[PATCH 5.10 431/717] watchdog: sprd: check busy bit before new loading rather than after that

Greg Kroah-Hartman
2020-12-28T14:20:00Z

From: Lingling Xu <ling_ling.xu@unisoc.com>

[ Upstream commit 3e07d240939803bed9feb2a353d94686a411a7ca ]

As the specification described, users must check busy bit before start
a new loading operation to make sure that the previous loading is done
and the device is ready to accept a new one.

[ chunyan: Massaged changelog ]

Fixes: 477603467009 ("watchdog: Add Spreadtrum watchdog driver")
Signed-off-by: Lingling Xu <ling_ling.xu@unisoc.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20201029023933.24548-3-zhang.lyra@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/watchdog/sprd_wdt.c | 25 +++++++++++++------------
1 file changed, 13 insertions(+), 12 deletions(-)

diff --git a/drivers/watchdog/sprd_wdt.c b/drivers/watchdog/sprd_wdt.c
index f3c90b4afead1..b9b1daa9e2a4c 100644
--- a/drivers/watchdog/sprd_wdt.c
+++ b/drivers/watchdog/sprd_wdt.c
@@ -108,18 +108,6 @@ static int sprd_wdt_load_value(struct sprd_wdt *wdt, u32 timeout,
u32 tmr_step = timeout * SPRD_WDT_CNT_STEP;
u32 prtmr_step = pretimeout * SPRD_WDT_CNT_STEP;

- sprd_wdt_unlock(wdt->base);
- writel_relaxed((tmr_step >> SPRD_WDT_CNT_HIGH_SHIFT) &
- SPRD_WDT_LOW_VALUE_MASK, wdt->base + SPRD_WDT_LOAD_HIGH);
- writel_relaxed((tmr_step & SPRD_WDT_LOW_VALUE_MASK),
- wdt->base + SPRD_WDT_LOAD_LOW);
- writel_relaxed((prtmr_step >> SPRD_WDT_CNT_HIGH_SHIFT) &
- SPRD_WDT_LOW_VALUE_MASK,
- wdt->base + SPRD_WDT_IRQ_LOAD_HIGH);
- writel_relaxed(prtmr_step & SPRD_WDT_LOW_VALUE_MASK,
- wdt->base + SPRD_WDT_IRQ_LOAD_LOW);
- sprd_wdt_lock(wdt->base);
-
/*
* Waiting the load value operation done,
* it needs two or three RTC clock cycles.
@@ -134,6 +122,19 @@ static int sprd_wdt_load_value(struct sprd_wdt *wdt, u32 timeout,

if (delay_cnt >= SPRD_WDT_LOAD_TIMEOUT)
return -EBUSY;
+
+ sprd_wdt_unlock(wdt->base);
+ writel_relaxed((tmr_step >> SPRD_WDT_CNT_HIGH_SHIFT) &
+ SPRD_WDT_LOW_VALUE_MASK, wdt->base + SPRD_WDT_LOAD_HIGH);
+ writel_relaxed((tmr_step & SPRD_WDT_LOW_VALUE_MASK),
+ wdt->base + SPRD_WDT_LOAD_LOW);
+ writel_relaxed((prtmr_step >> SPRD_WDT_CNT_HIGH_SHIFT) &
+ SPRD_WDT_LOW_VALUE_MASK,
+ wdt->base + SPRD_WDT_IRQ_LOAD_HIGH);
+ writel_relaxed(prtmr_step & SPRD_WDT_LOW_VALUE_MASK,
+ wdt->base + SPRD_WDT_IRQ_LOAD_LOW);
+ sprd_wdt_lock(wdt->base);
+
return 0;
}

--
2.27.0