diff mbox series

[v2,17/22] watchdog: ziirave_wdt: Fix DOWNLOAD_END payload

Message ID 20190812200906.31344-18-andrew.smirnov@gmail.com
State Accepted
Headers show
Series Ziirave_wdt driver fixes | expand

Commit Message

Andrey Smirnov Aug. 12, 2019, 8:09 p.m. UTC
Bootloader firmware expects the following traffic for DOWNLOAD_END:

S Addr Wr [A] 0x11 [A] P

using ziirave_firm_write_byte() will result in

S Addr Wr [A] 0x11 [A] 0x01 [A] 0x01 [A] P

which happens to work because firmware will ignore any extra bytes
sent. Fix this by converting the code to use i2c_smbus_write_byte()
instead.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Cc: Chris Healy <cphealy@gmail.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Rick Ramstetter <rick@anteaterllc.com>
Cc: linux-watchdog@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/watchdog/ziirave_wdt.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Guenter Roeck Aug. 15, 2019, 6:23 p.m. UTC | #1
On Mon, Aug 12, 2019 at 01:09:01PM -0700, Andrey Smirnov wrote:
> Bootloader firmware expects the following traffic for DOWNLOAD_END:
> 
> S Addr Wr [A] 0x11 [A] P
> 
> using ziirave_firm_write_byte() will result in
> 
> S Addr Wr [A] 0x11 [A] 0x01 [A] 0x01 [A] P
> 
> which happens to work because firmware will ignore any extra bytes
> sent. Fix this by converting the code to use i2c_smbus_write_byte()
> instead.
> 
> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
> Cc: Chris Healy <cphealy@gmail.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Rick Ramstetter <rick@anteaterllc.com>
> Cc: linux-watchdog@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
diff mbox series

Patch

diff --git a/drivers/watchdog/ziirave_wdt.c b/drivers/watchdog/ziirave_wdt.c
index 0185b9175cc0..a598780d73d3 100644
--- a/drivers/watchdog/ziirave_wdt.c
+++ b/drivers/watchdog/ziirave_wdt.c
@@ -425,7 +425,7 @@  static int ziirave_firm_upload(struct watchdog_device *wdd,
 	}
 
 	/* End download operation */
-	ret = ziirave_firm_write_byte(wdd, ZIIRAVE_CMD_DOWNLOAD_END, 1, false);
+	ret = i2c_smbus_write_byte(client, ZIIRAVE_CMD_DOWNLOAD_END);
 	if (ret) {
 		dev_err(&client->dev,
 			"Failed to end firmware download: %d\n", ret);