From 4bca3286433585b5f1c3e7d8ac37a2f4b3def9ca Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Fri, 15 May 2009 00:40:35 -0400 Subject: libata: Media rotation rate and form factor heuristics This patch provides new heuristics for parsing both the form factor and media rotation rate ATA IDENFITY words. The reported ATA version must be 7 or greater and the device must return values defined as valid in the standard. Only then are the characteristics reported to SCSI via the VPD B1 page. This seems like a reasonable compromise to me considering that we have been shipping several kernel releases that key off the rotation rate bit without any version checking whatsoever. With no complaints so far. Signed-off-by: Martin K. Petersen Signed-off-by: Jeff Garzik --- include/linux/ata.h | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) (limited to 'include/linux/ata.h') diff --git a/include/linux/ata.h b/include/linux/ata.h index cb79b7a208e1..915da43edee1 100644 --- a/include/linux/ata.h +++ b/include/linux/ata.h @@ -730,6 +730,34 @@ static inline int ata_id_has_unload(const u16 *id) return 0; } +static inline int ata_id_form_factor(const u16 *id) +{ + u16 val = id[168]; + + if (ata_id_major_version(id) < 7 || val == 0 || val == 0xffff) + return 0; + + val &= 0xf; + + if (val > 5) + return 0; + + return val; +} + +static inline int ata_id_rotation_rate(const u16 *id) +{ + u16 val = id[217]; + + if (ata_id_major_version(id) < 7 || val == 0 || val == 0xffff) + return 0; + + if (val > 1 && val < 0x401) + return 0; + + return val; +} + static inline int ata_id_has_trim(const u16 *id) { if (ata_id_major_version(id) >= 7 && -- cgit v1.2.3-58-ga151