[PATCH 3/4] mmc: mmci: stm32: clear DLYB_CR after sending tuning command

[Marek Vasut]

On 12/15/21 15:17, Yann Gautier wrote:
> During test campaign, and especially after several unbind/bind sequences,
> it has been seen that the SD-card on SDMMC1 thread could freeze.
> The freeze always appear on a CMD23 following a CMD19.
> Checking SDMMC internal registers shows that the tuning command (CMD19)
> has failed.
> The freeze is then due to the delay block involved in the tuning sequence.
> To correct this, clear the delay block register DLYB_CR register after
> the tuning commands.
> 
> Signed-off-by: Christophe Kerello <christophe.kerello at foss.st.com>
> Signed-off-by: Yann Gautier <yann.gautier at foss.st.com>
> ---
>   drivers/mmc/host/mmci_stm32_sdmmc.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/mmc/host/mmci_stm32_sdmmc.c b/drivers/mmc/host/mmci_stm32_sdmmc.c
> index fdaa11f92fe6..a75d3dd34d18 100644
> --- a/drivers/mmc/host/mmci_stm32_sdmmc.c
> +++ b/drivers/mmc/host/mmci_stm32_sdmmc.c
> @@ -441,6 +441,8 @@ static int sdmmc_dlyb_phase_tuning(struct mmci_host *host, u32 opcode)
>   		return -EINVAL;
>   	}
>   
> +	writel_relaxed(0, dlyb->base + DLYB_CR);
> +
>   	phase = end_of_len - max_len / 2;
>   	sdmmc_dlyb_set_cfgr(dlyb, dlyb->unit, phase, false);

Shouldn't this have a Fixes: tag and be CC stable ?
This seems like a bugfix, no ?