ide: DMA reporting and validity checking fixes (take 3)

* ide_xfer_verbose() fixups:
  - beautify returned mode names
  - fix PIO5 reporting
  - make it return 'const char *'

* Change printk() level from KERN_DEBUG to KERN_INFO in ide_find_dma_mode().

* Add ide_id_dma_bug() helper based on ide_dma_verbose() to check for invalid
  DMA info in identify block.

* Use ide_id_dma_bug() in ide_tune_dma() and ide_driveid_update().

  As a result DMA won't be tuned or will be disabled after tuning if device
  reports inconsistent info about enabled DMA mode (ide_dma_verbose() does the
  same checks while the IDE device is probed by ide-{cd,disk} device driver).

* Remove no longer needed ide_dma_verbose().

This patch should fix the following problem with out-of-sync IDE messages
reported by Nick Warne:

       hdd: ATAPI 48X DVD-ROM DVD-R-RAM CD-R/RW drive, 2048kB Cache<7>hdd:
       skipping word 93 validity check
        , UDMA(66)

and later debugged by Mark Lord to be caused by:

        ide_dma_verbose()
                printk( ... "2048kB Cache");
        eighty_ninty_three()
                printk(KERN_DEBUG "%s: skipping word 93 validity check\n");
        ide_dma_verbose()
                printk(", UDMA(66)"

Please note that as a result ide-{cd,disk} device drivers won't report the
DMA speed used but this is intended since now DMA mode being used is always
reported by IDE core code.

v2:
* fixes suggested by Randy:
  - use KERN_CONT for printk()-s in ide-{cd,disk}.c
  - don't remove argument name from ide_xfer_verbose() declaration

v3:
* Remove incorrect check for (id->field_valid & 1) from ide_id_dma_bug()
  (spotted by Sergei).

* "XFER SLOW" -> "PIO SLOW" in ide_xfer_verbose() (suggested by Sergei).

* Fix ide_find_dma_mode() to report the correct mode ('mode' after being
  limited by 'req_mode').

Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Nick Warne <nick@ukfsn.org>
Cc: Mark Lord <lkml@rtr.ca>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

5 files changed, 50 insertions, 82 deletions

diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 57a5f63d6ae..db9abd83d95 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -3049,12 +3049,7 @@ int ide_cdrom_probe_capabilities (ide_drive_t *drive)
         else    
                 printk(" drive");
 
-        printk(", %dkB Cache", be16_to_cpu(cap.buffer_size));
-
-        if (drive->using_dma)
-                ide_dma_verbose(drive);
-
-        printk("\n");
+        printk(KERN_CONT ", %dkB Cache\n", be16_to_cpu(cap.buffer_size));
 
         return nslots;
 }
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index 00123d99527..b77c849cdd2 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -961,11 +961,8 @@ static void idedisk_setup (ide_drive_t *drive)
         if (id->buf_size)
                 printk (" w/%dKiB Cache", id->buf_size/2);
 
-        printk(", CHS=%d/%d/%d", 
-               drive->bios_cyl, drive->bios_head, drive->bios_sect);
-        if (drive->using_dma)
-                ide_dma_verbose(drive);
-        printk("\n");
+        printk(KERN_CONT ", CHS=%d/%d/%d\n",
+                         drive->bios_cyl, drive->bios_head, drive->bios_sect);
 
         /* write cache enabled? */
         if ((id->csfo & 1) || (id->cfs_enable_1 & (1 << 5)))
diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index 0d795a1678c..6879aaae544 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -753,10 +753,12 @@ u8 ide_find_dma_mode(ide_drive_t *drive, u8 req_mode)
                         mode = XFER_MW_DMA_1;
         }
 
-        printk(KERN_DEBUG "%s: %s mode selected\n", drive->name,
+        mode = min(mode, req_mode);
+
+        printk(KERN_INFO "%s: %s mode selected\n", drive->name,
                           mode ? ide_xfer_verbose(mode) : "no DMA");
 
-        return min(mode, req_mode);
+        return mode;
 }
 
 EXPORT_SYMBOL_GPL(ide_find_dma_mode);
@@ -772,6 +774,9 @@ static int ide_tune_dma(ide_drive_t *drive)
         if (__ide_dma_bad_drive(drive))
                 return 0;
 
+        if (ide_id_dma_bug(drive))
+                return 0;
+
         if (drive->hwif->host_flags & IDE_HFLAG_TRUST_BIOS_FOR_DMA)
                 return config_drive_for_dma(drive);
 
@@ -806,58 +811,23 @@ static int ide_dma_check(ide_drive_t *drive)
         return vdma ? 0 : -1;
 }
 
-void ide_dma_verbose(ide_drive_t *drive)
+int ide_id_dma_bug(ide_drive_t *drive)
 {
-        struct hd_driveid *id   = drive->id;
-        ide_hwif_t *hwif        = HWIF(drive);
+        struct hd_driveid *id = drive->id;
 
         if (id->field_valid & 4) {
                 if ((id->dma_ultra >> 8) && (id->dma_mword >> 8))
-                        goto bug_dma_off;
-                if (id->dma_ultra & ((id->dma_ultra >> 8) & hwif->ultra_mask)) {
-                        if (((id->dma_ultra >> 11) & 0x1F) &&
-                            eighty_ninty_three(drive)) {
-                                if ((id->dma_ultra >> 15) & 1) {
-                                        printk(", UDMA(mode 7)");
-                                } else if ((id->dma_ultra >> 14) & 1) {
-                                        printk(", UDMA(133)");
-                                } else if ((id->dma_ultra >> 13) & 1) {
-                                        printk(", UDMA(100)");
-                                } else if ((id->dma_ultra >> 12) & 1) {
-                                        printk(", UDMA(66)");
-                                } else if ((id->dma_ultra >> 11) & 1) {
-                                        printk(", UDMA(44)");
-                                } else
-                                        goto mode_two;
-                        } else {
-                mode_two:
-                                if ((id->dma_ultra >> 10) & 1) {
-                                        printk(", UDMA(33)");
-                                } else if ((id->dma_ultra >> 9) & 1) {
-                                        printk(", UDMA(25)");
-                                } else if ((id->dma_ultra >> 8) & 1) {
-                                        printk(", UDMA(16)");
-                                }
-                        }
-                } else {
-                        printk(", (U)DMA");     /* Can be BIOS-enabled! */
-                }
+                        goto err_out;
         } else if (id->field_valid & 2) {
                 if ((id->dma_mword >> 8) && (id->dma_1word >> 8))
-                        goto bug_dma_off;
-                printk(", DMA");
-        } else if (id->field_valid & 1) {
-                goto bug_dma_off;
+                        goto err_out;
         }
-        return;
-bug_dma_off:
-        printk(", BUG DMA OFF");
-        hwif->dma_off_quietly(drive);
-        return;
+        return 0;
+err_out:
+        printk(KERN_ERR "%s: bad DMA info in identify block\n", drive->name);
+        return 1;
 }
 
-EXPORT_SYMBOL(ide_dma_verbose);
-
 int ide_set_dma(ide_drive_t *drive)
 {
         ide_hwif_t *hwif = drive->hwif;
diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c
index 5c3256180ae..cef405ddaf0 100644
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -748,6 +748,9 @@ int ide_driveid_update(ide_drive_t *drive)
                 drive->id->dma_1word = id->dma_1word;
                 /* anything more ? */
                 kfree(id);
+
+                if (drive->using_dma && ide_id_dma_bug(drive))
+                        ide_dma_off(drive);
         }
 
         return 1;
diff --git a/drivers/ide/ide-lib.c b/drivers/ide/ide-lib.c
index 1609b8604f5..062d3bcb247 100644
--- a/drivers/ide/ide-lib.c
+++ b/drivers/ide/ide-lib.c
@@ -29,41 +29,44 @@
  *      Add common non I/O op stuff here. Make sure it has proper
  *      kernel-doc function headers or your patch will be rejected
  */
- 
+
+static const char *udma_str[] =
+         { "UDMA/16", "UDMA/25",  "UDMA/33",  "UDMA/44",
+           "UDMA/66", "UDMA/100", "UDMA/133", "UDMA7" };
+static const char *mwdma_str[] =
+        { "MWDMA0", "MWDMA1", "MWDMA2" };
+static const char *swdma_str[] =
+        { "SWDMA0", "SWDMA1", "SWDMA2" };
+static const char *pio_str[] =
+        { "PIO0", "PIO1", "PIO2", "PIO3", "PIO4", "PIO5" };
 
 /**
  *      ide_xfer_verbose        -       return IDE mode names
- *      @xfer_rate: rate to name
+ *      @mode: transfer mode
  *
  *      Returns a constant string giving the name of the mode
  *      requested.
  */
 
-char *ide_xfer_verbose (u8 xfer_rate)
+const char *ide_xfer_verbose(u8 mode)
 {
-        switch(xfer_rate) {
-                case XFER_UDMA_7:       return("UDMA 7");
-                case XFER_UDMA_6:       return("UDMA 6");
-                case XFER_UDMA_5:       return("UDMA 5");
-                case XFER_UDMA_4:       return("UDMA 4");
-                case XFER_UDMA_3:       return("UDMA 3");
-                case XFER_UDMA_2:       return("UDMA 2");
-                case XFER_UDMA_1:       return("UDMA 1");
-                case XFER_UDMA_0:       return("UDMA 0");
-                case XFER_MW_DMA_2:     return("MW DMA 2");
-                case XFER_MW_DMA_1:     return("MW DMA 1");
-                case XFER_MW_DMA_0:     return("MW DMA 0");
-                case XFER_SW_DMA_2:     return("SW DMA 2");
-                case XFER_SW_DMA_1:     return("SW DMA 1");
-                case XFER_SW_DMA_0:     return("SW DMA 0");
-                case XFER_PIO_4:        return("PIO 4");
-                case XFER_PIO_3:        return("PIO 3");
-                case XFER_PIO_2:        return("PIO 2");
-                case XFER_PIO_1:        return("PIO 1");
-                case XFER_PIO_0:        return("PIO 0");
-                case XFER_PIO_SLOW:     return("PIO SLOW");
-                default:                return("XFER ERROR");
-        }
+        const char *s;
+        u8 i = mode & 0xf;
+
+        if (mode >= XFER_UDMA_0 && mode <= XFER_UDMA_7)
+                s = udma_str[i];
+        else if (mode >= XFER_MW_DMA_0 && mode <= XFER_MW_DMA_2)
+                s = mwdma_str[i];
+        else if (mode >= XFER_SW_DMA_0 && mode <= XFER_SW_DMA_2)
+                s = swdma_str[i];
+        else if (mode >= XFER_PIO_0 && mode <= XFER_PIO_5)
+                s = pio_str[i & 0x7];
+        else if (mode == XFER_PIO_SLOW)
+                s = "PIO SLOW";
+        else
+                s = "XFER ERROR";
+
+        return s;
 }
 
 EXPORT_SYMBOL(ide_xfer_verbose);