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authorTejun Heo <htejun@gmail.com>2007-03-28 18:33:39 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2007-04-06 03:43:17 -0700
commit59e23e6198366f057ea49127f810098424d3417c (patch)
tree586a5613ed520f66926e560d3055e80836f03eb7
parent46113c80a92c0bd9ccc7be765e3d487e3e86dac0 (diff)
downloadlinux-linaro-stable-59e23e6198366f057ea49127f810098424d3417c.tar.gz
libata: clear TF before IDENTIFYing
libata: clear TF before IDENTIFYing Some devices chock if Feature is not clear when IDENTIFY is issued. Set ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE for IDENTIFY such that whole TF is cleared when reading ID data. Kudos to Art Haas for testing various futile patches over several months and Mark Lord for pointing out the fix. Signed-off-by: Tejun Heo <htejun@gmail.com> Cc: Art Haas <ahaas@airmail.net> Cc: Mark Lord <mlord@pobox.com> Cc: Chuck Ebbert <cebbert@redhat.com> Signed-off-by: Jeff Garzik <jeff@garzik.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/ata/libata-core.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index 667acd283364..d6fcf0a1b7d8 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1478,7 +1478,16 @@ int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
}
tf.protocol = ATA_PROT_PIO;
- tf.flags |= ATA_TFLAG_POLLING; /* for polling presence detection */
+
+ /* Some devices choke if TF registers contain garbage. Make
+ * sure those are properly initialized.
+ */
+ tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
+
+ /* Device presence detection is unreliable on some
+ * controllers. Always poll IDENTIFY if available.
+ */
+ tf.flags |= ATA_TFLAG_POLLING;
err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
id, sizeof(id[0]) * ATA_ID_WORDS);