Alan Cox wrote: > On Wed, 28 Nov 2007 10:36:15 +0900 > Tejun Heo <htejun@xxxxxxxxx> wrote: > >> Alan Cox wrote: >>> Hopefully there is a better long term solution but for now lets favour >>> reliability. >> I'm getting a lot of reports on pata_ali w/ misc ATAPI commands too. Do >> you know whether it's a controller problem or drive one? All the >> reports I got are laptops and I can't really ask them to disassemble >> their laptops. :-) > > ALi is one that most definitely appears to be controller related. Thats > why I sent Jeff a patch to use DMA for 2K+ transfers only. Some ALi also > required the patch to set the xfer lengths. > > Its only some revs/combinations annoyingly - a lot of them (including the > ones I have direct access too) just work. Does READ_CD work fine via DMA? 2K+ filtering filters most if not all misc commands so usually only sector (2K) aligned READ and WRITEs are done via DMA. Interesting exceptions are READ_CD[_MSF] and READ/WRITE_BUFFER which usually exceed 2K but aren't aligned to 2K. I guess it's about time to write a test case program which issues a bunch of problematic commands and see which works. Thanks. -- tejun - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
