From: Ed Spiridonov <edo.rus@gmail.com>
Date: Fri, 4 Mar 2016 06:07:27 +0000 (+0300)
Subject: can: mcp251x: avoid write to error flag register if it's unnecessary
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=d694b06c42a56c9610861ee0474b4d441af8ada6;p=linux-beck.git

can: mcp251x: avoid write to error flag register if it's unnecessary

Only two bits (RX0OVR and RX1OVR) are writable in EFLG, write is useless
if these bits aren't set.

Signed-off-by: Ed Spiridonov <edo.rus@gmail.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---

diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index 575790e8a75a..74a7dfecee27 100644
--- a/drivers/net/can/spi/mcp251x.c
+++ b/drivers/net/can/spi/mcp251x.c
@@ -843,7 +843,7 @@ static irqreturn_t mcp251x_can_ist(int irq, void *dev_id)
 		if (clear_intf)
 			mcp251x_write_bits(spi, CANINTF, clear_intf, 0x00);
 
-		if (eflag)
+		if (eflag & (EFLG_RX0OVR | EFLG_RX1OVR))
 			mcp251x_write_bits(spi, EFLG, eflag, 0x00);
 
 		/* Update can state */