scc_pata: bugfix for checking DMA IRQ status

On Tuesday 27 February 2007, Akira Iguchi wrote:
>
> But since I sent the first patch, I found a bug for checking DMA IRQ status.
> (http://www.spinics.net/lists/linux-ide/msg06903.html)
> Then I sent the fixed patch for libata only. So my drivers/ide patch
> still has same bug and I want to fix it, too.
>
> The following patch fixes this bug. Please apply this patch.

From: Akira Iguchi <akira2.iguchi@toshiba.co.jp>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

diff --git a/drivers/ide/ppc/scc_pata.c b/drivers/ide/ppc/scc_pata.c
index de64b022478b9158edaf471dc31657ec2e56d022..f84bf791f72e901605594a79cb0f61491a8faac4 100644 (file)
--- a/drivers/ide/ppc/scc_pata.c
+++ b/drivers/ide/ppc/scc_pata.c
@@ -509,6 +509,32 @@ static int scc_ide_dma_end(ide_drive_t * drive)
        return __ide_dma_end(drive);
 }
 
+/* returns 1 if dma irq issued, 0 otherwise */
+static int scc_dma_test_irq(ide_drive_t *drive)
+{
+       ide_hwif_t *hwif        = HWIF(drive);
+       u8 dma_stat             = hwif->INB(hwif->dma_status);
+
+       /* return 1 if INTR asserted */
+       if ((dma_stat & 4) == 4)
+               return 1;
+
+       /* Workaround for PTERADD: emulate DMA_INTR when
+        * - IDE_STATUS[ERR] = 1
+        * - INT_STATUS[INTRQ] = 1
+        * - DMA_STATUS[IORACTA] = 1
+        */
+       if (in_be32((void __iomem *)IDE_ALTSTATUS_REG) & ERR_STAT &&
+           in_be32((void __iomem *)(hwif->dma_base + 0x014)) & INTSTS_INTRQ &&
+               dma_stat & 1)
+               return 1;
+
+       if (!drive->waiting_for_dma)
+               printk(KERN_WARNING "%s: (%s) called while not waiting\n",
+                       drive->name, __FUNCTION__);
+       return 0;
+}
+
 /**
  *     setup_mmio_scc  -       map CTRL/BMID region
  *     @dev: PCI device we are configuring
@@ -712,6 +738,7 @@ static void __devinit init_hwif_scc(ide_hwif_t *hwif)
        hwif->speedproc = scc_tune_chipset;
        hwif->tuneproc = scc_tuneproc;
        hwif->ide_dma_check = scc_config_drive_for_dma;
+       hwif->ide_dma_test_irq = scc_dma_test_irq;
 
        hwif->drives[0].autotune = IDE_TUNE_AUTO;
        hwif->drives[1].autotune = IDE_TUNE_AUTO;