Commit 667f3d1a authored by Guenter Roeck's avatar Guenter Roeck Committed by sanglipeng1
Browse files

usb: ohci: Prevent missed ohci interrupts 

stable inclusion
from stable-v5.10.217
commit 3afc842e66826ded440da63cd617514507f922fe
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IAWLXC

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=3afc842e66826ded440da63cd617514507f922fe



--------------------------------

commit fe81f354841641c7f71163b84912b25c169ed8ec upstream.

Testing ohci functionality with qemu's pci-ohci emulation often results
in ohci interface stalls, resulting in hung task timeouts.

The problem is caused by lost interrupts between the emulation and the
Linux kernel code. Additional interrupts raised while the ohci interrupt
handler in Linux is running and before the handler clears the interrupt
status are not handled. The fix for a similar problem in ehci suggests
that the problem is likely caused by edge-triggered MSI interrupts. See
commit 0b605572 ("usb: ehci: Prevent missed ehci interrupts with
edge-triggered MSI") for details.

Ensure that the ohci interrupt code handles all pending interrupts before
returning to solve the problem.

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: David Laight <David.Laight@aculab.com>
Cc: stable@vger.kernel.org
Fixes: 306c54d0 ("usb: hcd: Try MSI interrupts on PCI devices")
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Reviewed-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Reviewed-by: default avatarGerd Hoffmann <kraxel@redhat.com>
Link: https://lore.kernel.org/r/20240429154010.1507366-1-linux@roeck-us.net


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarsanglipeng1 <sanglipeng1@jd.com>
parent 1572667d

drivers/usb/host/ohci-hcd.c

+8 −0
Original line number Diff line number Diff line
@@ -890,6 +890,7 @@ static irqreturn_t ohci_irq (struct usb_hcd *hcd) 
	/* Check for an all 1's result which is a typical consequence

	 * of dead, unclocked, or unplugged (CardBus...) devices

	 */

again:

	if (ints == ~(u32)0) {

		ohci->rh_state = OHCI_RH_HALTED;

		ohci_dbg (ohci, "device removed!\n");
@@ -984,6 +985,13 @@ static irqreturn_t ohci_irq (struct usb_hcd *hcd) 
	}

	spin_unlock(&ohci->lock);



	/* repeat until all enabled interrupts are handled */

	if (ohci->rh_state != OHCI_RH_HALTED) {

		ints = ohci_readl(ohci, &regs->intrstatus);

		if (ints && (ints & ohci_readl(ohci, &regs->intrenable)))

			goto again;

	}



	return IRQ_HANDLED;

}