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From:   Yann Gautier <yann.gautier@foss.st.com>
To:     Ulf Hansson <ulf.hansson@linaro.org>, <linux-mmc@vger.kernel.org>
CC:     Russell King <linux@armlinux.org.uk>,
        Philipp Zabel <p.zabel@pengutronix.de>,
        Christophe Kerello <christophe.kerello@foss.st.com>,
        Rob Herring <robh@kernel.org>,
        Xiang wangx <wangxiang@cdjrlc.com>,
        Yang Yingliang <yangyingliang@huawei.com>,
        <linux-kernel@vger.kernel.org>, Marek Vasut <marex@denx.de>,
        Linus Walleij <linus.walleij@linaro.org>,
        Dennis Zhou <dennis@kernel.org>,
        Yann Gautier <yann.gautier@foss.st.com>
Subject: [PATCH] mmc: mmci: stm32: fix max busy timeout calculation
Date:   Tue, 13 Jun 2023 15:41:46 +0200
Message-ID: <20230613134146.418016-1-yann.gautier@foss.st.com>
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From: Christophe Kerello <christophe.kerello@foss.st.com>

The way that the timeout is currently calculated could lead to a u64
timeout value in mmci_start_command(). This value is then cast in a u32
register that leads to mmc erase failed issue with some SD cards.

Fixes: 8266c585f489 ("mmc: mmci: add hardware busy timeout feature")
Signed-off-by: Yann Gautier <yann.gautier@foss.st.com>
Signed-off-by: Christophe Kerello <christophe.kerello@foss.st.com>
---
 drivers/mmc/host/mmci.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index f2b2e8b0574e8..696cbef3ff7de 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -1735,7 +1735,8 @@ static void mmci_set_max_busy_timeout(struct mmc_host *mmc)
 		return;
 
 	if (host->variant->busy_timeout && mmc->actual_clock)
-		max_busy_timeout = ~0UL / (mmc->actual_clock / MSEC_PER_SEC);
+		max_busy_timeout = U32_MAX / DIV_ROUND_UP(mmc->actual_clock,
+							  MSEC_PER_SEC);
 
 	mmc->max_busy_timeout = max_busy_timeout;
 }
-- 
2.25.1