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| author | Alan Cox <alan@lxorguk.ukuu.org.uk> | 2007-08-08 14:27:00 +0100 |
|---|---|---|
| committer | Jeff Garzik <jeff@garzik.org> | 2007-10-12 14:55:32 -0400 |
| commit | 50a99018787aa1aed812e09ad5b27647475656a0 (patch) | |
| tree | 371cfd54028da85abc8313cd72501541f7c6f06d /drivers/ata/libata-core.c | |
| parent | baf4fdfaaf5cb9f4fb1c341c8cef60a64e580582 (diff) | |
| download | linux-50a99018787aa1aed812e09ad5b27647475656a0.tar.bz2 | |
libata-core: Document some limits/assumptions about ID_ATA
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers/ata/libata-core.c')
| -rw-r--r-- | drivers/ata/libata-core.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index 75ccf46972d8..d2141a04fff1 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -1618,6 +1618,9 @@ static u32 ata_pio_mask_no_iordy(const struct ata_device *adev) * devices. This function also issues ATA_CMD_INIT_DEV_PARAMS * for pre-ATA4 drives. * + * FIXME: ATA_CMD_ID_ATA is optional for early drives and right + * now we abort if we hit that case. + * * LOCKING: * Kernel thread context (may sleep) * @@ -1745,10 +1748,13 @@ int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class, /* * The exact sequence expected by certain pre-ATA4 drives is: * SRST RESET - * IDENTIFY - * INITIALIZE DEVICE PARAMETERS + * IDENTIFY (optional in early ATA) + * INITIALIZE DEVICE PARAMETERS (later IDE and ATA) * anything else.. * Some drives were very specific about that exact sequence. + * + * Note that ATA4 says lba is mandatory so the second check + * shoud never trigger. */ if (ata_id_major_version(id) < 4 || !ata_id_has_lba(id)) { err_mask = ata_dev_init_params(dev, id[3], id[6]); |