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, 9 insertions, 2 deletions

diff --git a/drivers/ide/ide-lib.c b/drivers/ide/ide-lib.c
index 4557fc5a3ea3..3be3c69383f2 100644
--- a/drivers/ide/ide-lib.c
+++ b/drivers/ide/ide-lib.c
@@ -88,8 +88,15 @@ u8 ide_rate_filter(ide_drive_t *drive, u8 speed)
 	if (hwif->udma_filter)
 		mask = hwif->udma_filter(drive);
 
-	if ((mask & 0x78) && (eighty_ninty_three(drive) == 0))
-		mask &= 0x07;
+	/*
+	 * TODO: speed > XFER_UDMA_2 extra check is needed to avoid false
+	 * cable warning from eighty_ninty_three(), moving ide_rate_filter()
+	 * calls from ->speedproc to core code will make this hack go away
+	 */
+	if (speed > XFER_UDMA_2) {
+		if ((mask & 0x78) && (eighty_ninty_three(drive) == 0))
+			mask &= 0x07;
+	}
 
 	if (mask)
 		mode = fls(mask) - 1 + XFER_UDMA_0;