[PATCH v4 0/4]implement eMMC4.4 standard HW reset feature

[PATCH v4 0/4]implement eMMC4.4 standard HW reset feature

[Chuanxiao Dong]

Hi,
	These are the version 4 patches to implement eMMC4.4 HW reset
	feature. Host controller can use this feature by trigger RST_n signal.
	To enable this, byte 162 of EXT_CSD register should be set.
	HW reset is implemented in mmc core layer and sdhci host layer, and it
	will be used after each reading/writing/erasing timeout error occures.

	change-log:
	This version change the way to detect timeout error conditions. Added a
	new routine mmc_handle_timeout_error to do this instead to do this in
	mmc_wait_for_req. Each timeout read/write/erase command can use this
	routine to do HW reset.

	patch1: enable HW reset capability if card support.

	patch2: add two new callback to implement HW reset in mmc core layer. In
	this patch, routine mmc_handle_timeout_error was added.

	patch3: implement hardware_reset callback for sdhci host. A new callback
	reset_emmc was defined which will be each sdhci host controller to
	implement separately.

	patch4: did a HW reset after each read/write/erase command.

Thanks
Chuanxiao

RE: [PATCH v4 0/4]implement eMMC4.4 standard HW reset feature

[Dong, Chuanxiao]

Hello all,
How about these patches? It implemented HW reset feature. When card occurred a timeout error during reading/writing/erasing, these patches will allow driver to reset eMMC card by trigger a HW reset signal.
Does anyone have any comments about the implementation of these patches? Wolfram and Arnd already pointed out the unsuitable patch headers. Thanks! :)


> -----Original Message-----
> From: linux-mmc-owner@vger.kernel.org
> [mailto:linux-mmc-owner@vger.kernel.org] On Behalf Of Chuanxiao Dong
> Sent: Wednesday, December 01, 2010 8:49 PM
> To: linux-mmc@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org; cjb@laptop.org; arjan@linux.intel.com;
> alan@linux.intel.com; akpm@linux-foundation.org
> Subject: [PATCH v4 0/4]implement eMMC4.4 standard HW reset feature
> 
> Hi,
> 	These are the version 4 patches to implement eMMC4.4 HW reset
> 	feature. Host controller can use this feature by trigger RST_n signal.
> 	To enable this, byte 162 of EXT_CSD register should be set.
> 	HW reset is implemented in mmc core layer and sdhci host layer, and it
> 	will be used after each reading/writing/erasing timeout error occures.
> 
> 	change-log:
> 	This version change the way to detect timeout error conditions. Added a
> 	new routine mmc_handle_timeout_error to do this instead to do this in
> 	mmc_wait_for_req. Each timeout read/write/erase command can use this
> 	routine to do HW reset.
> 
> 	patch1: enable HW reset capability if card support.
> 
> 	patch2: add two new callback to implement HW reset in mmc core layer. In
> 	this patch, routine mmc_handle_timeout_error was added.
> 
> 	patch3: implement hardware_reset callback for sdhci host. A new callback
> 	reset_emmc was defined which will be each sdhci host controller to
> 	implement separately.
> 
> 	patch4: did a HW reset after each read/write/erase command.
> 
> Thanks
> Chuanxiao
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH v4 0/4]implement eMMC4.4 standard HW reset feature

[Kyungmin Park]

On Tue, Dec 7, 2010 at 1:03 AM, Dong, Chuanxiao
<chuanxiao.dong@intel.com> wrote:
> Hello all,
> How about these patches? It implemented HW reset feature. When card occurred a timeout error during reading/writing/erasing, these patches will allow driver to reset eMMC card by trigger a HW reset signal.
> Does anyone have any comments about the implementation of these patches? Wolfram and Arnd already pointed out the unsuitable patch headers. Thanks! :)

Hi,
I'm not yet find a reason to use this feature. Now it uses the samsung
and sandisk v4.41 but still no problem.
I wonder what's the purpose and effect if it uses or not?

Thank you,
Kyungmin Park

>
>
>> -----Original Message-----
>> From: linux-mmc-owner@vger.kernel.org
>> [mailto:linux-mmc-owner@vger.kernel.org] On Behalf Of Chuanxiao Dong
>> Sent: Wednesday, December 01, 2010 8:49 PM
>> To: linux-mmc@vger.kernel.org
>> Cc: linux-kernel@vger.kernel.org; cjb@laptop.org; arjan@linux.intel.com;
>> alan@linux.intel.com; akpm@linux-foundation.org
>> Subject: [PATCH v4 0/4]implement eMMC4.4 standard HW reset feature
>>
>> Hi,
>>       These are the version 4 patches to implement eMMC4.4 HW reset
>>       feature. Host controller can use this feature by trigger RST_n signal.
>>       To enable this, byte 162 of EXT_CSD register should be set.
>>       HW reset is implemented in mmc core layer and sdhci host layer, and it
>>       will be used after each reading/writing/erasing timeout error occures.
>>
>>       change-log:
>>       This version change the way to detect timeout error conditions. Added a
>>       new routine mmc_handle_timeout_error to do this instead to do this in
>>       mmc_wait_for_req. Each timeout read/write/erase command can use this
>>       routine to do HW reset.
>>
>>       patch1: enable HW reset capability if card support.
>>
>>       patch2: add two new callback to implement HW reset in mmc core layer. In
>>       this patch, routine mmc_handle_timeout_error was added.
>>
>>       patch3: implement hardware_reset callback for sdhci host. A new callback
>>       reset_emmc was defined which will be each sdhci host controller to
>>       implement separately.
>>
>>       patch4: did a HW reset after each read/write/erase command.
>>
>> Thanks
>> Chuanxiao
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
>> the body of a message to majordomo@vger.kernel.org
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>

RE: [PATCH v4 0/4]implement eMMC4.4 standard HW reset feature

[Dong, Chuanxiao]

> -----Original Message-----
> From: kyungmin78@gmail.com [mailto:kyungmin78@gmail.com] On Behalf Of
> Kyungmin Park
> Sent: Tuesday, December 07, 2010 9:34 AM
> To: Dong, Chuanxiao
> Cc: linux-mmc@vger.kernel.org; linux-kernel@vger.kernel.org; cjb@laptop.org;
> arjan@linux.intel.com; alan@linux.intel.com; akpm@linux-foundation.org; Mai,
> Leonard; Arnd Bergmann; Wolfram Sang
> Subject: Re: [PATCH v4 0/4]implement eMMC4.4 standard HW reset feature
> 
> On Tue, Dec 7, 2010 at 1:03 AM, Dong, Chuanxiao
> <chuanxiao.dong@intel.com> wrote:
> > Hello all,
> > How about these patches? It implemented HW reset feature. When card
> occurred a timeout error during reading/writing/erasing, these patches will allow
> driver to reset eMMC card by trigger a HW reset signal.
> > Does anyone have any comments about the implementation of these patches?
> Wolfram and Arnd already pointed out the unsuitable patch headers. Thanks! :)
> 
> Hi,
> I'm not yet find a reason to use this feature. Now it uses the samsung
> and sandisk v4.41 but still no problem.
> I wonder what's the purpose and effect if it uses or not?

This feature will only be used when card occurs a timeout error during reading/writing/erasing.
When host send a command to card, for some reason, if card didn't have any response to host, then host controller will generate a timeout interrupt to indicate this command is timeout.
At this time, card maybe cannot response any command unless be reset. If driver did nothing at such scenario, RFC may be crashed. So I think when timeout error occurs, reset card is needed.
Host sends CMD0 also can reset the card, but card may be dead and cannot response any command. So this patch will pull up a GPIO line to trigger a reset signal and let eMMC card reset itself, not send a command to do that.
That is my understanding of this feature.

Thanks
Chuanxiao