[PATCH v3 76/77] ncr5380: Fix wait for 53C80 registers registers after PDMA

From: Finn Thain
Date: Mon Dec 21 2015 - 21:34:49 EST


From: Ondrej Zary <linux@xxxxxxxxxxxxxxxxxxxx>

The check for 53C80 registers accessibility was commented out because
it was broken (inverted). Fix and enable it.

Signed-off-by: Ondrej Zary <linux@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>

---
drivers/scsi/g_NCR5380.c | 37 ++++++-------------------------------
1 file changed, 6 insertions(+), 31 deletions(-)

Index: linux/drivers/scsi/g_NCR5380.c
===================================================================
--- linux.orig/drivers/scsi/g_NCR5380.c 2015-12-22 12:17:31.000000000 +1100
+++ linux/drivers/scsi/g_NCR5380.c 2015-12-22 12:17:32.000000000 +1100
@@ -609,14 +609,10 @@ static inline int NCR5380_pread(struct S
if (!(NCR5380_read(hostdata->c400_ctl_status) & CSR_GATED_53C80_IRQ))
printk("53C400r: no 53C80 gated irq after transfer");

-#if 0
- /*
- * DON'T DO THIS - THEY NEVER ARRIVE!
- */
- printk("53C400r: Waiting for 53C80 registers\n");
- while (NCR5380_read(hostdata->c400_ctl_status) & CSR_53C80_REG)
+ /* wait for 53C80 registers to be available */
+ while (!(NCR5380_read(hostdata->c400_ctl_status) & CSR_53C80_REG))
;
-#endif
+
if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_END_DMA_TRANSFER))
printk(KERN_ERR "53C400r: no end dma signal\n");

@@ -638,7 +634,6 @@ static inline int NCR5380_pwrite(struct
struct NCR5380_hostdata *hostdata = shost_priv(instance);
int blocks = len / 128;
int start = 0;
- int i;

NCR5380_write(hostdata->c400_ctl_status, CSR_BASE);
NCR5380_write(hostdata->c400_blk_cnt, blocks);
@@ -687,36 +682,16 @@ static inline int NCR5380_pwrite(struct
blocks--;
}

-#if 0
- printk("53C400w: waiting for registers to be available\n");
- THEY NEVER DO ! while (NCR5380_read(hostdata->c400_ctl_status) & CSR_53C80_REG);
- printk("53C400w: Got em\n");
-#endif
-
- /* Let's wait for this instead - could be ugly */
- /* All documentation says to check for this. Maybe my hardware is too
- * fast. Waiting for it seems to work fine! KLL
- */
- while (!(i = NCR5380_read(hostdata->c400_ctl_status) & CSR_GATED_53C80_IRQ)) {
+ /* wait for 53C80 registers to be available */
+ while (!(NCR5380_read(hostdata->c400_ctl_status) & CSR_53C80_REG)) {
udelay(4); /* DTC436 chip hangs without this */
/* FIXME - no timeout */
}

- /*
- * I know. i is certainly != 0 here but the loop is new. See previous
- * comment.
- */
- if (i) {
- if (!((i = NCR5380_read(BUS_AND_STATUS_REG)) & BASR_END_DMA_TRANSFER))
- printk(KERN_ERR "53C400w: No END OF DMA bit - WHOOPS! BASR=%0x\n", i);
- } else
- printk(KERN_ERR "53C400w: no 53C80 gated irq after transfer (last block)\n");
-
-#if 0
if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_END_DMA_TRANSFER)) {
printk(KERN_ERR "53C400w: no end dma signal\n");
}
-#endif
+
while (!(NCR5380_read(TARGET_COMMAND_REG) & TCR_LAST_BYTE_SENT))
; // TIMEOUT
return 0;


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