1 files changed, 33 insertions, 43 deletions

diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index f46eb6f6dc9f..a109ccbda9ca 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -4675,24 +4675,9 @@ int ata_check_atapi_dma(struct ata_queued_cmd *qc)
  */
 static int atapi_qc_may_overflow(struct ata_queued_cmd *qc)
 {
-        if (qc->tf.protocol != ATAPI_PROT_PIO &&
-            qc->tf.protocol != ATAPI_PROT_DMA)
-                return 0;
-
-        if (qc->tf.flags & ATA_TFLAG_WRITE)
-                return 0;
-
-        switch (qc->cdb[0]) {
-        case READ_10:
-        case READ_12:
-        case WRITE_10:
-        case WRITE_12:
-        case GPCMD_READ_CD:
-        case GPCMD_READ_CD_MSF:
-                return 0;
-        }
-
-        return 1;
+        return ata_is_atapi(qc->tf.protocol) && ata_is_data(qc->tf.protocol) &&
+                atapi_cmd_type(qc->cdb[0]) == ATAPI_MISC &&
+                !(qc->tf.flags & ATA_TFLAG_WRITE);
 }
 
 /**
@@ -5146,13 +5131,14 @@ static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
  */
 static int __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
 {
-        int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
+        int rw = (qc->tf.flags & ATA_TFLAG_WRITE) ? WRITE : READ;
         struct ata_port *ap = qc->ap;
-        struct ata_eh_info *ehi = &qc->dev->link->eh_info;
+        struct ata_device *dev = qc->dev;
+        struct ata_eh_info *ehi = &dev->link->eh_info;
         struct scatterlist *sg;
         struct page *page;
         unsigned char *buf;
-        unsigned int offset, count;
+        unsigned int offset, count, consumed;
 
 next_sg:
         sg = qc->cursg;
@@ -5165,26 +5151,27 @@ next_sg:
                  *    - for write case, padding zero data to the device
                  */
                 u16 pad_buf[1] = { 0 };
-                unsigned int i;
 
-                if (bytes > qc->curbytes - qc->nbytes + ATAPI_MAX_DRAIN) {
+                if (qc->curbytes + bytes > qc->nbytes + ATAPI_MAX_DRAIN) {
                         ata_ehi_push_desc(ehi, "too much trailing data "
                                           "buf=%u cur=%u bytes=%u",
                                           qc->nbytes, qc->curbytes, bytes);
                         return -1;
                 }
 
-                 /* overflow is exptected for misc ATAPI commands */
-                if (bytes && !atapi_qc_may_overflow(qc))
-                        ata_dev_printk(qc->dev, KERN_WARNING, "ATAPI %u bytes "
-                                       "trailing data (cdb=%02x nbytes=%u)\n",
-                                       bytes, qc->cdb[0], qc->nbytes);
+                /* allow overflow only for misc ATAPI commands */
+                if (!atapi_qc_may_overflow(qc)) {
+                        ata_ehi_push_desc(ehi, "unexpected trailing data "
+                                          "%u bytes", bytes);
+                        return -1;
+                }
 
-                for (i = 0; i < (bytes + 1) / 2; i++)
-                        ap->ops->data_xfer(qc->dev, (unsigned char *)pad_buf, 2, do_write);
+                consumed = 0;
+                while (consumed < bytes)
+                        consumed += ap->ops->data_xfer(dev,
+                                        (unsigned char *)pad_buf, 2, rw);
 
                 qc->curbytes += bytes;
-
                 return 0;
         }
 
@@ -5211,18 +5198,16 @@ next_sg:
                 buf = kmap_atomic(page, KM_IRQ0);
 
                 /* do the actual data transfer */
-                ap->ops->data_xfer(qc->dev,  buf + offset, count, do_write);
+                consumed = ap->ops->data_xfer(dev,  buf + offset, count, rw);
 
                 kunmap_atomic(buf, KM_IRQ0);
                 local_irq_restore(flags);
         } else {
                 buf = page_address(page);
-                ap->ops->data_xfer(qc->dev,  buf + offset, count, do_write);
+                consumed = ap->ops->data_xfer(dev,  buf + offset, count, rw);
         }
 
-        bytes -= count;
-        if ((count & 1) && bytes)
-                bytes--;
+        bytes -= min(bytes, consumed);
         qc->curbytes += count;
         qc->cursg_ofs += count;
 
@@ -5231,9 +5216,11 @@ next_sg:
                 qc->cursg_ofs = 0;
         }
 
+        /* consumed can be larger than count only for the last transfer */
+        WARN_ON(qc->cursg && count != consumed);
+
         if (bytes)
                 goto next_sg;
-
         return 0;
 }
 
@@ -5251,6 +5238,7 @@ static void atapi_pio_bytes(struct ata_queued_cmd *qc)
 {
         struct ata_port *ap = qc->ap;
         struct ata_device *dev = qc->dev;
+        struct ata_eh_info *ehi = &dev->link->eh_info;
         unsigned int ireason, bc_lo, bc_hi, bytes;
         int i_write, do_write = (qc->tf.flags & ATA_TFLAG_WRITE) ? 1 : 0;
 
@@ -5268,26 +5256,28 @@ static void atapi_pio_bytes(struct ata_queued_cmd *qc)
 
         /* shall be cleared to zero, indicating xfer of data */
         if (unlikely(ireason & (1 << 0)))
-                goto err_out;
+                goto atapi_check;
 
         /* make sure transfer direction matches expected */
         i_write = ((ireason & (1 << 1)) == 0) ? 1 : 0;
         if (unlikely(do_write != i_write))
-                goto err_out;
+                goto atapi_check;
 
         if (unlikely(!bytes))
-                goto err_out;
+                goto atapi_check;
 
         VPRINTK("ata%u: xfering %d bytes\n", ap->print_id, bytes);
 
-        if (__atapi_pio_bytes(qc, bytes))
+        if (unlikely(__atapi_pio_bytes(qc, bytes)))
                 goto err_out;
         ata_altstatus(ap); /* flush */
 
         return;
 
-err_out:
-        ata_dev_printk(dev, KERN_INFO, "ATAPI check failed\n");
+ atapi_check:
+        ata_ehi_push_desc(ehi, "ATAPI check failed (ireason=0x%x bytes=%u)",
+                          ireason, bytes);
+ err_out:
         qc->err_mask |= AC_ERR_HSM;
         ap->hsm_task_state = HSM_ST_ERR;
 }