[PATCH] mmc:sdhci: restore the enabled dma when do reset all

[PATCH] mmc:sdhci: restore the enabled dma when do reset all

[Shaohui Xie]

If dma is enabled, it'll be cleared when reset all is performed, this can
be observed on some platforms, such as P2041 which has a version 2.3
controller, but platform like P4080 which has a version 2.2 controller,
does not suffer this, so we will check if the dma is enabled, we should
restore it after reset all.

Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
---
based on http://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc.git,
branch 'for-linus'.

 drivers/mmc/host/sdhci.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 19ed580..22033c3 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -29,6 +29,7 @@
 #include <linux/mmc/host.h>
 
 #include "sdhci.h"
+#include "sdhci-esdhc.h"
 
 #define DRIVER_NAME "sdhci"
 
@@ -176,6 +177,7 @@ static void sdhci_reset(struct sdhci_host *host, u8 mask)
 {
 	unsigned long timeout;
 	u32 uninitialized_var(ier);
+	u32 uninitialized_var(dma);
 
 	if (host->quirks & SDHCI_QUIRK_NO_CARD_NO_RESET) {
 		if (!(sdhci_readl(host, SDHCI_PRESENT_STATE) &
@@ -189,6 +191,8 @@ static void sdhci_reset(struct sdhci_host *host, u8 mask)
 	if (host->ops->platform_reset_enter)
 		host->ops->platform_reset_enter(host, mask);
 
+	dma = sdhci_readl(host, ESDHC_DMA_SYSCTL);
+
 	sdhci_writeb(host, mask, SDHCI_SOFTWARE_RESET);
 
 	if (mask & SDHCI_RESET_ALL)
@@ -214,6 +218,9 @@ static void sdhci_reset(struct sdhci_host *host, u8 mask)
 
 	if (host->quirks & SDHCI_QUIRK_RESTORE_IRQS_AFTER_RESET)
 		sdhci_clear_set_irqs(host, SDHCI_INT_ALL_MASK, ier);
+
+	if ((dma & ESDHC_DMA_SNOOP) && (mask & SDHCI_RESET_ALL))
+		sdhci_writel(host, dma, ESDHC_DMA_SYSCTL);
 }
 
 static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios);
-- 
1.6.4

Re: [PATCH] mmc:sdhci: restore the enabled dma when do reset all

[Adrian Hunter]

On 28/12/11 11:41, Shaohui Xie wrote:
> If dma is enabled, it'll be cleared when reset all is performed, this can
> be observed on some platforms, such as P2041 which has a version 2.3
> controller, but platform like P4080 which has a version 2.2 controller,
> does not suffer this, so we will check if the dma is enabled, we should
> restore it after reset all.
> 
> Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
> ---
> based on http://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc.git,
> branch 'for-linus'.
> 
>  drivers/mmc/host/sdhci.c |    7 +++++++
>  1 files changed, 7 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 19ed580..22033c3 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -29,6 +29,7 @@
>  #include <linux/mmc/host.h>
>  
>  #include "sdhci.h"
> +#include "sdhci-esdhc.h"
>  
>  #define DRIVER_NAME "sdhci"
>  
> @@ -176,6 +177,7 @@ static void sdhci_reset(struct sdhci_host *host, u8 mask)
>  {
>  	unsigned long timeout;
>  	u32 uninitialized_var(ier);
> +	u32 uninitialized_var(dma);
>  
>  	if (host->quirks & SDHCI_QUIRK_NO_CARD_NO_RESET) {
>  		if (!(sdhci_readl(host, SDHCI_PRESENT_STATE) &
> @@ -189,6 +191,8 @@ static void sdhci_reset(struct sdhci_host *host, u8 mask)
>  	if (host->ops->platform_reset_enter)
>  		host->ops->platform_reset_enter(host, mask);
>  
> +	dma = sdhci_readl(host, ESDHC_DMA_SYSCTL);


You must not access eSDHC-specific registers in generic SDHCI code


> +
>  	sdhci_writeb(host, mask, SDHCI_SOFTWARE_RESET);
>  
>  	if (mask & SDHCI_RESET_ALL)
> @@ -214,6 +218,9 @@ static void sdhci_reset(struct sdhci_host *host, u8 mask)
>  
>  	if (host->quirks & SDHCI_QUIRK_RESTORE_IRQS_AFTER_RESET)
>  		sdhci_clear_set_irqs(host, SDHCI_INT_ALL_MASK, ier);
> +
> +	if ((dma & ESDHC_DMA_SNOOP) && (mask & SDHCI_RESET_ALL))
> +		sdhci_writel(host, dma, ESDHC_DMA_SYSCTL);
>  }
>  
>  static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios);

RE: [PATCH] mmc:sdhci: restore the enabled dma when do reset all

[Xie Shaohui-B21989]

>-----Original Message-----
>From: Adrian Hunter [mailto:adrian.hunter@intel.com]
>Sent: Wednesday, December 28, 2011 7:43 PM
>To: Xie Shaohui-B21989
>Cc: linux-mmc@vger.kernel.org; linuxppc-dev@lists.ozlabs.org
>Subject: Re: [PATCH] mmc:sdhci: restore the enabled dma when do reset all
>
>On 28/12/11 11:41, Shaohui Xie wrote:
>> If dma is enabled, it'll be cleared when reset all is performed, this
>> can be observed on some platforms, such as P2041 which has a version
>> 2.3 controller, but platform like P4080 which has a version 2.2
>> controller, does not suffer this, so we will check if the dma is
>> enabled, we should restore it after reset all.
>>
>> Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
>> ---
>> based on http://git.kernel.org/pub/scm/linux/kernel/git/cjb/mmc.git,
>> branch 'for-linus'.
>>
>>  drivers/mmc/host/sdhci.c |    7 +++++++
>>  1 files changed, 7 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index
>> 19ed580..22033c3 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -29,6 +29,7 @@
>>  #include <linux/mmc/host.h>
>>
>>  #include "sdhci.h"
>> +#include "sdhci-esdhc.h"
>>
>>  #define DRIVER_NAME "sdhci"
>>
>> @@ -176,6 +177,7 @@ static void sdhci_reset(struct sdhci_host *host,
>> u8 mask)  {
>>  	unsigned long timeout;
>>  	u32 uninitialized_var(ier);
>> +	u32 uninitialized_var(dma);
>>
>>  	if (host->quirks & SDHCI_QUIRK_NO_CARD_NO_RESET) {
>>  		if (!(sdhci_readl(host, SDHCI_PRESENT_STATE) & @@ -189,6
>+191,8 @@
>> static void sdhci_reset(struct sdhci_host *host, u8 mask)
>>  	if (host->ops->platform_reset_enter)
>>  		host->ops->platform_reset_enter(host, mask);
>>
>> +	dma =3D sdhci_readl(host, ESDHC_DMA_SYSCTL);
>
>
>You must not access eSDHC-specific registers in generic SDHCI code
[Xie Shaohui] OK. Thank you, I'll call the wrapper API here.


Best Regards,=20
Shaohui Xie