From: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx> Subject: [PATCH] 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_setup() while at it. There should be no functional changes caused by this patch. Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@xxxxxxxxx> --- drivers/ide/alim15x3.c | 9 +++++---- drivers/ide/ide-dma.c | 5 ++++- drivers/ide/trm290.c | 17 ++++++++++------- include/linux/ide.h | 1 + 4 files changed, 20 insertions(+), 12 deletions(-) Index: b/drivers/ide/alim15x3.c =================================================================== --- a/drivers/ide/alim15x3.c +++ b/drivers/ide/alim15x3.c @@ -189,20 +189,20 @@ static void ali_set_dma_mode(ide_drive_t } /** - * ali15x3_dma_setup - begin a DMA phase + * ali_dma_check - DMA check * @drive: target device * @cmd: command * * Returns 1 if the DMA cannot be performed, zero on success. */ -static int ali15x3_dma_setup(ide_drive_t *drive, struct ide_cmd *cmd) +static int ali_dma_check(ide_drive_t *drive, struct ide_cmd *cmd) { if (m5229_revision < 0xC2 && drive->media != ide_disk) { if (cmd->tf_flags & IDE_TFLAG_WRITE) return 1; /* try PIO instead of DMA */ } - return ide_dma_setup(drive, cmd); + return 0; } /** @@ -503,11 +503,12 @@ static const struct ide_port_ops ali_por static const struct ide_dma_ops ali_dma_ops = { .dma_host_set = ide_dma_host_set, - .dma_setup = ali15x3_dma_setup, + .dma_setup = ide_dma_setup, .dma_start = ide_dma_start, .dma_end = ide_dma_end, .dma_test_irq = ide_dma_test_irq, .dma_lost_irq = ide_dma_lost_irq, + .dma_check = ali_dma_check, .dma_timer_expiry = ide_dma_sff_timer_expiry, .dma_sff_read_status = ide_dma_sff_read_status, }; Index: b/drivers/ide/ide-dma.c =================================================================== --- a/drivers/ide/ide-dma.c +++ b/drivers/ide/ide-dma.c @@ -562,9 +562,12 @@ EXPORT_SYMBOL_GPL(ide_allocate_dma_engin 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; } Index: b/drivers/ide/trm290.c =================================================================== --- a/drivers/ide/trm290.c +++ b/drivers/ide/trm290.c @@ -176,19 +176,21 @@ static void trm290_selectproc (ide_drive trm290_prepare_drive(drive, !!(drive->dev_flags & IDE_DFLAG_USING_DMA)); } -static int trm290_dma_setup(ide_drive_t *drive, struct ide_cmd *cmd) +static int trm290_dma_check(ide_drive_t *drive, struct ide_cmd *cmd) { - ide_hwif_t *hwif = drive->hwif; - unsigned int count, rw; - if (cmd->tf_flags & IDE_TFLAG_WRITE) { #ifdef TRM290_NO_DMA_WRITES /* always use PIO for writes */ return 1; #endif - rw = 1; - } else - rw = 2; + } + return 0; +} + +static int trm290_dma_setup(ide_drive_t *drive, struct ide_cmd *cmd) +{ + ide_hwif_t *hwif = drive->hwif; + unsigned int count, rw = (cmd->tf_flags & IDE_TFLAG_WRITE) ? 1 : 2; count = ide_build_dmatable(drive, cmd); if (count == 0) { @@ -312,6 +314,7 @@ static struct ide_dma_ops trm290_dma_ops .dma_end = trm290_dma_end, .dma_test_irq = trm290_dma_test_irq, .dma_lost_irq = ide_dma_lost_irq, + .dma_check = trm290_dma_check, }; static const struct ide_port_info trm290_chipset __devinitdata = { Index: b/include/linux/ide.h =================================================================== --- a/include/linux/ide.h +++ b/include/linux/ide.h @@ -716,6 +716,7 @@ struct ide_dma_ops { int (*dma_test_irq)(struct ide_drive_s *); void (*dma_lost_irq)(struct ide_drive_s *); /* below ones are optional */ + int (*dma_check)(struct ide_drive_s *, struct ide_cmd *); int (*dma_timer_expiry)(struct ide_drive_s *); void (*dma_clear)(struct ide_drive_s *); /* -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html