Only the atari_scsi and sun3_scsi drivers define DMA_MIN_SIZE. Both drivers also define NCR5380_dma_xfer_len, which means DMA_MIN_SIZE can be removed from the core driver. This removes another discrepancy between the two core drivers. Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx> Tested-by: Michael Schmitz <schmitzmic@xxxxxxxxx> --- Changes since v1: - Retain MIN_DMA_SIZE macro in wrapper drivers. --- drivers/scsi/atari_NCR5380.c | 16 ++++++++-------- drivers/scsi/atari_scsi.c | 6 +++++- drivers/scsi/sun3_scsi.c | 19 +++++++++---------- 3 files changed, 22 insertions(+), 19 deletions(-) Index: linux/drivers/scsi/atari_NCR5380.c =================================================================== --- linux.orig/drivers/scsi/atari_NCR5380.c 2016-03-21 13:31:10.000000000 +1100 +++ linux/drivers/scsi/atari_NCR5380.c 2016-03-21 13:31:13.000000000 +1100 @@ -1857,12 +1857,11 @@ static void NCR5380_information_transfer d = cmd->SCp.ptr; } /* this command setup for dma yet? */ - if ((count >= DMA_MIN_SIZE) && (sun3_dma_setup_done != cmd)) { - if (cmd->request->cmd_type == REQ_TYPE_FS) { - sun3scsi_dma_setup(instance, d, count, - rq_data_dir(cmd->request)); - sun3_dma_setup_done = cmd; - } + if (sun3_dma_setup_done != cmd && + sun3scsi_dma_xfer_len(count, cmd) > 0) { + sun3scsi_dma_setup(instance, d, count, + rq_data_dir(cmd->request)); + sun3_dma_setup_done = cmd; } #ifdef SUN3_SCSI_VME dregs->csr |= CSR_INTR; @@ -1927,7 +1926,7 @@ static void NCR5380_information_transfer #endif transfersize = NCR5380_dma_xfer_len(instance, cmd, phase); - if (transfersize >= DMA_MIN_SIZE) { + if (transfersize > 0) { len = transfersize; cmd->SCp.phase = phase; if (NCR5380_transfer_dma(instance, &phase, @@ -2366,7 +2365,8 @@ static void NCR5380_reselect(struct Scsi d = tmp->SCp.ptr; } /* setup this command for dma if not already */ - if ((count >= DMA_MIN_SIZE) && (sun3_dma_setup_done != tmp)) { + if (sun3_dma_setup_done != tmp && + sun3scsi_dma_xfer_len(count, tmp) > 0) { sun3scsi_dma_setup(instance, d, count, rq_data_dir(tmp->request)); sun3_dma_setup_done = tmp; Index: linux/drivers/scsi/atari_scsi.c =================================================================== --- linux.orig/drivers/scsi/atari_scsi.c 2016-03-21 13:31:10.000000000 +1100 +++ linux/drivers/scsi/atari_scsi.c 2016-03-21 13:31:13.000000000 +1100 @@ -83,11 +83,12 @@ #include <scsi/scsi_host.h> +#define DMA_MIN_SIZE 32 + /* Definitions for the core NCR5380 driver. */ #define SUPPORT_TAGS #define MAX_TAGS 32 -#define DMA_MIN_SIZE 32 #define NCR5380_implementation_fields /* none */ @@ -605,6 +606,9 @@ static unsigned long atari_dma_xfer_len( { unsigned long possible_len, limit; + if (wanted_len < DMA_MIN_SIZE) + return 0; + if (IS_A_TT()) /* TT SCSI DMA can transfer arbitrary #bytes */ return wanted_len; Index: linux/drivers/scsi/sun3_scsi.c =================================================================== --- linux.orig/drivers/scsi/sun3_scsi.c 2016-03-21 13:31:10.000000000 +1100 +++ linux/drivers/scsi/sun3_scsi.c 2016-03-21 13:31:13.000000000 +1100 @@ -36,12 +36,12 @@ #include <scsi/scsi_host.h> #include "sun3_scsi.h" -/* Definitions for the core NCR5380 driver. */ - -/* #define SUPPORT_TAGS */ /* minimum number of bytes to do dma on */ #define DMA_MIN_SIZE 129 +/* Definitions for the core NCR5380 driver. */ + +/* #define SUPPORT_TAGS */ /* #define MAX_TAGS 32 */ #define NCR5380_implementation_fields /* none */ @@ -61,7 +61,7 @@ #define NCR5380_dma_residual(instance) \ sun3scsi_dma_residual(instance) #define NCR5380_dma_xfer_len(instance, cmd, phase) \ - sun3scsi_dma_xfer_len(cmd->SCp.this_residual, cmd, !((phase) & SR_IO)) + sun3scsi_dma_xfer_len(cmd->SCp.this_residual, cmd) #define NCR5380_acquire_dma_irq(instance) (1) #define NCR5380_release_dma_irq(instance) @@ -262,14 +262,13 @@ static inline unsigned long sun3scsi_dma return last_residual; } -static inline unsigned long sun3scsi_dma_xfer_len(unsigned long wanted, - struct scsi_cmnd *cmd, - int write_flag) +static inline unsigned long sun3scsi_dma_xfer_len(unsigned long wanted_len, + struct scsi_cmnd *cmd) { - if (cmd->request->cmd_type == REQ_TYPE_FS) - return wanted; - else + if (wanted_len < DMA_MIN_SIZE || cmd->request->cmd_type != REQ_TYPE_FS) return 0; + + return wanted_len; } static inline int sun3scsi_dma_start(unsigned long count, unsigned char *data) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html