[PATCH 5.18 047/339] watchdog: rzg2l_wdt: Fix 32bit overflow issue

From: Greg Kroah-Hartman
Date: Mon Jun 13 2022 - 09:35:41 EST


From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>

[ Upstream commit ea2949df22a533cdf75e4583c00b1ce94cd5a83b ]

The value of timer_cycle_us can be 0 due to 32bit overflow.
For eg:- If we assign the counter value "0xfff" for computing
maxval.

This patch fixes this issue by appending ULL to 1024, so that
it is promoted to 64bit.

This patch also fixes the warning message, 'watchdog: Invalid min and
max timeout values, resetting to 0!'.

Fixes: 2cbc5cd0b55fa2 ("watchdog: Add Watchdog Timer driver for RZ/G2L")
Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
Reviewed-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Link: https://lore.kernel.org/r/20220225175320.11041-2-biju.das.jz@xxxxxxxxxxxxxx
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Wim Van Sebroeck <wim@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/watchdog/rzg2l_wdt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/watchdog/rzg2l_wdt.c b/drivers/watchdog/rzg2l_wdt.c
index 6b426df34fd6..96f2a018ab62 100644
--- a/drivers/watchdog/rzg2l_wdt.c
+++ b/drivers/watchdog/rzg2l_wdt.c
@@ -53,7 +53,7 @@ static void rzg2l_wdt_wait_delay(struct rzg2l_wdt_priv *priv)

static u32 rzg2l_wdt_get_cycle_usec(unsigned long cycle, u32 wdttime)
{
- u64 timer_cycle_us = 1024 * 1024 * (wdttime + 1) * MICRO;
+ u64 timer_cycle_us = 1024 * 1024ULL * (wdttime + 1) * MICRO;

return div64_ul(timer_cycle_us, cycle);
}
--
2.35.1