I believe this is the reference that Stuart refers to in the ATA-6 spec: http://www.t10.org/t13/project/d1410r3a-ATA-ATAPI-6.pdf Here's the snippet, (p327): " Transition D0HR1:D0HR1: When the sample indicates that DASP- is negated and less than 450 ms have elapsed since the negation of RESET-, then the device shall make a transition to the D0HR1: Sample_DASP- state. When the sample indicates that DASP- is negated and greater than 450 ms but less than 5 s have elapsed since the negation of RESET-, then the device may make a transition to the D0HR1: Sample_DASP- state. Transition D0HR1:D0HR3: When the sample indicates that DASP- is negated and 5 s have elapsed since the negation of RESET-, then the device shall clear bit 7 in the Error register and make a transition to the D0HR3: Set_status state. When the sample indicates that DASP- is negated and greater than 450 ms but less than 5 s have elapsed since the negation of RESET-, then the device may clear bit 7 in the Error register and make a transition to the D0HR3: Set_status state. " Hayes, Stuart wrote: > This fixes problems during resume with drives that take longer than 1s > to be ready. The ATA-6 spec appears to allow 5 seconds for a drive to > be ready. > > On one affected system, this patch changes "PM: resume devices took..." > message from 17 seconds to 4 seconds, and gets rid of a lot of ugly > timeout/error messages. > > Without this patch, the libata code moves on after 1s, tries to send a > soft reset (which the drive doesn't see because it isn't ready) which > also times out, then an IDENTIFY command is sent to the drive which > times out, and finally the error handler will try to send another hard > reset which will finally get things working. > > Sorry to send as an attachment, but my mail server will wrap text. > > > Signed-off-by: Stuart Hayes <stuart_hayes@xxxxxxxx> > > -- Mario Limonciello *Dell | Linux Engineering* mario_limonciello@xxxxxxxx
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