Re: power class selection fails on 3.5-rc1

[Ulf Hansson <ulf.hansson@stericsson.com>]

Hi Marc,

Maybe we can have some input from Subhash on this matter. I believe a 
revert can be feasible until a working solution exist.

Kind regards
Ulf Hansson

On 06/04/2012 06:35 PM, Marc Dietrich wrote:
> Hi,
>
> somehow I hope this would go away by itself, but it didn't :-( I reported this
> problem some time ago (see: http://www.mail-archive.com/linux-
> mmc@vger.kernel.org/msg13688.html ) but got no clear answer or fix.
>
> In addition to the information I posted on the thread above, I also dumped the
> contents of the ext_csd register file (where reg values are not zero):
>
> reg       Sandisk         Toshiba
> 241     10      0x0a    50      0x32
> 239     0       0x00    51      0x33
> 238     0       0x00    119     0x77
> 234     0       0x00    30      0x1e
> 232     1       0x01    4       0x04
> 231     21      0x15    21      0x15
> 230     150     0x96    16      0x10
> 229     150     0x96    66      0x42
> 228     1       0x01    7       0x07
> 226     8       0x08    16      0x10
> 225     6       0x06    7       0x07
> 224     4       0x04    8       0x08
> 223     1       0x01    2       0x02
> 222     8       0x08    16      0x10
> 221     16      0x10    1       0x01
> 220     8       0x08    7       0x07
> 219     7       0x07    7       0x07
> 217     16      0x10    17      0x11
> 215     1       0x01    0       0x00
> 214     218     0xda    238     0xee
> 213     160     0xa0    128     0x80
> 210     10      0x0a    0       0x00
> 209     10      0x0a    60      0x3c
> 208     10      0x0a    0       0x00
> 207     10      0x0a    60      0x3c
> 206     10      0x0a    0       0x00
> 205     10      0x0a    30      0x1e
> 203     0       0x00    51      0x33
> 202     0       0x00    51      0x33
> 201     0       0x00    119     0x77
> 200     0       0x00    119     0x77
> 196     3       0x03    7       0x07
> 194     2       0x02    2       0x02
> 192     5       0x05    5       0x05
> 185     1       0x01    1       0x01
> 181     0       0x00    1       0x01
> 179     0       0x00    1       0x01
> 175     0       0x00    1       0x01
> 169     1       0x01    0       0x00
> 168     0       0x00    2       0x02
> 160     3       0x03    3       0x03
> 158     0       0x00    3       0x03
> 157     237     0xed    186     0xba
>
> The second and the third column is from a device with a Sandisk eMCC which
> works fine, while the last two columns are from a Toshiba eMMC which shows the
> error. Looking into it, I found that only the Toshiba eMMC specifies a
> powerclass in registers 203-200 while Sandisk does not, so the powerclass is
> not changed in the latter case and the problem cannot be triggered there.
>
> I also attached a boot log with mmc debug enabled. I think there is not much I
> can do else. Either this eMMC is just bogus and needs blacklisting or there is
> some problem in the driver code.
>
> I hope this problem can be fixed or if it can't, I hope that commit 3d93576e
> (mmc: core: skip card initialization if power class selection fails) is
> reverted until the issues are sorted out.
>
> Greetings,
>
> 	Marc