libata: Fall back to unqueued READ LOG EXT if the DMA variant fails

Some devices advertise support for the READ/WRITE LOG DMA EXT commands
but fail when we try to issue them. This can lead to queued TRIM being
unintentionally disabled since the relevant feature flag is located in a
general purpose log page.

Fall back to unqueued READ LOG EXT if the DMA variant fails while
reading a log page.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 11 insertions, 1 deletions

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 07f41be38fbe..2893563d0537 100644
--- a/drivers/ata/libata-eh.c
+++ b/drivers/ata/libata-eh.c
@@ -1507,13 +1507,17 @@ unsigned int ata_read_log_page(struct ata_device *dev, u8 log,
 {
         struct ata_taskfile tf;
         unsigned int err_mask;
+        bool dma = false;
 
         DPRINTK("read log page - log 0x%x, page 0x%x\n", log, page);
 
+retry:
         ata_tf_init(dev, &tf);
-        if (dev->dma_mode && ata_id_has_read_log_dma_ext(dev->id)) {
+        if (dev->dma_mode && ata_id_has_read_log_dma_ext(dev->id) &&
+            !(dev->horkage & ATA_HORKAGE_NO_NCQ_LOG)) {
                 tf.command = ATA_CMD_READ_LOG_DMA_EXT;
                 tf.protocol = ATA_PROT_DMA;
+                dma = true;
         } else {
                 tf.command = ATA_CMD_READ_LOG_EXT;
                 tf.protocol = ATA_PROT_PIO;
@@ -1527,6 +1531,12 @@ unsigned int ata_read_log_page(struct ata_device *dev, u8 log,
         err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
                                      buf, sectors * ATA_SECT_SIZE, 0);
 
+        if (err_mask && dma) {
+                dev->horkage |= ATA_HORKAGE_NO_NCQ_LOG;
+                ata_dev_warn(dev, "READ LOG DMA EXT failed, trying unqueued\n");
+                goto retry;
+        }
+
         DPRINTK("EXIT, err_mask=%x\n", err_mask);
         return err_mask;
 }