2012-11-22 20:56:33

by Chris Ball

[permalink] [raw]
Subject: Re: [PATCH] mmc: Added quirks for Ricoh 1180:e823 lower base clock frequency

Hi Manoj, Matsumuro-san,

On Mon, Jul 18 2011, Manoj Iyer wrote:
> Right, without the patch I get..
>
> [ 52.526665] mmc0: new SDHC card at address e624
> [ 52.571228] mmcblk0: mmc0:e624 SD16G 14.8 GiB
> [ 52.591071] mmcblk0: retrying using single block read
> [ 52.593105] mmcblk0: error -84 transferring data, sector 0, nr 8,
> card status 0x900
> [ 52.593109] end_request: I/O error, dev mmcblk0, sector 0
> [ 52.594594] mmcblk0: error -84 transferring data, sector 1, nr 7,
> card status 0x900
> [ 52.594604] end_request: I/O error, dev mmcblk0, sector 1
> [ 52.602893] quiet_error: 24 callbacks suppressed
> [ 52.602902] Buffer I/O error on device mmcblk0, logical block 0
> [ 52.605349] ldm_validate_partition_table(): Disk read failed.
> [ 52.605384] Dev mmcblk0: unable to read RDB block 0
> [ 52.607729] mmcblk0: unable to read partition table
> u@u:~$
>
> So, I cannot generate any comparison data with this SD card.

I don't know if you remember this bug, but I have reports from two users
who see "error -84"s on :e823 controllers even with this patch active on
modern ThinkPads.

Maybe 50MHz isn't low enough sometimes? Is it possible to lower the base
clock further?

I noticed that the frequency is encoded ine one of the PCI writes:
+ * 0x32 - 50Mhz new clock frequency

So if I get access to one of these systems, I might try lowering that
value (by half, say) and see what happens. But at the moment I haven't
found someone who's willing to try kernel patches yet, and I don't have
one of these systems myself.

Thanks!

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


2012-11-26 16:43:08

by Manoj Iyer

[permalink] [raw]
Subject: Re: [PATCH] mmc: Added quirks for Ricoh 1180:e823 lower base clock frequency


Chris,

Do you know what systems produce these errors? I can look and see if we
have those for testing your patch.

Cheers
Manoj

On Wed, 21 Nov 2012, Chris Ball wrote:

> Hi Manoj, Matsumuro-san,
>
> On Mon, Jul 18 2011, Manoj Iyer wrote:
>> Right, without the patch I get..
>>
>> [ 52.526665] mmc0: new SDHC card at address e624
>> [ 52.571228] mmcblk0: mmc0:e624 SD16G 14.8 GiB
>> [ 52.591071] mmcblk0: retrying using single block read
>> [ 52.593105] mmcblk0: error -84 transferring data, sector 0, nr 8,
>> card status 0x900
>> [ 52.593109] end_request: I/O error, dev mmcblk0, sector 0
>> [ 52.594594] mmcblk0: error -84 transferring data, sector 1, nr 7,
>> card status 0x900
>> [ 52.594604] end_request: I/O error, dev mmcblk0, sector 1
>> [ 52.602893] quiet_error: 24 callbacks suppressed
>> [ 52.602902] Buffer I/O error on device mmcblk0, logical block 0
>> [ 52.605349] ldm_validate_partition_table(): Disk read failed.
>> [ 52.605384] Dev mmcblk0: unable to read RDB block 0
>> [ 52.607729] mmcblk0: unable to read partition table
>> u@u:~$
>>
>> So, I cannot generate any comparison data with this SD card.
>
> I don't know if you remember this bug, but I have reports from two users
> who see "error -84"s on :e823 controllers even with this patch active on
> modern ThinkPads.
>
> Maybe 50MHz isn't low enough sometimes? Is it possible to lower the base
> clock further?
>
> I noticed that the frequency is encoded ine one of the PCI writes:
> + * 0x32 - 50Mhz new clock frequency
>
> So if I get access to one of these systems, I might try lowering that
> value (by half, say) and see what happens. But at the moment I haven't
> found someone who's willing to try kernel patches yet, and I don't have
> one of these systems myself.
>
> Thanks!
>
> - Chris.
> --
> Chris Ball <[email protected]> <http://printf.net/>
> One Laptop Per Child
>
>

--
====================
Manoj Iyer
Ubuntu/Canonical
Hardware Enablement
====================

2012-11-26 16:57:55

by Chris Ball

[permalink] [raw]
Subject: Re: [PATCH] mmc: Added quirks for Ricoh 1180:e823 lower base clock frequency

Hi Manoj,

On Mon, Nov 26 2012, Manoj Iyer wrote:
> Do you know what systems produce these errors? I can look and see if
> we have those for testing your patch.

One T430s using the ExpressCard reader¹, and one X220, both with :e823.

Thanks,

- Chris.

¹: http://support.lenovo.com/en_US/product-and-parts/detail.page?&DocID=PD023556
--
Chris Ball <[email protected]> <http://printf.net/>
One Laptop Per Child