2023-06-13 13:51:27

by Yann Gautier

Subject: [PATCH] mmc: mmci: stm32: fix max busy timeout calculation

From: Christophe Kerello <[email protected]>

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 <[email protected]>
Signed-off-by: Christophe Kerello <[email protected]>
---
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

2023-06-13 14:40:22

by Ulf Hansson

Subject: Re: [PATCH] mmc: mmci: stm32: fix max busy timeout calculation

On Tue, 13 Jun 2023 at 15:42, Yann Gautier <[email protected]> wrote:
>
> From: Christophe Kerello <[email protected]>
>
> 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 <[email protected]>
> Signed-off-by: Christophe Kerello <[email protected]>

Applied for fixes and by adding a stable tag, thanks!

Kind regards
Uffe

> ---
> 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
>