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>

diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c
index 07f41be38fbe556ffff9bd5efcacf8ed4538034e..2893563d05372e87c375da34ac6872581d53d1e1 100644 (file)
--- 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;
 }

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 8dad4a307bb8c4b086e8f6f62211d91d8c05a53a..c3ef58014b33cbbc0d68ab487376e59c24158d63 100644 (file)
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -424,6 +424,7 @@ enum {
        ATA_HORKAGE_NOLPM       = (1 << 20),    /* don't use LPM */
        ATA_HORKAGE_WD_BROKEN_LPM = (1 << 21),  /* some WDs have broken LPM */
        ATA_HORKAGE_ZERO_AFTER_TRIM = (1 << 22),/* guarantees zero after trim */
+       ATA_HORKAGE_NO_NCQ_LOG  = (1 << 23),    /* don't use NCQ for log read */
 
         /* DMA mask for user DMA control: User visible values; DO NOT
            renumber */