallback. But the
+reliance of polling drastically reduces performance of any I/O through EHCI.
+
+Interrupts are lost as the EHCI interrupt handler does not safely handle
+edge-triggered interrupts. It fails to ensure all interrupt status bits are
+cleared, which works with level-triggered interrupts but not the
+edge-triggered interrupts typical from using MSI.
+
+To fix this problem, check if the driver may have raced with the hardware
+setting additional interrupt status bits and clear status until it is in a
+stable state.
+
+Fixes: 306c54d0edb6 ("usb: hcd: Try MSI interrupts on PCI devices")
+Tested-by: Laurence Oberman <loberman@redhat.com>
+Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
+Acked-by: Alan Stern <stern@rowland.harvard.edu>
+Signed-off-by: David Jeffery <djeffery@redhat.com>
+Link: https://lore.kernel.org/r/20210715213744.GA44506@redhat
+Cc: stable <stable@vger.kernel.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ drivers/usb/host/ehci-hcd.c |   18 ++++++++++++++----
+ 1 file changed, 14 insertions(+), 4 deletions(-)
+
+--- a/drivers/usb/host/ehci-hcd.c
++++ b/drivers/usb/host/ehci-hcd.c
+@@ -703,7 +703,8 @@ EXPORT_SYMBOL_GPL(ehci_setup);
+ static irqreturn_t ehci_irq (struct usb_hcd *hcd)
+ {
+       struct ehci_hcd         *ehci = hcd_to_ehci (hcd);
+-      u32                     status, masked_status, pcd_status = 0, cmd;
++      u32                     status, current_status, masked_status, pcd_status = 0;
++      u32                     cmd;
+       int                     bh;
+       unsigned long           flags;
+ 
+@@ -715,19 +716,22 @@ static irqreturn_t ehci_irq (struct usb_
+        */
+       spin_lock_irqsave(&ehci->lock, flags);
+ 
+-      status = ehci_readl(ehci, &ehci->regs->status);
++      status = 0;
++      current_status = ehci_readl(ehci, &ehci->regs->status);
++restart:
+ 
+       /* e.g. cardbus physical eject */
+-      if (status == ~(u32) 0) {
++      if (current_status == ~(u32) 0) {
+               ehci_dbg (ehci, "device removed\n");
+               goto dead;
+       }
++      status |= current_status;
+ 
+       /*
+        * We don't use STS_FLR, but some controllers don't like it to
+        * remain on, so mask it out along with the other status bits.
+        */
+-      masked_status = status & (INTR_MASK | STS_FLR);
++      masked_status = current_status & (INTR_MASK | STS_FLR);
+ 
+       /* Shared IRQ? */
+       if (!masked_status || unlikely(ehci->rh_state == EHCI_RH_HALTED)) {
+@@ -737,6 +741,12 @@ static irqreturn_t ehci_irq (struct usb_
+ 
+       /* clear (just) interrupts */
+       ehci_writel(ehci, masked_status, &ehci->regs->status);
++
++      /* For edge interrupts, don't race with an interrupt bit being raised */
++      current_status = ehci_readl(ehci, &ehci->regs->status);
++      if (current_status & INTR_MASK)
++              goto restart;
++
+       cmd = ehci_readl(ehci, &ehci->regs->command);
+       bh = 0;
+