can: mcp251x: read-modify-write eflag only when needed
Use read-modify-write instead of a simple write to change the register
contents, to close existing the race window between the original manual
read and write.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Wolfgang Grandegger <wg@grandegger.com>
diff --git a/drivers/net/can/mcp251x.c b/drivers/net/can/mcp251x.c
index 9b3466a..7e2f951 100644
--- a/drivers/net/can/mcp251x.c
+++ b/drivers/net/can/mcp251x.c
@@ -785,7 +785,8 @@
mcp251x_write_bits(spi, CANINTF, intf, 0x00);
- mcp251x_write_reg(spi, EFLG, 0x00);
+ if (eflag)
+ mcp251x_write_bits(spi, EFLG, eflag, 0x00);
/* Update can state */
if (eflag & EFLG_TXBO) {