2020-05-27 17:06:46

by Eugen Hristev

Subject: [PATCH] mmc: sdhci-of-at91: fix CALCR register being rewritten

When enabling calibration at reset, the CALCR register was completely
rewritten. This may cause certain bits being deleted unintentedly.
Fix by issuing a read-modify-write operation.

Fixes: 727d836a375a ("mmc: sdhci-of-at91: add DT property to enable calibration on full reset")
Signed-off-by: Eugen Hristev <[email protected]>
---
drivers/mmc/host/sdhci-of-at91.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
index 25f4e0f4f53b..1ece2c50042c 100644
--- a/drivers/mmc/host/sdhci-of-at91.c
+++ b/drivers/mmc/host/sdhci-of-at91.c
@@ -121,9 +121,12 @@ static void sdhci_at91_reset(struct sdhci_host *host, u8 mask)
|| mmc_gpio_get_cd(host->mmc) >= 0)
sdhci_at91_set_force_card_detect(host);

- if (priv->cal_always_on && (mask & SDHCI_RESET_ALL))
- sdhci_writel(host, SDMMC_CALCR_ALWYSON | SDMMC_CALCR_EN,
+ if (priv->cal_always_on && (mask & SDHCI_RESET_ALL)) {
+ u32 calcr = sdhci_readl(host, SDMMC_CALCR);
+
+ sdhci_writel(host, calcr | SDMMC_CALCR_ALWYSON | SDMMC_CALCR_EN,
SDMMC_CALCR);
+ }
}

static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
--
2.25.1

2020-05-28 10:20:49

by Ulf Hansson

Subject: Re: [PATCH] mmc: sdhci-of-at91: fix CALCR register being rewritten

On Wed, 27 May 2020 at 12:57, Eugen Hristev <[email protected]> wrote:
>
> When enabling calibration at reset, the CALCR register was completely
> rewritten. This may cause certain bits being deleted unintentedly.
> Fix by issuing a read-modify-write operation.
>
> Fixes: 727d836a375a ("mmc: sdhci-of-at91: add DT property to enable calibration on full reset")
> Signed-off-by: Eugen Hristev <[email protected]>

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

Kind regards
Uffe


> ---
> drivers/mmc/host/sdhci-of-at91.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
> index 25f4e0f4f53b..1ece2c50042c 100644
> --- a/drivers/mmc/host/sdhci-of-at91.c
> +++ b/drivers/mmc/host/sdhci-of-at91.c
> @@ -121,9 +121,12 @@ static void sdhci_at91_reset(struct sdhci_host *host, u8 mask)
> || mmc_gpio_get_cd(host->mmc) >= 0)
> sdhci_at91_set_force_card_detect(host);
>
> - if (priv->cal_always_on && (mask & SDHCI_RESET_ALL))
> - sdhci_writel(host, SDMMC_CALCR_ALWYSON | SDMMC_CALCR_EN,
> + if (priv->cal_always_on && (mask & SDHCI_RESET_ALL)) {
> + u32 calcr = sdhci_readl(host, SDMMC_CALCR);
> +
> + sdhci_writel(host, calcr | SDMMC_CALCR_ALWYSON | SDMMC_CALCR_EN,
> SDMMC_CALCR);
> + }
> }
>
> static const struct sdhci_ops sdhci_at91_sama5d2_ops = {
> --
> 2.25.1
>