Re: [PATCH 1/4] ide: add ide_dev_is_sata() helper
From: Sergei Shtylyov <hidden>
Date: 2007-08-24 18:46:48
Also in:
lkml
Hello, I wrote:
Make the SATA drive detection code from eighty_ninty_three() into inline ide_dev_is_sata() helper fixing it along the way to be more strict while checking word 80 for the reserved values...
Signed-off-by: Sergei Shtylyov <redacted>
[...]
quoted hunk ↗ jump to hunk
Index: linux-2.6/drivers/ide/ide-iops.c ===================================================================--- linux-2.6.orig/drivers/ide/ide-iops.c +++ linux-2.6/drivers/ide/ide-iops.c@@ -580,8 +580,7 @@ u8 eighty_ninty_three (ide_drive_t *driv if (hwif->cbl != ATA_CBL_PATA80) goto no_80w; - /* Check for SATA but only if we are ATA5 or higher */ - if (id->hw_config == 0 && (id->major_rev_num & 0x7FE0)) + if (ide_dev_is_sata(id)) return 1; /*Index: linux-2.6/include/linux/ide.h ===================================================================--- linux-2.6.orig/include/linux/ide.h +++ linux-2.6/include/linux/ide.h@@ -1380,6 +1380,19 @@ static inline int ide_dev_has_iordy(stru return ((id->field_valid & 2) && (id->capability & 8)) ? 1 : 0; } +static inline int ide_dev_is_sata(struct hd_driveid *id) +{ + /* + * See if word 93 is 0 AND drive is at least ATA-5 compatible + * making sure that word 80 is valid by flipping its MSB -- + * this trick allows us to filter out reserved values of 0 + * and 0xffff along with the earlier ATA revisions. + */ + if (id->hw_config == 0 && (id->major_rev_num ^ 0x8000) >= 0x8020) + return 1; + return 0; +} +
The same could have been achieved more simply:
if (id->hw_config == 0 && (short}id->major_rev_num >= 0x0020
so I'll probably recast...
MBR, Sergei