On 2011-05-09 16:31, Alexander Graf wrote: > On 05/09/2011 04:26 PM, Kevin Wolf wrote: >> Am 09.05.2011 16:12, schrieb Alexander Graf: >>> On 05/08/2011 09:10 PM, Jan Kiszka wrote: >>>> Hi Alex, >>>> >>>> I've seen crashes caused by ahci_check_cmd_bh unregistering a NULL bh. >>>> It looks like ahci_dma_set_inactive can a called while there is already >>>> a bh hanging around. Patch below cures the issue, but I have no clue if >>>> such an invocation order is valid at all. >>> It's certainly guest triggerable, so yes, let's check here. >>> >>> Acked-by: Alexander Graf<ag...@suse.de> >> Yes, the change makes sense to me. Please resend this as a proper patch, >> Jan.
Will do. >> >> However, I still think Jan's question is valid: Is the AHCI emulation >> supposed to run multiple DMA requests at once using the core.c >> functions? I'd find it surprising if this actually worked well. > > Not through the IDE core, no. There it can process a queue of IDE > commands after each other or do NCQ, but that goes a different code > patch, can do multiple requests at once though. > > I'm not sure how this got triggered. Forgot to mention: With a hacked-up q35 series. I may have broken something there, or it was already broken (there are definitely bugs in that series), so upstream might not expose the problem at all. Jan -- Siemens AG, Corporate Technology, CT T DE IT 1 Corporate Competence Center Embedded Linux
