[RFC] Get DMA to work for CD/DVD with pdc202xx_old

[Tobias Oed]

Hello,
I send something similar to linux-ide some weeks ago but got no reply.
This patch against 2.6.17-rc1-mm3 for pdc202xx_old.c allows me to
enable dma on my DVD and CD drives attached to my on board
pdc20265 ide controller. It works with udma modes only.
Tobias

--- pdc202xx_old.c.1    2006-04-18 13:12:47.000000000 +0200
+++ pdc202xx_old.c      2006-04-18 14:21:57.000000000 +0200
@@ -180,9 +180,11 @@
       u8                      AP, BP, CP, DP;
       u8                      TA = 0, TB = 0, TC = 0;

+       #if 0
       if ((drive->media != ide_disk) && (speed < XFER_SW_DMA_0))
               return -1;
-
+       #endif
+
       pci_read_config_dword(dev, drive_pci, &drive_conf);
       pci_read_config_byte(dev, (drive_pci), &AP);
       pci_read_config_byte(dev, (drive_pci)|0x01, &BP);
@@ -356,14 +358,12 @@

chipset_is_set:

-       if (drive->media == ide_disk) {
-               pci_read_config_byte(dev, (drive_pci), &AP);
-               if (id->capability & 4) /* IORDY_EN */
-                       pci_write_config_byte(dev, (drive_pci), 
AP|IORDY_EN);
-               pci_read_config_byte(dev, (drive_pci), &AP);
-               if (drive->media == ide_disk)   /* PREFETCH_EN */
-                       pci_write_config_byte(dev, (drive_pci), 
AP|PREFETCH_EN);
-       }
+       pci_read_config_byte(dev, (drive_pci), &AP);
+       if (id->capability & 4) /* IORDY_EN */
+               pci_write_config_byte(dev, (drive_pci), AP|IORDY_EN);
+       pci_read_config_byte(dev, (drive_pci), &AP);
+       if (drive->media == ide_disk)   /* PREFETCH_EN */
+               pci_write_config_byte(dev, (drive_pci), AP|PREFETCH_EN);

       speed = ide_dma_speed(drive, pdc202xx_ratemask(drive));

@@ -411,7 +411,7 @@
{
       if (drive->current_speed > XFER_UDMA_2)
               pdc_old_enable_66MHz_clock(drive->hwif);
-       if (drive->addressing == 1) {
+       if (drive->media != ide_disk || drive->addressing == 1) {
               struct request *rq      = HWGROUP(drive)->rq;
               ide_hwif_t *hwif        = HWIF(drive);
//             struct pci_dev *dev     = hwif->pci_dev;
@@ -433,7 +433,7 @@

static int pdc202xx_old_ide_dma_end(ide_drive_t *drive)
{
-       if (drive->addressing == 1) {
+       if (drive->media != ide_disk || drive->addressing == 1) {
               ide_hwif_t *hwif        = HWIF(drive);
//             unsigned long high_16   = pci_resource_start(hwif->pci_dev, 
4);
               unsigned long high_16   = hwif->dma_master;
@@ -635,6 +635,7 @@
       hwif->ultra_mask = 0x3f;
       hwif->mwdma_mask = 0x07;
       hwif->swdma_mask = 0x07;
+        hwif->atapi_dma = 1;

       hwif->ide_dma_check = &pdc202xx_config_drive_xfer_rate;
       hwif->ide_dma_lostirq = &pdc202xx_ide_dma_lostirq;

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