On 03/14/2016 05:27 AM, Finn Thain wrote:
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 is redundant.
This removes another discrepancy between the two core drivers.
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/atari_NCR5380.c | 16 ++++++++--------
drivers/scsi/atari_scsi.c | 4 +++-
drivers/scsi/sun3_scsi.c | 16 ++++++----------
3 files changed, 17 insertions(+), 19 deletions(-)
Index: linux/drivers/scsi/atari_NCR5380.c
===================================================================
--- linux.orig/drivers/scsi/atari_NCR5380.c 2016-03-14 15:26:23.000000000 +1100
+++ linux/drivers/scsi/atari_NCR5380.c 2016-03-14 15:26:26.000000000 +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 2016-03-14 15:26:23.000000000 +1100
+++ linux/drivers/scsi/atari_scsi.c 2016-03-14 15:26:26.000000000 +1100
@@ -87,7 +87,6 @@
#define SUPPORT_TAGS
#define MAX_TAGS 32
-#define DMA_MIN_SIZE 32
#define NCR5380_implementation_fields /* none */
@@ -605,6 +604,9 @@ static unsigned long atari_dma_xfer_len(
{
unsigned long possible_len, limit;
+ if (wanted_len < 32)
+ 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 2016-03-14 15:26:23.000000000 +1100
+++ linux/drivers/scsi/sun3_scsi.c 2016-03-14 15:26:26.000000000 +1100
@@ -39,9 +39,6 @@
/* Definitions for the core NCR5380 driver. */
/* #define SUPPORT_TAGS */
-/* minimum number of bytes to do dma on */
-#define DMA_MIN_SIZE 129
-
/* #define MAX_TAGS 32 */
#define NCR5380_implementation_fields /* none */
@@ -61,7 +58,7 @@
#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 +259,13 @@ 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 < 129 || cmd->request->cmd_type != REQ_TYPE_FS)
return 0;
+
+ return wanted_len;
}
static inline int sun3scsi_dma_start(unsigned long count, unsigned char *data)
I still would keep the 'DMA_MIN_LEN' definition around for
sun3_scsi.c; makes it a bit more obvious what the magic number '129'
is supposed to mean.
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
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