Tejun Heo wrote:
P5W-DH Deluxe has ICH9 which doesn't have PMP support but SIMG 4726 hardwired to the second port of AHCI controller at PCI device 1f.2. The 4726 doesn't work as PMP but as a storage processor which can do hardware RAID on downstream ports. When no device is attached to the downstream port of the 4726, pseudo ATA device for configuration appears. Unfortunately, ATA emulation on the device is very lousy and causes long hang during boot. This patch implements workaround for the board. If the mainboard is P5W-DH Deluxe (matched using DMI), only hardreset is used on the second port of AHCI controller @ 1f.2 and the hardreset doesn't depend on receiving the first FIS and just proceed to IDENTIFY. This workaround fixes bugzilla #8923. http://bugzilla.kernel.org/show_bug.cgi?id=8923 Signed-off-by: Tejun Heo <htejun@xxxxxxxxx> --- Okay, here's improved version. p5wdh hardreset is sufficiently different from vt8251, so it now has its own hardreset and ops. It now also has two secs + 150ms delay after hardreset so that devices which are slow to respond after hardreset don't fail. Most devices will respond in time unless it's spinning up. Spin up is handled by reset retrials. Also, it sets BSY before initiating BSY and performs CLO afterward if BSY isn't cleared during the wait. Change from the first take are minor but make the workaoround fit the problem better. Tested on a setup which behaves the same way as P5W-DH (non-PMP capable ICH AHCI + SIMG 4726) with some number of harddrives and ATAPI devices. Everything including hotplug works fine. drivers/ata/ahci.c | 144 +++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 144 insertions(+)
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