2010-11-18 09:02:22

by Chuanxiao Dong

[permalink] [raw]
Subject: [PATCH v2 0/3]mmc: set a suitable max_discard_sectors value for HC

Hello Chris,
These are the version 2 patches of setting a suitable
max_discard_sectors value for sdhci host controller.

The max_discard_sectors determines how many sectors will be passed
down to host controller for erasing. The default value is UNIT_MAX
which means the block layer can pass down unlimited sectors one time
to host controller. But for some kinds of SDHCI host controller, like
MFLD SDHCI host controller cannot erase so many sectors one time. It
will generate a timeout interrupt since the erasing time is longer
than the host controller waiting timeout time. This should be a
hardware architecture issue.

So in these patches, add a new quirk to work around this. The new
quirk can help host controllers to set a safe max_discard_sectors value
for them.

patch1: Add a new quirk for SDHCI host controller and a new mmc
capability which will help mmc core layer to set a suitable
max_discard_sectors value for it.

patch2: Set the sdhci host controller timeout value to be the maximum
one for each erase command. This will be safe for this kind of SDHCI
host controller.

patch3: Add the new quirk to MFLD SDHCI host controller.

Thanks
Chuanxiao


2010-11-30 07:23:48

by Chuanxiao Dong

[permalink] [raw]
Subject: RE: [PATCH v2 0/3]mmc: set a suitable max_discard_sectors value for HC

Hi Chris,
I have submitted several patches to this mail list since Oct.25, but didn't get any response.
Do you have any plan to review them? I would like to fix all of them if you have concern about them.

Below are my patches, but no response got from each since the first submission.
1. eMMC4.4 hardware reset feature, the first submission was at Oct.25. Last patch list:
https://patchwork.kernel.org/patch/334931/
https://patchwork.kernel.org/patch/334941/
2. eMMC4.4 enhanced area feature, the first submission was at Oct.26. Last patch list:
https://patchwork.kernel.org/patch/282052/
3. usage of eMMC trim. This submission is a workaround for some sdhci host controller which cannot erase the whole device at one time. The first submission was at Nov.11. Last patch list:
https://patchwork.kernel.org/patch/335361/
https://patchwork.kernel.org/patch/335381/
https://patchwork.kernel.org/patch/335411/

I expect any comment from all of you.

Thanks
Chuanxiao

> -----Original Message-----
> From: [email protected]
> [mailto:[email protected]] On Behalf Of Chuanxiao Dong
> Sent: Thursday, November 18, 2010 5:00 PM
> To: [email protected]
> Cc: [email protected]; [email protected];
> [email protected]; [email protected]
> Subject: [PATCH v2 0/3]mmc: set a suitable max_discard_sectors value for HC
>
> Hello Chris,
> These are the version 2 patches of setting a suitable
> max_discard_sectors value for sdhci host controller.
>
> The max_discard_sectors determines how many sectors will be passed
> down to host controller for erasing. The default value is UNIT_MAX
> which means the block layer can pass down unlimited sectors one time
> to host controller. But for some kinds of SDHCI host controller, like
> MFLD SDHCI host controller cannot erase so many sectors one time. It
> will generate a timeout interrupt since the erasing time is longer
> than the host controller waiting timeout time. This should be a
> hardware architecture issue.
>
> So in these patches, add a new quirk to work around this. The new
> quirk can help host controllers to set a safe max_discard_sectors value
> for them.
>
> patch1: Add a new quirk for SDHCI host controller and a new mmc
> capability which will help mmc core layer to set a suitable
> max_discard_sectors value for it.
>
> patch2: Set the sdhci host controller timeout value to be the maximum
> one for each erase command. This will be safe for this kind of SDHCI
> host controller.
>
> patch3: Add the new quirk to MFLD SDHCI host controller.
>
> Thanks
> Chuanxiao
> --
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> More majordomo info at http://vger.kernel.org/majordomo-info.html

2010-11-30 15:59:12

by Chris Ball

[permalink] [raw]
Subject: Re: [PATCH v2 0/3]mmc: set a suitable max_discard_sectors value for HC

Hi Chuanxiao,

On Tue, Nov 30, 2010 at 03:21:15PM +0800, Dong, Chuanxiao wrote:
> I have submitted several patches to this mail list since Oct.25, but didn't get any response.
> Do you have any plan to review them? I would like to fix all of them if you have concern about them.

Thank you for the patches, I'm sorry you didn't get a reply yet. We will
review all of them. (I'm not expert with eMMC yet, so it would be better
for someone else on the list to review those patches if possible.)

Thanks!

--
Chris Ball <[email protected]> <http://printf.net/>
One Laptop Per Child

2010-12-01 01:04:12

by Chuanxiao Dong

[permalink] [raw]
Subject: RE: [PATCH v2 0/3]mmc: set a suitable max_discard_sectors value for HC

>
> Thank you for the patches, I'm sorry you didn't get a reply yet. We will
> review all of them. (I'm not expert with eMMC yet, so it would be better
> for someone else on the list to review those patches if possible.)

Thanks for your explanation, Chris. I will wait for any response. If I have any update for these patches from myself, I will also resubmit them.
Thanks again.

--Chuanxiao