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. > > Art Haas > > diff --git a/drivers/ata/ata_piix.c b/drivers/ata/ata_piix.c > index 55d306a..26c8b5f 100644 > --- a/drivers/ata/ata_piix.c > +++ b/drivers/ata/ata_piix.c > @@ -695,8 +695,14 @@ 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 */ > @@ -704,12 +710,14 @@ 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); > @@ -826,7 +834,7 @@ 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); > @@ -838,8 +846,11 @@ 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) > -- tejun - 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
