mmc:sdhci: restore the enabled dma when do reset all

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(-)

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);

>-----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 = 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, 
Shaohui Xie