From: Grazvydas Ignotas <notasas@gmail.com>
Date: Sat, 4 Jul 2015 20:51:00 +0000 (+0300)
Subject: usb: musb: clear MUSB_INTR_SOF
X-Git-Tag: sz_173~11
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=621367ef474da0e2ec390abbb2251ba192e2312c

usb: musb: clear MUSB_INTR_SOF

MUSB_INTR_SOF is always masked, but still shows up in status register
and causes musb_stage0_irq() to be called needlessly, then work to be
scheduled at the end of musb_stage0_irq(), and that doubles context
switch count.
---

diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 7245b89b020a..650a18bc2650 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -1522,6 +1522,8 @@ static irqreturn_t generic_interrupt(int irq, void *__hci)
 	spin_lock_irqsave(&musb->lock, flags);
 
 	musb->int_usb = musb_readb(musb->mregs, MUSB_INTRUSB);
+	/* SOF is not enabled, but status is still often set */
+	musb->int_usb &= ~MUSB_INTR_SOF;
 	musb->int_tx = musb_readw(musb->mregs, MUSB_INTRTX);
 	musb->int_rx = musb_readw(musb->mregs, MUSB_INTRRX);