Messages in this thread | | | Date | Tue, 15 Nov 2005 09:11:14 -0500 | From | Jeff Garzik <> | Subject | Re: [PATCH] libata error handling fixes (ATAPI) |
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Tejun Heo wrote: > * prb->fis doesn't contain proper signature after phy reset. I just
This makes sense. Each PRB slot in the card's RAM only contains something useful after you have submitted a PRB, and had some results returned.
> * As all commands hang after failed TUR, which BTW fails rightfully with > 06h (UNIT ATTENTION due to prior reset) and then 02h's (NOT READY), I > avoided TUR failures by issuing REQUEST SENSE first, which returns NO > SENSE but does clear UA condition, and then waiting for more than 10secs > to give the drive time to become ready.
10 seconds is certainly a long time.
grep for msleep(150) in libata code, though.
> * With above two changes, no command fails and I can mount the cdrom. > > ------------------ > > And here are things that I've found out so far.... > > * ATAPI commands without data (TEST_UNIT_READY, ALLOW_MEDIUM_REMOVAL...) > work happily with any prb->ctrl flag (no flag, PRB_CTRL_PACKET_READ or > PRB_CTRL_PACKET_WRITE).
I suppose no-flag is the right answer, then...
> * Currently, sil24_reset_controller() is called on every error interrupt > to make sure the controller is ready for further operation. > Unfortunately, the current reset_controller() seems to reset PHY too. > The drive becomes NOT READY after reset_controller(). So, when TUR > fails, it falls into TUR, fail with NOT READY, reset which makes the > drive NOT READY again cycle.
Standard init sequence includes checking SStatus, then if a device is present, waiting until Port Ready (bit 31) of PORT_CTRL_STAT is set. It doesn't look like sata_sil24 does that.
> * Wihtout sil24_reset_controller(), no further command can be issued. > The controller doesn't seem to be operating normally after DEV_ERR.
The port stops, when any error occurs. For device errors, set PORT_CS_INIT bit in PORT_CTRL_STAT, then wait for Port Ready (bit 31, see above).
> So, what we need to know to make sil24 work happily with ATAPI devices. > > * How to get device signature on initialization.
AFAICS, you _must_ send a soft reset PRB. This will be needed anyway, for port multiplier support.
> * How to make the controller operational again after a DEV_ERR without > affecting the attached device.
Assert PORT_CS_INIT, then wait for Port Ready. __ONLY__ do this for errors PORT_CERR_DEV and PORT_CERR_SDB.
Jeff
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