ide-dma: fix ide_build_dmatable() for TRM290

Apparently, 'xcount' being 0 does not mean 0 bytes for TRM290; it means 4 bytes,
judging from the code immediately preceding this check.  So, we must never try
to "split" the PRD for TRM290.

This is probably never hit anyway -- with the DMA buffers aligned to at least
512 bytes and ATAPI DMA not being used for non block I/O commands...

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

diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index adc6827..3fa07c0 100644 (file)
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -211,7 +211,7 @@ int ide_build_dmatable (ide_drive_t *drive, struct request *rq)
                                xcount = bcount & 0xffff;
                                if (is_trm290)
                                        xcount = ((xcount >> 2) - 1) << 16;
-                               if (xcount == 0x0000) {
+                               else if (xcount == 0x0000) {
        /* 
         * Most chipsets correctly interpret a length of 0x0000 as 64KB,
         * but at least one (e.g. CS5530) misinterprets it as zero (!).