[v2,20/22] watchdog: ziirave_wdt: Fix DOWNLOAD_START payload
diff mbox series

Message ID 20190812200906.31344-21-andrew.smirnov@gmail.com
State Accepted
Headers show
Series
  • Ziirave_wdt driver fixes
Related show

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] 0x10 [A] P

using ziirave_firm_write_byte() will result in

S Addr Wr [A] 0x10 [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 | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

Comments

Guenter Roeck Aug. 15, 2019, 6:24 p.m. UTC | #1
On Mon, Aug 12, 2019 at 01:09:04PM -0700, Andrey Smirnov wrote:
> Bootloader firmware expects the following traffic for DOWNLOAD_END:
> 
> S Addr Wr [A] 0x10 [A] P
> 
> using ziirave_firm_write_byte() will result in
> 
> S Addr Wr [A] 0x10 [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>

Patch
diff mbox series

diff --git a/drivers/watchdog/ziirave_wdt.c b/drivers/watchdog/ziirave_wdt.c
index 681f65349779..ed69fa82e09c 100644
--- a/drivers/watchdog/ziirave_wdt.c
+++ b/drivers/watchdog/ziirave_wdt.c
@@ -217,13 +217,6 @@  static int ziirave_firm_write_block_data(struct watchdog_device *wdd,
 	return ret;
 }
 
-static int ziirave_firm_write_byte(struct watchdog_device *wdd, u8 command,
-				   u8 byte, bool wait_for_ack)
-{
-	return ziirave_firm_write_block_data(wdd, command, 1, &byte,
-					     wait_for_ack);
-}
-
 static bool ziirave_firm_addr_readonly(u32 addr)
 {
 	return addr < ZIIRAVE_FIRM_FLASH_MEMORY_START ||
@@ -375,12 +368,18 @@  static int ziirave_firm_upload(struct watchdog_device *wdd,
 
 	msleep(500);
 
-	ret = ziirave_firm_write_byte(wdd, ZIIRAVE_CMD_DOWNLOAD_START, 1, true);
+	ret = i2c_smbus_write_byte(client, ZIIRAVE_CMD_DOWNLOAD_START);
 	if (ret) {
 		dev_err(&client->dev, "Failed to start download\n");
 		return ret;
 	}
 
+	ret = ziirave_firm_read_ack(wdd);
+	if (ret) {
+		dev_err(&client->dev, "No ACK for start download\n");
+		return ret;
+	}
+
 	msleep(500);
 
 	for (rec = (void *)fw->data; rec; rec = ihex_next_binrec(rec)) {