On Fri, Jul 16, 2021 at 04:36:18PM +0300, Andy Shevchenko wrote: > On Thu, Jul 15, 2021 at 05:37:44PM -0400, David Jeffery wrote: > > 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. > > > > Signed-off-by: David Jeffery <djeffery@xxxxxxxxxx> > > Tested-by: Laurence Oberman <loberman@xxxxxxxxxx> > > Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> > > Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> > > > Fixes: 306c54d0edb6 usb: hcd: Try MSI interrupts on PCI devices > > Improper format. > > Add to your .gitconfig the following: > > [alias] > one = show -s --pretty='format:%h (\"%s\")' > c = show -s --pretty='format:https://git.kernel.org/torvalds/c/%h' And this [core] abbrev = 12 `git one $COMMIT` will give you a nice representation. -- With Best Regards, Andy Shevchenko
