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-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 25d8d3f778a1..2cf8251728d2 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1410,7 +1410,16 @@ 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);
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