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* [PATCH] mmc: sdhci-of-at91: fix set_uhs_signaling rewriting of MC1R
@ 2022-06-30  9:09 ` Eugen Hristev
  0 siblings, 0 replies; 6+ messages in thread
From: Eugen Hristev @ 2022-06-30  9:09 UTC (permalink / raw)
  To: ulf.hansson
  Cc: adrian.hunter, linux-mmc, linux-arm-kernel, linux-kernel,
	Eugen Hristev, Karl Olsen

In set_uhs_signaling, the DDR bit is being set by fully writing the MC1R
register.
This can lead to accidental erase of certain bits in this register.
Avoid this by doing a read-modify-write operation.

Fixes: d0918764c17b ("mmc: sdhci-of-at91: fix MMC_DDR_52 timing selection")
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Tested-by: Karl Olsen <karl@micro-technic.com>
---
 drivers/mmc/host/sdhci-of-at91.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
index 10fb4cb2c731..cd0134580a90 100644
--- a/drivers/mmc/host/sdhci-of-at91.c
+++ b/drivers/mmc/host/sdhci-of-at91.c
@@ -100,8 +100,13 @@ static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock)
 static void sdhci_at91_set_uhs_signaling(struct sdhci_host *host,
 					 unsigned int timing)
 {
-	if (timing == MMC_TIMING_MMC_DDR52)
-		sdhci_writeb(host, SDMMC_MC1R_DDR, SDMMC_MC1R);
+	u8 mc1r;
+
+	if (timing == MMC_TIMING_MMC_DDR52) {
+		mc1r = sdhci_readb(host, SDMMC_MC1R);
+		mc1r |= SDMMC_MC1R_DDR;
+		sdhci_writeb(host, mc1r, SDMMC_MC1R);
+	}
 	sdhci_set_uhs_signaling(host, timing);
 }
 
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH] mmc: sdhci-of-at91: fix set_uhs_signaling rewriting of MC1R
@ 2022-06-30  9:09 ` Eugen Hristev
  0 siblings, 0 replies; 6+ messages in thread
From: Eugen Hristev @ 2022-06-30  9:09 UTC (permalink / raw)
  To: ulf.hansson
  Cc: adrian.hunter, linux-mmc, linux-arm-kernel, linux-kernel,
	Eugen Hristev, Karl Olsen

In set_uhs_signaling, the DDR bit is being set by fully writing the MC1R
register.
This can lead to accidental erase of certain bits in this register.
Avoid this by doing a read-modify-write operation.

Fixes: d0918764c17b ("mmc: sdhci-of-at91: fix MMC_DDR_52 timing selection")
Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
Tested-by: Karl Olsen <karl@micro-technic.com>
---
 drivers/mmc/host/sdhci-of-at91.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
index 10fb4cb2c731..cd0134580a90 100644
--- a/drivers/mmc/host/sdhci-of-at91.c
+++ b/drivers/mmc/host/sdhci-of-at91.c
@@ -100,8 +100,13 @@ static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock)
 static void sdhci_at91_set_uhs_signaling(struct sdhci_host *host,
 					 unsigned int timing)
 {
-	if (timing == MMC_TIMING_MMC_DDR52)
-		sdhci_writeb(host, SDMMC_MC1R_DDR, SDMMC_MC1R);
+	u8 mc1r;
+
+	if (timing == MMC_TIMING_MMC_DDR52) {
+		mc1r = sdhci_readb(host, SDMMC_MC1R);
+		mc1r |= SDMMC_MC1R_DDR;
+		sdhci_writeb(host, mc1r, SDMMC_MC1R);
+	}
 	sdhci_set_uhs_signaling(host, timing);
 }
 
-- 
2.25.1


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH] mmc: sdhci-of-at91: fix set_uhs_signaling rewriting of MC1R
  2022-06-30  9:09 ` Eugen Hristev
@ 2022-07-02 16:51   ` Adrian Hunter
  -1 siblings, 0 replies; 6+ messages in thread
From: Adrian Hunter @ 2022-07-02 16:51 UTC (permalink / raw)
  To: Eugen Hristev, ulf.hansson
  Cc: linux-mmc, linux-arm-kernel, linux-kernel, Karl Olsen

On 30/06/22 12:09, Eugen Hristev wrote:
> In set_uhs_signaling, the DDR bit is being set by fully writing the MC1R
> register.
> This can lead to accidental erase of certain bits in this register.
> Avoid this by doing a read-modify-write operation.
> 
> Fixes: d0918764c17b ("mmc: sdhci-of-at91: fix MMC_DDR_52 timing selection")
> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> Tested-by: Karl Olsen <karl@micro-technic.com>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
>  drivers/mmc/host/sdhci-of-at91.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
> index 10fb4cb2c731..cd0134580a90 100644
> --- a/drivers/mmc/host/sdhci-of-at91.c
> +++ b/drivers/mmc/host/sdhci-of-at91.c
> @@ -100,8 +100,13 @@ static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock)
>  static void sdhci_at91_set_uhs_signaling(struct sdhci_host *host,
>  					 unsigned int timing)
>  {
> -	if (timing == MMC_TIMING_MMC_DDR52)
> -		sdhci_writeb(host, SDMMC_MC1R_DDR, SDMMC_MC1R);
> +	u8 mc1r;
> +
> +	if (timing == MMC_TIMING_MMC_DDR52) {
> +		mc1r = sdhci_readb(host, SDMMC_MC1R);
> +		mc1r |= SDMMC_MC1R_DDR;
> +		sdhci_writeb(host, mc1r, SDMMC_MC1R);
> +	}
>  	sdhci_set_uhs_signaling(host, timing);
>  }
>  


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] mmc: sdhci-of-at91: fix set_uhs_signaling rewriting of MC1R
@ 2022-07-02 16:51   ` Adrian Hunter
  0 siblings, 0 replies; 6+ messages in thread
From: Adrian Hunter @ 2022-07-02 16:51 UTC (permalink / raw)
  To: Eugen Hristev, ulf.hansson
  Cc: linux-mmc, linux-arm-kernel, linux-kernel, Karl Olsen

On 30/06/22 12:09, Eugen Hristev wrote:
> In set_uhs_signaling, the DDR bit is being set by fully writing the MC1R
> register.
> This can lead to accidental erase of certain bits in this register.
> Avoid this by doing a read-modify-write operation.
> 
> Fixes: d0918764c17b ("mmc: sdhci-of-at91: fix MMC_DDR_52 timing selection")
> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> Tested-by: Karl Olsen <karl@micro-technic.com>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
>  drivers/mmc/host/sdhci-of-at91.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
> index 10fb4cb2c731..cd0134580a90 100644
> --- a/drivers/mmc/host/sdhci-of-at91.c
> +++ b/drivers/mmc/host/sdhci-of-at91.c
> @@ -100,8 +100,13 @@ static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock)
>  static void sdhci_at91_set_uhs_signaling(struct sdhci_host *host,
>  					 unsigned int timing)
>  {
> -	if (timing == MMC_TIMING_MMC_DDR52)
> -		sdhci_writeb(host, SDMMC_MC1R_DDR, SDMMC_MC1R);
> +	u8 mc1r;
> +
> +	if (timing == MMC_TIMING_MMC_DDR52) {
> +		mc1r = sdhci_readb(host, SDMMC_MC1R);
> +		mc1r |= SDMMC_MC1R_DDR;
> +		sdhci_writeb(host, mc1r, SDMMC_MC1R);
> +	}
>  	sdhci_set_uhs_signaling(host, timing);
>  }
>  


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] mmc: sdhci-of-at91: fix set_uhs_signaling rewriting of MC1R
  2022-06-30  9:09 ` Eugen Hristev
@ 2022-07-12 11:09   ` Ulf Hansson
  -1 siblings, 0 replies; 6+ messages in thread
From: Ulf Hansson @ 2022-07-12 11:09 UTC (permalink / raw)
  To: Eugen Hristev
  Cc: adrian.hunter, linux-mmc, linux-arm-kernel, linux-kernel, Karl Olsen

On Thu, 30 Jun 2022 at 11:09, Eugen Hristev <eugen.hristev@microchip.com> wrote:
>
> In set_uhs_signaling, the DDR bit is being set by fully writing the MC1R
> register.
> This can lead to accidental erase of certain bits in this register.
> Avoid this by doing a read-modify-write operation.
>
> Fixes: d0918764c17b ("mmc: sdhci-of-at91: fix MMC_DDR_52 timing selection")
> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> Tested-by: Karl Olsen <karl@micro-technic.com>

Applied for next, thanks!

Kind regards
Uffe


> ---
>  drivers/mmc/host/sdhci-of-at91.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
> index 10fb4cb2c731..cd0134580a90 100644
> --- a/drivers/mmc/host/sdhci-of-at91.c
> +++ b/drivers/mmc/host/sdhci-of-at91.c
> @@ -100,8 +100,13 @@ static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock)
>  static void sdhci_at91_set_uhs_signaling(struct sdhci_host *host,
>                                          unsigned int timing)
>  {
> -       if (timing == MMC_TIMING_MMC_DDR52)
> -               sdhci_writeb(host, SDMMC_MC1R_DDR, SDMMC_MC1R);
> +       u8 mc1r;
> +
> +       if (timing == MMC_TIMING_MMC_DDR52) {
> +               mc1r = sdhci_readb(host, SDMMC_MC1R);
> +               mc1r |= SDMMC_MC1R_DDR;
> +               sdhci_writeb(host, mc1r, SDMMC_MC1R);
> +       }
>         sdhci_set_uhs_signaling(host, timing);
>  }
>
> --
> 2.25.1
>

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH] mmc: sdhci-of-at91: fix set_uhs_signaling rewriting of MC1R
@ 2022-07-12 11:09   ` Ulf Hansson
  0 siblings, 0 replies; 6+ messages in thread
From: Ulf Hansson @ 2022-07-12 11:09 UTC (permalink / raw)
  To: Eugen Hristev
  Cc: adrian.hunter, linux-mmc, linux-arm-kernel, linux-kernel, Karl Olsen

On Thu, 30 Jun 2022 at 11:09, Eugen Hristev <eugen.hristev@microchip.com> wrote:
>
> In set_uhs_signaling, the DDR bit is being set by fully writing the MC1R
> register.
> This can lead to accidental erase of certain bits in this register.
> Avoid this by doing a read-modify-write operation.
>
> Fixes: d0918764c17b ("mmc: sdhci-of-at91: fix MMC_DDR_52 timing selection")
> Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>
> Tested-by: Karl Olsen <karl@micro-technic.com>

Applied for next, thanks!

Kind regards
Uffe


> ---
>  drivers/mmc/host/sdhci-of-at91.c | 9 +++++++--
>  1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-at91.c b/drivers/mmc/host/sdhci-of-at91.c
> index 10fb4cb2c731..cd0134580a90 100644
> --- a/drivers/mmc/host/sdhci-of-at91.c
> +++ b/drivers/mmc/host/sdhci-of-at91.c
> @@ -100,8 +100,13 @@ static void sdhci_at91_set_clock(struct sdhci_host *host, unsigned int clock)
>  static void sdhci_at91_set_uhs_signaling(struct sdhci_host *host,
>                                          unsigned int timing)
>  {
> -       if (timing == MMC_TIMING_MMC_DDR52)
> -               sdhci_writeb(host, SDMMC_MC1R_DDR, SDMMC_MC1R);
> +       u8 mc1r;
> +
> +       if (timing == MMC_TIMING_MMC_DDR52) {
> +               mc1r = sdhci_readb(host, SDMMC_MC1R);
> +               mc1r |= SDMMC_MC1R_DDR;
> +               sdhci_writeb(host, mc1r, SDMMC_MC1R);
> +       }
>         sdhci_set_uhs_signaling(host, timing);
>  }
>
> --
> 2.25.1
>

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2022-07-12 11:11 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-06-30  9:09 [PATCH] mmc: sdhci-of-at91: fix set_uhs_signaling rewriting of MC1R Eugen Hristev
2022-06-30  9:09 ` Eugen Hristev
2022-07-02 16:51 ` Adrian Hunter
2022-07-02 16:51   ` Adrian Hunter
2022-07-12 11:09 ` Ulf Hansson
2022-07-12 11:09   ` Ulf Hansson

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