aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorJacky Bai <[email protected]>2022-08-25 16:32:51 +0800
committerWim Van Sebroeck <[email protected]>2022-10-02 12:55:44 +0200
commit6371593fbad75cfb9ee14e8b462a5ebb1aa38c02 (patch)
tree2567f47141eaf5e5925bac663127cca15cd43172
parentf182683333b5d8ac4af64517b6e3c444c4579e6e (diff)
watchdog: imx7ulp: Add explict memory barrier for unlock sequence
When reconfiguring the WDOG Timer of i.MX7ULP, there is a certain probability causes it to reset. The reason is that the CMD32EN of the WDOG Timer of i.MX7ULP is disabled in bootloader. The unlock sequence are two 16-bit writes to the CNT register within 16 bus clocks. Adding mb() is to guarantee that two 16-bit writes are finished within 16 bus clocks. Memory barriers cannot be added between these two 16-bit writes so that writel_relaxed is used. Suggested-by: Ye Li <[email protected]> Signed-off-by: Jacky Bai <[email protected]> Signed-off-by: Alice Guo <[email protected]> Reviewed-by: Ye Li <[email protected]> Reviewed-by: Guenter Roeck <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Guenter Roeck <[email protected]> Signed-off-by: Wim Van Sebroeck <[email protected]>
-rw-r--r--drivers/watchdog/imx7ulp_wdt.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/watchdog/imx7ulp_wdt.c b/drivers/watchdog/imx7ulp_wdt.c
index 014f497ea0dc..b8ac0cb04d2f 100644
--- a/drivers/watchdog/imx7ulp_wdt.c
+++ b/drivers/watchdog/imx7ulp_wdt.c
@@ -179,9 +179,13 @@ static int imx7ulp_wdt_init(void __iomem *base, unsigned int timeout)
int ret;
local_irq_disable();
+
+ mb();
/* unlock the wdog for reconfiguration */
writel_relaxed(UNLOCK_SEQ0, base + WDOG_CNT);
writel_relaxed(UNLOCK_SEQ1, base + WDOG_CNT);
+ mb();
+
ret = imx7ulp_wdt_wait(base, WDOG_CS_ULK);
if (ret)
goto init_out;