ide: cable detection fixes (take 2)

Tejun's recent eighty_ninty_three() fix has inspired me to do more thorough
review of the cable detection code...

* print user-friendly warning about limiting the maximum transfer speed
  to UDMA33 (and the reason behind it) when 80-wire cable is not detected,
  also while at it cleanup eighty_ninty_three() a bit

* use eighty_ninty_three() in ide_ata66_check(), this actually fixes 3 bugs:
  - bit 14 (word 93 validity check) == 1 && bit 13 (80-wire cable test) == 1
    were used as 80-wire cable present test for CONFIG_IDEDMA_IVB=n case
    (please see FIXME comment in eighty_ninty_three() for more details)
  - CONFIG_IDEDMA_IVB=y/n cases were interchanged
  - check for SATA devices was missing

* remove private cable warnings from pdc_202xx{old,new} drivers now that core
  code provides this functionality (plus, in pdc202xx_new case the test could
  give false warnings for ATAPI devices because pdc202xx_new driver doesn't
  even support ATAPI DMA)

Cc: Tejun Heo <htejun@gmail.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 29 insertions, 24 deletions

diff --git a/drivers/ide/ide-iops.c b/drivers/ide/ide-iops.c
index ed6128f6cd98..f0be5f665a0e 100644
--- a/drivers/ide/ide-iops.c
+++ b/drivers/ide/ide-iops.c
@@ -571,25 +571,40 @@ EXPORT_SYMBOL(ide_wait_stat);
  */
 u8 eighty_ninty_three (ide_drive_t *drive)
 {
-        if(HWIF(drive)->udma_four == 0)
-                return 0;
+        ide_hwif_t *hwif = drive->hwif;
+        struct hd_driveid *id = drive->id;
+
+        if (hwif->udma_four == 0)
+                goto no_80w;
 
         /* Check for SATA but only if we are ATA5 or higher */
-        if (drive->id->hw_config == 0 && (drive->id->major_rev_num & 0x7FE0))
+        if (id->hw_config == 0 && (id->major_rev_num & 0x7FE0))
                 return 1;
-        if (!(drive->id->hw_config & 0x6000))
-                return 0;
-#ifndef CONFIG_IDEDMA_IVB
-        if(!(drive->id->hw_config & 0x4000))
-                return 0;
-#endif /* CONFIG_IDEDMA_IVB */
+
         /*
          * FIXME:
          * - change master/slave IDENTIFY order
          * - force bit13 (80c cable present) check
          *   (unless the slave device is pre-ATA3)
          */
-        return 1;
+#ifndef CONFIG_IDEDMA_IVB
+        if (id->hw_config & 0x4000)
+#else
+        if (id->hw_config & 0x6000)
+#endif
+                return 1;
+
+no_80w:
+        if (drive->udma33_warned == 1)
+                return 0;
+
+        printk(KERN_WARNING "%s: %s side 80-wire cable detection failed, "
+                            "limiting max speed to UDMA33\n",
+                            drive->name, hwif->udma_four ? "drive" : "host");
+
+        drive->udma33_warned = 1;
+
+        return 0;
 }
 
 int ide_ata66_check (ide_drive_t *drive, ide_task_t *args)
@@ -597,23 +612,13 @@ int ide_ata66_check (ide_drive_t *drive, ide_task_t *args)
         if ((args->tfRegister[IDE_COMMAND_OFFSET] == WIN_SETFEATURES) &&
             (args->tfRegister[IDE_SECTOR_OFFSET] > XFER_UDMA_2) &&
             (args->tfRegister[IDE_FEATURE_OFFSET] == SETFEATURES_XFER)) {
-#ifndef CONFIG_IDEDMA_IVB
-                if ((drive->id->hw_config & 0x6000) == 0) {
-#else /* !CONFIG_IDEDMA_IVB */
-                if (((drive->id->hw_config & 0x2000) == 0) ||
-                    ((drive->id->hw_config & 0x4000) == 0)) {
-#endif /* CONFIG_IDEDMA_IVB */
-                        printk("%s: Speed warnings UDMA 3/4/5 is not "
-                                "functional.\n", drive->name);
-                        return 1;
-                }
-                if (!HWIF(drive)->udma_four) {
-                        printk("%s: Speed warnings UDMA 3/4/5 is not "
-                                "functional.\n",
-                                HWIF(drive)->name);
+                if (eighty_ninty_three(drive) == 0) {
+                        printk(KERN_WARNING "%s: UDMA speeds >UDMA33 cannot "
+                                            "be set\n", drive->name);
                         return 1;
                 }
         }
+
         return 0;
 }