Re: [PATCH] Re: [git patches] libata updates - (improve post-resetdevice ready test) regression

From: Jeff Garzik
Date: Fri May 09 2008 - 00:37:44 EST


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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