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Stefan Richter authored
Since commit bd972688 "firewire: ohci: Fix 'failed to read phy reg' on FW643 rev8", there is a high chance that firewire-ohci fails to initialize LSI née Agere controllers. https://bugzilla.kernel.org/show_bug.cgi?id=65151 Peter Hurley points out the reason: IEEE 1394a:2000 clause 5A.1 (or IEEE 1394:2008 clause 17.2.1) say: "The PHY shall insure that no more than 10 ms elapse from the reassertion of LPS until the interface is reset. The link shall not assert LReq until the reset is complete." In other words, the link needs to give the PHY at least 10 ms to get the interface operational. With just the msleep(1) in bd972688, the first read_phy_reg() during ohci_enable() may happen before the phy-link interface reset was finished, and fail. Due to the high variability of msleep(n) with small n, this failure was not fully reproducible, and not apparent at all with low CONFIG_HZ setting. On the other hand, Peter can no longer reproduce the issue with FW643 rev8. The read phy reg failures that happened back then may have had an unrelated cause. So, just revert bd972688, except for the valid comment on TSB82AA2 cards. Reported-by: Mikhail Gavrilov Reported-by: Jay Fenlason <fenlason@redhat.com> Reported-by: Clemens Ladisch <clemens@ladisch.de> Reported-by: Peter Hurley <peter@hurleysoftware.com> Cc: stable@vger.kernel.org # v3.10+ Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
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