ide: add ide_use_fast_pio() helper (v3)

* add ide_use_fast_pio() helper for use by host drivers

* add DMA capability and hwif->autodma checks to ide_use_dma()

  - au1xxx-ide/it8213/it821x drivers didn't check for (id->capability & 1)

    [ for the IT8211/2 in SMART mode this check shouldn't be made but since
      in it821x_fixups() we set DMA bit explicitly:

               if(strstr(id->model, "Integrated Technology Express")) {
                       /* In raid mode the ident block is slightly buggy
                          We need to set the bits so that the IDE layer knows
                          LBA28. LBA48 and DMA ar valid */
                       id->capability |= 3;            /* LBA28, DMA */

       we are better off using generic helper if we can ]

  - ide-cris driver didn't set ->autodma

    [ before the patch hwif->autodma was only checked in the chipset specific
      hwif->ide_dma_check implementations, for ide-cris it is cris_dma_check()
      function so there no behavior change here ]

v2:
* updated patch description (thanks to Alan Cox for the feedback)

v3:
* updated for scc_pata driver

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/ide.h b/include/linux/ide.h
index 40b5fa2f2627..9e1a8b9ce182 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -1352,6 +1352,7 @@ extern int ide_dma_enable(ide_drive_t *drive);
 extern char *ide_xfer_verbose(u8 xfer_rate);
 extern void ide_toggle_bounce(ide_drive_t *drive, int on);
 extern int ide_set_xfer_rate(ide_drive_t *drive, u8 rate);
+int ide_use_fast_pio(ide_drive_t *);
 
 u8 ide_dump_status(ide_drive_t *, const char *, u8);