Re: [PATCH] ide: motherboard-info based blacklist for ide-dma

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Hello, I wrote:

>>>>>>> True.  However it should be possible to handle it correctly by 
>>>>>>> adding
>>>>>>> the
>>>>>>> DMA quirk to the respective host drivers (seems to be via82cxxx.c in
>>>>>>> case of
>>>>>>> IEI PCISA-C3/EDEN).

>>>>>>  Yeah, this seems a viable approach...

>>>>>>> Kirill, could you please look into adding such quirk to via82cxxx
>>>>>>> instead?

>>>>>>> [ It seems the best place to add it would be via_init_one() as we
>>>>>>> could just

>>>>>>  No, not really -- the issue is not at all as simple as this patch
>>>>>> tried to present it. Looking at its "Quick Startup Reference"
>>>>>> (http://f.ipc2u.ru/files/add/doc/496/M_PCISA-C800EV_ENG.pdf), the 
>>>>>> EPIC
>>>>>> board has *two* normal IDE connectors in addition to the CF slot
>>>>>> (connected to the secondary port -- and it seems possible that a hard
>>>>>> drive can be connected to the same port as CF), so the right place
>>>>>> seems to rather be in [mu]dma_filter() methods -- and the decision
>>>>>> should be strictly based on the drive type indicating CF, i.e. by
>>>>>> calling ata_id_is_cfa().

>> I have tried my old Trancend 64Mb, RamStar 521Mb and NCP 64Mb cards. 
>> My old cards returned right id[ATA_ID_CONFIG] = 0x848A.

>> But I have to use Kingston CF Card 1Gb 2008.
>> ata_id_is_cfa() returns 0 for it and
>> id[ATA_ID_MAJOR_VER]    = 0
>> id[ATA_ID_CONFIG]        = 0x044A

>    That seems non-standard CF as ATA specifies that it must have 0x848A 
> there.

>> I have only CF+ specification revision 2.0,  but I've found in wiki:
> 
> 
>    Try googling for cfspc_41.pdf (and other versions), you'll be 
> surprised in a good way. ;-)
> 
>> (http://en.wikipedia.org/wiki/CompactFlash#CF.2B_specification_revisions)
>> "... While the current revision 4.1 from 2004 works only in ATA mode, 
>> ..."
> 
> 
>> So I have reached an impasse. How to identify modern CF cards?

>    Hm, I should consult the specs...

    ATA/PI-7 rev. 4b has this in 4.10:

Devices reporting the value 848Ah in IDENTIFY DEVICE data word 0 or devices 
having bit 2 of IDENTIFY DEVICE data word 83 set to one shall support the CFA 
feature Set. If the CFA feature set is implemented, all five commands shall be 
implemented.

    Alan, looks like the libata's CF criterion needs to be enhanced.

MBR, Sergei