Messages in this thread | | | Date | Fri, 09 May 2008 00:37:00 -0400 | From | Jeff Garzik <> | Subject | Re: [PATCH] Re: [git patches] libata updates - (improve post-reset device ready test) regression |
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Tejun Heo wrote: > This means that we need to make custom readiness tests for controllers > using 0x77 or 0x7f. Eeeek... Both groups of controllers are behaving in > incorrect way. Controllers shouldn't use 0x77 or 0x7f for either busy > or ready states - it's invalid for both, yet, some use the 77/7f for > busy while others use them for ready state. Great. :-(
I think that's assuming too much? PATA and SATA are quite different here... in PATA the status is mostly the value from the device directly off the wires. in SATA, it may be from the device or from the controller. And "smart" or firmware-based controllers may generate their own status, too, apart from the device's status.
So that results in varied status returns, and not all the time is a definite "ready" or "not ready" obvious.
Jeff
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