Standardize the DMA setup hooks so that the DMA implementation in atari_NCR5380.c can be reconciled with pseudo DMA implementation in NCR5380.c. Calls to NCR5380_dma_recv_setup() and NCR5380_dma_send_setup() return a negative value on failure, zero on PDMA transfer success and a positive byte count for DMA setup success. This convention is not entirely new, but is now applied consistently. Also remove a pointless Status Register access: the *phase assignment is redundant because after NCR5380_transfer_dma() returns control to NCR5380_information_transfer(), that routine then returns control to NCR5380_main(), which means *phase is dead. Signed-off-by: Finn Thain Reviewed-by: Hannes Reinecke Tested-by: Michael Schmitz --- drivers/scsi/NCR5380.c | 21 ++++++++++----------- drivers/scsi/arm/cumana_1.c | 10 ++++++++-- drivers/scsi/arm/oak.c | 4 ++-- drivers/scsi/atari_scsi.c | 3 --- 4 files changed, 20 insertions(+), 18 deletions(-) Index: linux/drivers/scsi/NCR5380.c =================================================================== --- linux.orig/drivers/scsi/NCR5380.c 2016-03-21 13:31:21.000000000 +1100 +++ linux/drivers/scsi/NCR5380.c 2016-03-21 13:31:25.000000000 +1100 @@ -1431,7 +1431,7 @@ static int NCR5380_transfer_dma(struct S register unsigned char p = *phase; register unsigned char *d = *data; unsigned char tmp; - int foo; + int result; if ((tmp = (NCR5380_read(STATUS_REG) & PHASE_MASK)) != p) { *phase = tmp; @@ -1505,9 +1505,9 @@ static int NCR5380_transfer_dma(struct S */ if (p & SR_IO) { - foo = NCR5380_dma_recv_setup(instance, d, + result = NCR5380_dma_recv_setup(instance, d, hostdata->flags & FLAG_DMA_FIXUP ? c - 1 : c); - if (!foo && (hostdata->flags & FLAG_DMA_FIXUP)) { + if (!result && (hostdata->flags & FLAG_DMA_FIXUP)) { /* * The workaround was to transfer fewer bytes than we * intended to with the pseudo-DMA read function, wait for @@ -1525,19 +1525,19 @@ static int NCR5380_transfer_dma(struct S if (NCR5380_poll_politely(instance, BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ, HZ) < 0) { - foo = -1; + result = -1; shost_printk(KERN_ERR, instance, "PDMA read: DRQ timeout\n"); } if (NCR5380_poll_politely(instance, STATUS_REG, SR_REQ, 0, HZ) < 0) { - foo = -1; + result = -1; shost_printk(KERN_ERR, instance, "PDMA read: !REQ timeout\n"); } d[c - 1] = NCR5380_read(INPUT_DATA_REG); } } else { - foo = NCR5380_dma_send_setup(instance, d, c); - if (!foo && (hostdata->flags & FLAG_DMA_FIXUP)) { + result = NCR5380_dma_send_setup(instance, d, c); + if (!result && (hostdata->flags & FLAG_DMA_FIXUP)) { /* * Wait for the last byte to be sent. If REQ is being asserted for * the byte we're interested, we'll ACK it and it will go false. @@ -1545,7 +1545,7 @@ static int NCR5380_transfer_dma(struct S if (NCR5380_poll_politely2(instance, BUS_AND_STATUS_REG, BASR_DRQ, BASR_DRQ, BUS_AND_STATUS_REG, BASR_PHASE_MATCH, 0, HZ) < 0) { - foo = -1; + result = -1; shost_printk(KERN_ERR, instance, "PDMA write: DRQ and phase timeout\n"); } } @@ -1555,8 +1555,7 @@ static int NCR5380_transfer_dma(struct S NCR5380_read(RESET_PARITY_INTERRUPT_REG); *data = d + c; *count = 0; - *phase = NCR5380_read(STATUS_REG) & PHASE_MASK; - return foo; + return result; } /* @@ -1652,7 +1651,7 @@ static void NCR5380_information_transfer if (!cmd->device->borken) transfersize = NCR5380_dma_xfer_len(instance, cmd, phase); - if (transfersize) { + if (transfersize > 0) { len = transfersize; if (NCR5380_transfer_dma(instance, &phase, &len, (unsigned char **)&cmd->SCp.ptr)) { Index: linux/drivers/scsi/arm/cumana_1.c =================================================================== --- linux.orig/drivers/scsi/arm/cumana_1.c 2016-03-21 13:31:21.000000000 +1100 +++ linux/drivers/scsi/arm/cumana_1.c 2016-03-21 13:31:25.000000000 +1100 @@ -101,7 +101,10 @@ static inline int cumanascsi_pwrite(stru } end: writeb(priv(host)->ctrl | 0x40, priv(host)->base + CTRL); - return len; + + if (len) + return -1; + return 0; } static inline int cumanascsi_pread(struct Scsi_Host *host, @@ -163,7 +166,10 @@ static inline int cumanascsi_pread(struc } end: writeb(priv(host)->ctrl | 0x40, priv(host)->base + CTRL); - return len; + + if (len) + return -1; + return 0; } static unsigned char cumanascsi_read(struct Scsi_Host *host, unsigned int reg) Index: linux/drivers/scsi/arm/oak.c =================================================================== --- linux.orig/drivers/scsi/arm/oak.c 2016-03-21 13:31:21.000000000 +1100 +++ linux/drivers/scsi/arm/oak.c 2016-03-21 13:31:25.000000000 +1100 @@ -47,13 +47,13 @@ static inline int oakscsi_pwrite(struct void __iomem *base = priv(instance)->base; printk("writing %p len %d\n",addr, len); - if(!len) return -1; while(1) { int status; while (((status = readw(base + STAT)) & 0x100)==0); } + return 0; } static inline int oakscsi_pread(struct Scsi_Host *instance, @@ -74,7 +74,7 @@ printk("reading %p len %d\n", addr, len) if(status & 0x200 || !timeout) { printk("status = %08X\n", status); - return 1; + return -1; } } Index: linux/drivers/scsi/atari_scsi.c =================================================================== --- linux.orig/drivers/scsi/atari_scsi.c 2016-03-21 13:31:13.000000000 +1100 +++ linux/drivers/scsi/atari_scsi.c 2016-03-21 13:31:25.000000000 +1100 @@ -527,9 +527,6 @@ static unsigned long atari_scsi_dma_setu */ dma_cache_maintenance(addr, count, dir); - if (count == 0) - printk(KERN_NOTICE "SCSI warning: DMA programmed for 0 bytes !\n"); - if (IS_A_TT()) { tt_scsi_dma.dma_ctrl = dir; SCSI_DMA_WRITE_P(dma_addr, addr);