From: Christian Lamparter <chunkeey@xxxxxx> There is another outstanding issue with ata_piix.c. Intel has never officially supported anything faster than PATA 100MB/s. But, the ata_piix.c driver "define" the ICH5 & ICH7 as UDMA6 (aka 133MB/s) capable. [ Well, no one has probably noticed it before, because there is bug in do_pata_set_dmamode... Just look at libata_atapiix_enable_real_udma133.patch and you'll see what wrong with it. ] Here are Intel's datasheets for the affected chipsets: ICH5 Datasheet: http://www.intel.com/design/chipsets/datashts/252516.htm (See note on page 183: "... the ICH5 supports reads at the maximum rate of 100MB/s.") ICH7 Datasheet: http://www.intel.com/design/chipsets/datashts/307013.htm (See first note on page 190: "... the ICH7 supports reads at the maximum rate of 100MB/s.") They are two different ways to deal with it: - Either - 1. replace all ich_pata_133 with ich_pata_100. (libata_atapiix_disable_udma6.diff - diff from 2.6.22 ) - Or - 2. keep all ich_pata_133 and fix the bug in "do_pata_set_dmamode". (libata_atapiix_enable_real_udma133.patch - diff from 2.6.22) If there are any concerns about the safety of the patch patch: http://lkml.org/lkml/2007/7/6/292 (It was already tested by an Intel employee, but I guess a bit more user input is necessary here... ) This patch implements 1. Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> Cc: Jeff Garzik <jeff@xxxxxxxxxx> Cc: Tejun Heo <htejun@xxxxxxxxx> Signed-off-by: Christian Lamparter <chunkeey@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/ata/ata_piix.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) diff -puN drivers/ata/ata_piix.c~ata_piix-disallow-udma-133-on-ich5-ich7 drivers/ata/ata_piix.c --- a/drivers/ata/ata_piix.c~ata_piix-disallow-udma-133-on-ich5-ich7 +++ a/drivers/ata/ata_piix.c @@ -123,7 +123,7 @@ enum { ich_pata_33 = 1, /* ICH up to UDMA 33 only */ ich_pata_66 = 2, /* ICH up to 66 Mhz */ ich_pata_100 = 3, /* ICH up to UDMA 100 */ - ich_pata_133 = 4, /* ICH up to UDMA 133 */ + /* ICH up to UDMA 133 is not supported */ ich5_sata = 5, ich6_sata = 6, ich6_sata_ahci = 7, @@ -198,7 +198,7 @@ static const struct pci_device_id piix_p { 0x8086, 0x24CA, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich_pata_100 }, { 0x8086, 0x24CB, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich_pata_100 }, /* Intel ICH5 */ - { 0x8086, 0x24DB, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich_pata_133 }, + { 0x8086, 0x24DB, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich_pata_100 }, /* C-ICH (i810E2) */ { 0x8086, 0x245B, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich_pata_100 }, /* ESB (855GME/875P + 6300ESB) UDMA 100 */ @@ -206,7 +206,7 @@ static const struct pci_device_id piix_p /* ICH6 (and 6) (i915) UDMA 100 */ { 0x8086, 0x266F, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich_pata_100 }, /* ICH7/7-R (i945, i975) UDMA 100*/ - { 0x8086, 0x27DF, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich_pata_133 }, + { 0x8086, 0x27DF, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich_pata_100 }, { 0x8086, 0x269E, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich_pata_100 }, /* ICH8 Mobile PATA Controller */ { 0x8086, 0x2850, PCI_ANY_ID, PCI_ANY_ID, 0, 0, ich_pata_100 }, @@ -489,7 +489,7 @@ static struct ata_port_info piix_port_in .port_ops = &ich_pata_ops, }, - /* ich_pata_133: 4 ICH with full UDMA6 */ + /* ich_pata_133: 4 - Not supported - */ { .sht = &piix_sht, .flags = PIIX_PATA_FLAGS | PIIX_FLAG_CHECKINTR, _ - 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
