From 20f588ac9841edaf3e03fb24afe43ee530622a3c Mon Sep 17 00:00:00 2001
From: Yinbo Zhu <zhuyinbo@loongson.cn>
Date: Wed, 13 Oct 2021 11:32:08 +0800
Subject: [PATCH] usb: ohci: disable start-of-frame interrupt in
 ohci_rh_suspend
Git-commit: 20f588ac9841edaf3e03fb24afe43ee530622a3c
References: git-fixes
Patch-mainline: v5.16-rc1

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>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
 drivers/usb/host/ohci-hub.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/host/ohci-hub.c b/drivers/usb/host/ohci-hub.c
index f474f2f9c1e4..90cee192e96d 100644
--- a/drivers/usb/host/ohci-hub.c
+++ b/drivers/usb/host/ohci-hub.c
@@ -91,6 +91,9 @@ __acquires(ohci->lock)
 	update_done_list(ohci);
 	ohci_work(ohci);
 
+	/* All ED unlinks should be finished, no need for SOF interrupts */
+	ohci_writel(ohci, OHCI_INTR_SF, &ohci->regs->intrdisable);
+
 	/*
 	 * Some controllers don't handle "global" suspend properly if
 	 * there are unsuspended ports.  For these controllers, put all
-- 
2.26.2