ide-atapi: switch to rq->resid_len

Now that we have rq->resid_len, use it to account partial completion
amount during the lifetime of an rq, decrementing it on each successful
transfer. As a result, get rid of now unused pc->xferred.

While at it, remove noisy debug call in ide_prep_sense.

Signed-off-by: Borislav Petkov <petkovbb@gmail.com>

3 files changed, 13 insertions, 20 deletions

diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index 7129495b3e40..1022e421abd8 100644
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -172,8 +172,6 @@ void ide_prep_sense(ide_drive_t *drive, struct request *rq)
         unsigned int cmd_len, sense_len;
         int err;
 
-        debug_log("%s: enter\n", __func__);
-
         switch (drive->media) {
         case ide_floppy:
                 cmd_len = 255;
@@ -370,7 +368,7 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
                                                      ? "write" : "read");
                         pc->flags |= PC_FLAG_DMA_ERROR;
                 } else
-                        pc->xferred = blk_rq_bytes(rq);
+                        rq->resid_len = 0;
                 debug_log("%s: DMA finished\n", drive->name);
         }
 
@@ -379,7 +377,7 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
                 int uptodate, error;
 
                 debug_log("Packet command completed, %d bytes transferred\n",
-                          pc->xferred);
+                          blk_rq_bytes(rq));
 
                 pc->flags &= ~PC_FLAG_DMA_IN_PROGRESS;
 
@@ -467,15 +465,15 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
         ide_pio_bytes(drive, cmd, write, done);
 
         /* Update transferred byte count */
-        pc->xferred += done;
+        rq->resid_len -= done;
 
         bcount -= done;
 
         if (bcount)
                 ide_pad_transfer(drive, write, bcount);
 
-        debug_log("[cmd %x] transferred %d bytes, padded %d bytes\n",
-                  rq->cmd[0], done, bcount);
+        debug_log("[cmd %x] transferred %d bytes, padded %d bytes, resid: %u\n",
+                  rq->cmd[0], done, bcount, rq->resid_len);
 
         /* And set the interrupt handler again */
         ide_set_handler(drive, ide_pc_intr, timeout);
@@ -643,16 +641,15 @@ ide_startstop_t ide_issue_pc(ide_drive_t *drive, struct ide_cmd *cmd)
         } else {
                 pc = drive->pc;
 
-                /* We haven't transferred any data yet */
-                pc->xferred = 0;
-
                 valid_tf = IDE_VALID_DEVICE;
                 bytes = blk_rq_bytes(rq);
-
                 bcount = ((drive->media == ide_tape) ? bytes
                                                      : min_t(unsigned int,
                                                              bytes, 63 * 1024));
 
+                /* We haven't transferred any data yet */
+                rq->resid_len = bcount;
+
                 if (pc->flags & PC_FLAG_DMA_ERROR) {
                         pc->flags &= ~PC_FLAG_DMA_ERROR;
                         ide_dma_off(drive);
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index aaeef12f80ad..c93370997972 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -301,11 +301,9 @@ static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
         debug_log(DBG_ERR, "pc = %x, sense key = %x, asc = %x, ascq = %x\n",
                  pc->c[0], tape->sense_key, tape->asc, tape->ascq);
 
-        /* Correct pc->xferred by asking the tape.       */
+        /* correct remaining bytes to transfer */
         if (pc->flags & PC_FLAG_DMA_ERROR)
-                pc->xferred = blk_rq_bytes(rq) -
-                        tape->blk_size *
-                        get_unaligned_be32(&sense[3]);
+                rq->resid_len = tape->blk_size * get_unaligned_be32(&sense[3]);
 
         /*
          * If error was the result of a zero-length read or write command,
@@ -339,7 +337,7 @@ static void idetape_analyze_error(ide_drive_t *drive, u8 *sense)
                         pc->flags |= PC_FLAG_ABORT;
                 }
                 if (!(pc->flags & PC_FLAG_ABORT) &&
-                    pc->xferred)
+                    (blk_rq_bytes(rq) - rq->resid_len))
                         pc->retries = IDETAPE_MAX_PC_RETRIES + 1;
         }
 }
@@ -369,7 +367,8 @@ static int ide_tape_callback(ide_drive_t *drive, int dsc)
                         printk(KERN_ERR "ide-tape: Error in REQUEST SENSE "
                                         "itself - Aborting request!\n");
         } else if (pc->c[0] == READ_6 || pc->c[0] == WRITE_6) {
-                int blocks = pc->xferred / tape->blk_size;
+                unsigned int blocks =
+                        (blk_rq_bytes(rq) - rq->resid_len) / tape->blk_size;
 
                 tape->avg_size += blocks * tape->blk_size;
 
@@ -381,7 +380,6 @@ static int ide_tape_callback(ide_drive_t *drive, int dsc)
                 }
 
                 tape->first_frame += blocks;
-                rq->resid_len = blk_rq_bytes(rq) - blocks * tape->blk_size;
 
                 if (pc->error) {
                         uptodate = 0;
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 34c128f0a33c..745a393af278 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -357,8 +357,6 @@ struct ide_atapi_pc {
 
         /* bytes to transfer */
         int req_xfer;
-        /* bytes actually transferred */
-        int xferred;
 
         /* data buffer */
         u8 *buf;