1 files changed, 17 insertions, 4 deletions

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 0eae9b453556..0b299b0f8172 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -1013,9 +1013,12 @@ next_sg:
                 qc->cursg_ofs = 0;
         }
 
-        /* consumed can be larger than count only for the last transfer */
-        WARN_ON_ONCE(qc->cursg && count != consumed);
-
+        /*
+         * There used to be a  WARN_ON_ONCE(qc->cursg && count != consumed);
+         * Unfortunately __atapi_pio_bytes doesn't know enough to do the WARN
+         * check correctly as it doesn't know if it is the last request being
+         * made. Somebody should implement a proper sanity check.
+         */
         if (bytes)
                 goto next_sg;
         return 0;
@@ -1319,7 +1322,7 @@ fsm_start:
                                          * condition.  Mark hint.
                                          */
                                         ata_ehi_push_desc(ehi, "ST-ATA: "
-                                                "DRQ=1 with device error, "
+                                                "DRQ=0 without device error, "
                                                 "dev_stat 0x%X", status);
                                         qc->err_mask |= AC_ERR_HSM |
                                                         AC_ERR_NODEV_HINT;
@@ -1355,6 +1358,16 @@ fsm_start:
                                         qc->err_mask |= AC_ERR_HSM;
                                 }
 
+                                /* There are oddball controllers with
+                                 * status register stuck at 0x7f and
+                                 * lbal/m/h at zero which makes it
+                                 * pass all other presence detection
+                                 * mechanisms we have.  Set NODEV_HINT
+                                 * for it.  Kernel bz#7241.
+                                 */
+                                if (status == 0x7f)
+                                        qc->err_mask |= AC_ERR_NODEV_HINT;
+
                                 /* ata_pio_sectors() might change the
                                  * state to HSM_ST_LAST. so, the state
                                  * is changed after ata_pio_sectors().