usb: ohci: disable start-of-frame interrupt in ohci_rh_suspend
authorYinbo Zhu <zhuyinbo@loongson.cn>
Wed, 13 Oct 2021 03:32:08 +0000 (11:32 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 21 Oct 2021 10:48:18 +0000 (12:48 +0200)
commit20f588ac9841edaf3e03fb24afe43ee530622a3c
tree7dbfc2d934bed3f72bc517b03d8f0fc070f66e47
parent6a47856145346c2dc5f31e1b5f9d986f1e446ce2
usb: ohci: disable start-of-frame interrupt in ohci_rh_suspend

While going into S3 or S4 suspend, an OHCI host controller can
generate interrupt requests if the INTR_SF enable flag is set.  The
interrupt handler routine isn't prepared for this and it doesn't turn
off the flag, causing an interrupt storm.

To fix this problem, make ohci_rh_suspend() always disable INTR_SF
interrupts after processing the done list and the ED unlinks but
before the controller goes into the suspended (non-UsbOperational)
state.  There's no reason to leave the flag enabled, since a
suspended controller doesn't generate Start-of-Frame packets.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Yinbo Zhu <zhuyinbo@loongson.cn>
Link: https://lore.kernel.org/r/1634095928-29639-1-git-send-email-zhuyinbo@loongson.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/host/ohci-hub.c