Commit ffa29456 authored by Alan Cox's avatar Alan Cox Committed by Jeff Garzik

[PATCH] libata: Pre UDMA EIDE PIO mode selection

I misread the spec when doing the original. I've tested the corrected
version with pre UDMA drives and it now picks the right modes. This is a
specific bug fix rather than an update or new feature item.
Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarJeff Garzik <jgarzik@pobox.com>
parent 5a46fe89
...@@ -1051,18 +1051,22 @@ static unsigned int ata_pio_modes(const struct ata_device *adev) ...@@ -1051,18 +1051,22 @@ static unsigned int ata_pio_modes(const struct ata_device *adev)
{ {
u16 modes; u16 modes;
/* Usual case. Word 53 indicates word 88 is valid */ /* Usual case. Word 53 indicates word 64 is valid */
if (adev->id[ATA_ID_FIELD_VALID] & (1 << 2)) { if (adev->id[ATA_ID_FIELD_VALID] & (1 << 1)) {
modes = adev->id[ATA_ID_PIO_MODES] & 0x03; modes = adev->id[ATA_ID_PIO_MODES] & 0x03;
modes <<= 3; modes <<= 3;
modes |= 0x7; modes |= 0x7;
return modes; return modes;
} }
/* If word 88 isn't valid then Word 51 holds the PIO timing number /* If word 64 isn't valid then Word 51 high byte holds the PIO timing
for the maximum. Turn it into a mask and return it */ number for the maximum. Turn it into a mask and return it */
modes = (2 << (adev->id[ATA_ID_OLD_PIO_MODES] & 0xFF)) - 1 ; modes = (2 << ((adev->id[ATA_ID_OLD_PIO_MODES] >> 8) & 0xFF)) - 1 ;
return modes; return modes;
/* But wait.. there's more. Design your standards by committee and
you too can get a free iordy field to process. However its the
speeds not the modes that are supported... Note drivers using the
timing API will get this right anyway */
} }
struct ata_exec_internal_arg { struct ata_exec_internal_arg {
......
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