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From: Biju Das <biju.das.jz@bp.renesas.com>
To: Wim Van Sebroeck <wim@linux-watchdog.org>,
	Guenter Roeck <linux@roeck-us.net>
Cc: Biju Das <biju.das.jz@bp.renesas.com>,
	linux-watchdog@vger.kernel.org,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Chris Paterson <Chris.Paterson2@renesas.com>,
	Biju Das <biju.das@bp.renesas.com>,
	Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	linux-renesas-soc@vger.kernel.org
Subject: [PATCH v3 1/4] watchdog: rzg2l_wdt: Fix 32bit overflow issue
Date: Tue,  4 Jan 2022 18:12:45 +0000	[thread overview]
Message-ID: <20220104181249.3174-1-biju.das.jz@bp.renesas.com> (raw)

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.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
v2->v3:
 * No change
V1->V2:
 * Added Rb tag from Guenter and Geert.
---
 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);
 }
-- 
2.17.1


             reply	other threads:[~2022-01-04 18:12 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-04 18:12 Biju Das [this message]
2022-01-04 18:12 ` [PATCH v3 2/4] watchdog: rzg2l_wdt: Use force reset for WDT reset Biju Das
2022-01-10  9:51   ` Geert Uytterhoeven
2022-01-10 10:50     ` Biju Das
2022-01-10 10:57       ` Geert Uytterhoeven
2022-01-10 11:19         ` Biju Das
2022-01-04 18:12 ` [PATCH v3 3/4] watchdog: rzg2l_wdt: Add error check for reset_control_deassert Biju Das
2022-01-04 18:12 ` [PATCH v3 4/4] watchdog: rzg2l_wdt: Add set_timeout callback Biju Das

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