On 08/14/2017 07:45 PM, Huibin Hong wrote:
If top is 15, (1 << (16 + top)) may be negative.
Signed-off-by: Huibin Hong <huibin.hong@xxxxxxxxxxxxxx>
---
Changes in v2:
- Rebase mainline Linux 4.13-rc5
drivers/watchdog/dw_wdt.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c
index 36be987..59ed958 100644
--- a/drivers/watchdog/dw_wdt.c
+++ b/drivers/watchdog/dw_wdt.c
@@ -72,7 +72,9 @@ static inline int dw_wdt_top_in_seconds(struct dw_wdt *dw_wdt, unsigned top)
* There are 16 possible timeout values in 0..15 where the number of
* cycles is 2 ^ (16 + i) and the watchdog counts down.
*/
- return (1U << (16 + top)) / dw_wdt->rate;
+ unsigned int cycles = 1 << (16 + top);
+
+ return (cycles / clk_get_rate(dw_wdt.clk));
Sorry I didn't catch this earlier. Why not use dw_wdt->rate ?
It has been checked against 0, and presumably the rate does not change
on its own. If it can change, you'll have to submit a separate patch
dropping the use of dw_wdt->rate entirely and explaining the reason.
You'll also have to make sure that the driver somehow catches the
rate change and adjusts its settings automatically; otherwise, timeouts
will be off target, and the system can reset unexpectedly.
Thanks,
Guenter
}
static int dw_wdt_get_top(struct dw_wdt *dw_wdt)
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