ide: add ->dma_check method

* Add (an optional) ->dma_check method for checking if DMA can be
  used for a given command and fail DMA setup in ide_dma_prepare()
  if necessary.

* Convert alim15x3 and trm290 host drivers to use ->dma_check.

* Rename ali15x3_dma_setup() to ali_dma_check() while at it.

There should be no functional changes caused by this patch.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index cf5897f5533f..c0505e2dfc2e 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -566,9 +566,12 @@ EXPORT_SYMBOL_GPL(ide_allocate_dma_engine);
 
 int ide_dma_prepare(ide_drive_t *drive, struct ide_cmd *cmd)
 {
+        const struct ide_dma_ops *dma_ops = drive->hwif->dma_ops;
+
         if ((drive->dev_flags & IDE_DFLAG_USING_DMA) == 0 ||
+            (dma_ops->dma_check && dma_ops->dma_check(drive, cmd)) ||
             ide_build_sglist(drive, cmd) == 0 ||
-            drive->hwif->dma_ops->dma_setup(drive, cmd))
+            dma_ops->dma_setup(drive, cmd))
                 return 1;
         return 0;
 }