Art Haas wrote:
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)
Please resend with proper sign-offs. All patches in the kernel need
that... http://linux.yyz.us/patch-format.html
Thanks,
Jeff
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