From: Jens Axboe <jens.axboe@oracle.com>
Date: Wed, 24 Sep 2008 11:05:10 +0000 (+0200)
Subject: libata: set queue SSD flag for SSD devices
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=8bff7c6b0f63c7ee9c5e3a076338d74125b8debb;p=openwrt%2Fstaging%2Fblogic.git

libata: set queue SSD flag for SSD devices

SSD devices should give an RPM setting of 1 in word 217 of the ID
page. If we see such a device, tell the block layer about it.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index b9d3ba423cb2..054370700abf 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -977,6 +977,10 @@ static int ata_scsi_dev_config(struct scsi_device *sdev,
 
 		blk_queue_dma_drain(q, atapi_drain_needed, buf, ATAPI_MAX_DRAIN);
 	} else {
+		if (ata_id_is_ssd(dev->id))
+			queue_flag_set_unlocked(QUEUE_FLAG_NONROT,
+						sdev->request_queue);
+
 		/* ATA devices must be sector aligned */
 		blk_queue_update_dma_alignment(sdev->request_queue,
 					       ATA_SECT_SIZE - 1);
diff --git a/include/linux/ata.h b/include/linux/ata.h
index 8a12d718c169..c1c8b4a4ba26 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -88,6 +88,7 @@ enum {
 	ATA_ID_DLF		= 128,
 	ATA_ID_CSFO		= 129,
 	ATA_ID_CFA_POWER	= 160,
+	ATA_ID_ROT_SPEED	= 217,
 	ATA_ID_PIO4		= (1 << 1),
 
 	ATA_ID_SERNO_LEN	= 20,
@@ -691,6 +692,11 @@ static inline int ata_id_is_cfa(const u16 *id)
 	return 0;
 }
 
+static inline int ata_id_is_ssd(const u16 *id)
+{
+	return id[ATA_ID_ROT_SPEED] == 0x01;
+}
+
 static inline int ata_drive_40wire(const u16 *dev_id)
 {
 	if (ata_id_is_sata(dev_id))