On Tue, May 01, 2007 at 05:02:22AM +0200, Tejun Heo wrote: > Hello, Art Haas. > > Art Haas wrote: > > Hi. > > > > Back in the beginning of February I was sent a patch to test during the > > time the CD-ROM identification bug was affecting my computer. The > > first posting of the patch appeared on Feb. 3 with Tejun Heo writing: > > Ah.. I completely forgot about this one. This wasn't directly related > to the detection bug, so I got oblivious as usual. :-) > > I think Alan has reviewed it back then. If there's no objection, I'll > reformat the patch and submit it properly. Quoting whole message for Jeff. > > >> Hello, Art Haas, Alan. > >> > >> Okay, here's another try at fixing the detection bug. I went through > >> intel ich docs and compared with the ide piix driver. This patch > >> fixes the following problems. > >> > >> * Control bits in the timing register wasn't cleared properly while > >> programming PIO mode. > >> > >> * MWDMA mode programming cleared the wrong part of control bits. I > >> think this can fix your problem. > >> > >> * MWDMA mode programming cleared udma_mask even when the controller > >> doesn't support UDMA. This doesn't matter for your case. > >> > >> Please test and report the result. Thanks. > > > > The patch and complete thread can be reviewed here: > > > > http://marc.info/?l=linux-ide&m=117042956705812&w=2 > > > > Now that 2.6.22 is open for big modifications, and the queued libata > > changes have been pulled by Linus, I'm wondering if the ata_piix.c patch > > posted above should be sent. I've built all my kernels since the posting > > with the patch and had no problems. As you write above, the patch does > > fix some bugs, and as the thread progressed a cleanup or two in the code > > was explained as a bug fix - the setting of the 'slave_data' variable > > between lines 826 and 834 in particular. > > > > Here's the patch against today's Linus tree if you feel it should make > > it into 2.6.22. > > [ ... snip ... ] Ping? Here's the patch diffed to this afternoon's tree. Art Haas diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c index 0458811..51de738 100644 --- a/drivers/ata/ata_piix.c +++ b/drivers/ata/ata_piix.c @@ -684,8 +684,14 @@ static void piix_set_piomode (struct ata_port *ap, struct ata_device *adev) if (adev->class == ATA_DEV_ATA) control |= 4; /* PPE enable */ + /* PIO configuration clears DTE unconditionally. It will be + * programmed in set_dmamode which is guaranteed to be called + * after set_piomode if any DMA mode is available. + */ pci_read_config_word(dev, master_port, &master_data); if (is_slave) { + /* clear TIME1|IE1|PPE1|DTE1 */ + master_data &= 0xff0f; /* Enable SITRE (seperate slave timing register) */ master_data |= 0x4000; /* enable PPE1, IE1 and TIME1 as needed */ @@ -693,12 +699,14 @@ static void piix_set_piomode (struct ata_port *ap, struct ata_device *adev) pci_read_config_byte(dev, slave_port, &slave_data); slave_data &= (ap->port_no ? 0x0f : 0xf0); /* Load the timing nibble for this slave */ - slave_data |= ((timings[pio][0] << 2) | timings[pio][1]) << (ap->port_no ? 4 : 0); + slave_data |= ((timings[pio][0] << 2) | timings[pio][1]) + << (ap->port_no ? 4 : 0); } else { - /* Master keeps the bits in a different format */ - master_data &= 0xccf8; + /* clear ISP|RCT|TIME0|IE0|PPE0|DTE0 */ + master_data &= 0xccf0; /* Enable PPE, IE and TIME as appropriate */ master_data |= control; + /* load ISP and RCT */ master_data |= (timings[pio][0] << 12) | (timings[pio][1] << 8); @@ -815,7 +823,7 @@ static void do_pata_set_dmamode (struct ata_port *ap, struct ata_device *adev, i master_data &= 0xFF4F; /* Mask out IORDY|TIME1|DMAONLY */ master_data |= control << 4; pci_read_config_byte(dev, 0x44, &slave_data); - slave_data &= (0x0F + 0xE1 * ap->port_no); + slave_data &= (ap->port_no ? 0x0f : 0xf0); /* Load the matching timing */ slave_data |= ((timings[pio][0] << 2) | timings[pio][1]) << (ap->port_no ? 4 : 0); pci_write_config_byte(dev, 0x44, slave_data); @@ -827,8 +835,11 @@ static void do_pata_set_dmamode (struct ata_port *ap, struct ata_device *adev, i (timings[pio][0] << 12) | (timings[pio][1] << 8); } - udma_enable &= ~(1 << devid); - pci_write_config_word(dev, master_port, master_data); + + if (ap->udma_mask) { + udma_enable &= ~(1 << devid); + pci_write_config_word(dev, master_port, master_data); + } } /* Don't scribble on 0x48 if the controller does not support UDMA */ if (ap->udma_mask) -- Man once surrendering his reason, has no remaining guard against absurdities the most monstrous, and like a ship without rudder, is the sport of every wind. -Thomas Jefferson to James Smith, 1822 - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
