1 files changed, 38 insertions, 11 deletions

diff --git a/drivers/ata/libata-sff.c b/drivers/ata/libata-sff.c
index 0eae9b453556..714cb046b594 100644
--- a/drivers/ata/libata-sff.c
+++ b/drivers/ata/libata-sff.c
@@ -773,18 +773,32 @@ unsigned int ata_sff_data_xfer32(struct ata_device *dev, unsigned char *buf,
         else
                 iowrite32_rep(data_addr, buf, words);
 
+        /* Transfer trailing bytes, if any */
         if (unlikely(slop)) {
-                __le32 pad;
+                unsigned char pad[4];
+
+                /* Point buf to the tail of buffer */
+                buf += buflen - slop;
+
+                /*
+                 * Use io*_rep() accessors here as well to avoid pointlessly
+                 * swapping bytes to and fro on the big endian machines...
+                 */
                 if (rw == READ) {
-                        pad = cpu_to_le32(ioread32(ap->ioaddr.data_addr));
-                        memcpy(buf + buflen - slop, &pad, slop);
+                        if (slop < 3)
+                                ioread16_rep(data_addr, pad, 1);
+                        else
+                                ioread32_rep(data_addr, pad, 1);
+                        memcpy(buf, pad, slop);
                 } else {
-                        memcpy(&pad, buf + buflen - slop, slop);
-                        iowrite32(le32_to_cpu(pad), ap->ioaddr.data_addr);
+                        memcpy(pad, buf, slop);
+                        if (slop < 3)
+                                iowrite16_rep(data_addr, pad, 1);
+                        else
+                                iowrite32_rep(data_addr, pad, 1);
                 }
-                words++;
         }
-        return words << 2;
+        return (buflen + 1) & ~1;
 }
 EXPORT_SYMBOL_GPL(ata_sff_data_xfer32);
 
@@ -1013,9 +1027,12 @@ 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 +1336,7 @@ 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 +1372,16 @@ 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().