ide-{floppy,tape}: fix padding for PIO transfers
Bartlomiej Zolnierkiewicz [Tue, 31 Mar 2009 18:15:26 +0000 (20:15 +0200)]
* Return number of bytes left to transfer from idetape_{in,out}put_buffers()
  and number of bytes done from ide_tape_io_buffers().

* Fix padding for PIO transfers in ide_pc_intr() so read/write buffers are
  always completely processed and then the transfer is padded if necessary.

* Remove invalid error messages.

* Remove now superfluous padding from ide{_io_buffers,tape_input_buffers}().

While at it:

* Set pc->bh to NULL in idetape_input_buffers() after all bh-s are done.

* Cache !!(pc->flags & PC_FLAG_WRITING) in local variable in ide_pc_intr().

Cc: Borislav Petkov <petkovbb@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

drivers/ide/ide-atapi.c
drivers/ide/ide-tape.c

index 3f3fc7c..40f413b 100644 (file)
@@ -110,13 +110,6 @@ int ide_io_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
                }
        }
 
-       if (bcount) {
-               printk(KERN_ERR "%s: %d leftover bytes, %s\n", drive->name,
-                       bcount, write ? "padding with zeros"
-                                     : "discarding data");
-               ide_pad_transfer(drive, write, bcount);
-       }
-
        return done;
 }
 EXPORT_SYMBOL_GPL(ide_io_buffers);
@@ -330,9 +323,10 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
        struct request *rq = hwif->rq;
        const struct ide_tp_ops *tp_ops = hwif->tp_ops;
        xfer_func_t *xferfunc;
-       unsigned int timeout, temp;
+       unsigned int timeout, done;
        u16 bcount;
        u8 stat, ireason, dsc = 0;
+       u8 write = !!(pc->flags & PC_FLAG_WRITING);
 
        debug_log("Enter %s - interrupt handler\n", __func__);
 
@@ -441,8 +435,7 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
                return ide_do_reset(drive);
        }
 
-       if (((ireason & ATAPI_IO) == ATAPI_IO) ==
-               !!(pc->flags & PC_FLAG_WRITING)) {
+       if (((ireason & ATAPI_IO) == ATAPI_IO) == write) {
                /* Hopefully, we will never get here */
                printk(KERN_ERR "%s: We wanted to %s, but the device wants us "
                                "to %s!\n", drive->name,
@@ -451,45 +444,33 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
                return ide_do_reset(drive);
        }
 
-       if (!(pc->flags & PC_FLAG_WRITING)) {
-               /* Reading - Check that we have enough space */
-               temp = pc->xferred + bcount;
-               if (temp > pc->req_xfer) {
-                       if (temp > pc->buf_size) {
-                               printk(KERN_ERR "%s: The device wants to send "
-                                               "us more data than expected - "
-                                               "discarding data\n",
-                                               drive->name);
-
-                               ide_pad_transfer(drive, 0, bcount);
-                               goto next_irq;
-                       }
-                       debug_log("The device wants to send us more data than "
-                                 "expected - allowing transfer\n");
-               }
-               xferfunc = tp_ops->input_data;
-       } else
-               xferfunc = tp_ops->output_data;
+       xferfunc = write ? tp_ops->output_data : tp_ops->input_data;
 
        if ((drive->media == ide_floppy && !pc->buf) ||
            (drive->media == ide_tape && pc->bh)) {
-               int done = drive->pc_io_buffers(drive, pc, bcount,
-                                 !!(pc->flags & PC_FLAG_WRITING));
+               done = drive->pc_io_buffers(drive, pc, bcount, write);
 
                /* FIXME: don't do partial completions */
                if (drive->media == ide_floppy)
                        ide_complete_rq(drive, 0,
                                        done ? done : ide_rq_bytes(rq));
-       } else
-               xferfunc(drive, NULL, pc->cur_pos, bcount);
+       } else {
+               done = min_t(unsigned int, bcount, pc->req_xfer - pc->xferred);
+               xferfunc(drive, NULL, pc->cur_pos, done);
+       }
 
        /* Update the current position */
-       pc->xferred += bcount;
-       pc->cur_pos += bcount;
+       pc->xferred += done;
+       pc->cur_pos += 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 on that intr.\n",
-                 rq->cmd[0], bcount);
-next_irq:
        /* And set the interrupt handler again */
        ide_set_handler(drive, ide_pc_intr, timeout);
        return ide_started;
index cafc67d..cb942a9 100644 (file)
@@ -297,19 +297,15 @@ static struct ide_tape_obj *ide_tape_chrdev_get(unsigned int i)
        return tape;
 }
 
-static void idetape_input_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
+static int idetape_input_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
                                  unsigned int bcount)
 {
        struct idetape_bh *bh = pc->bh;
        int count;
 
        while (bcount) {
-               if (bh == NULL) {
-                       printk(KERN_ERR "ide-tape: bh == NULL in "
-                               "idetape_input_buffers\n");
-                       ide_pad_transfer(drive, 0, bcount);
-                       return;
-               }
+               if (bh == NULL)
+                       break;
                count = min(
                        (unsigned int)(bh->b_size - atomic_read(&bh->b_count)),
                        bcount);
@@ -323,21 +319,21 @@ static void idetape_input_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
                                atomic_set(&bh->b_count, 0);
                }
        }
+
        pc->bh = bh;
+
+       return bcount;
 }
 
-static void idetape_output_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
+static int idetape_output_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
                                   unsigned int bcount)
 {
        struct idetape_bh *bh = pc->bh;
        int count;
 
        while (bcount) {
-               if (bh == NULL) {
-                       printk(KERN_ERR "ide-tape: bh == NULL in %s\n",
-                                       __func__);
-                       return;
-               }
+               if (bh == NULL)
+                       break;
                count = min((unsigned int)pc->b_count, (unsigned int)bcount);
                drive->hwif->tp_ops->output_data(drive, NULL, pc->b_data, count);
                bcount -= count;
@@ -352,6 +348,8 @@ static void idetape_output_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
                        }
                }
        }
+
+       return bcount;
 }
 
 static void idetape_update_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc)
@@ -563,12 +561,14 @@ static void ide_tape_handle_dsc(ide_drive_t *drive)
 static int ide_tape_io_buffers(ide_drive_t *drive, struct ide_atapi_pc *pc,
                                unsigned int bcount, int write)
 {
+       unsigned int bleft;
+
        if (write)
-               idetape_output_buffers(drive, pc, bcount);
+               bleft = idetape_output_buffers(drive, pc, bcount);
        else
-               idetape_input_buffers(drive, pc, bcount);
+               bleft = idetape_input_buffers(drive, pc, bcount);
 
-       return bcount;
+       return bcount - bleft;
 }
 
 /*