Re: [PATCH 0/4] g_NCR5380: PDMA fixes and cleanup
From: Finn Thain
Date: Thu Jun 22 2017 - 21:06:43 EST
On Thu, 22 Jun 2017, Ondrej Zary wrote:
> Works only with HDD on non-DTC chips. CD-ROM hangs. DTC hangs even with
> HDD. The PDMA code really needs to be fixed.
>
Does this patch help? It should be applied on top of this series of 4.
diff --git a/drivers/scsi/g_NCR5380.c b/drivers/scsi/g_NCR5380.c
index 4c31cb316a38..95ae8edbecbc 100644
--- a/drivers/scsi/g_NCR5380.c
+++ b/drivers/scsi/g_NCR5380.c
@@ -481,6 +481,30 @@ static void generic_NCR5380_release_resources(struct Scsi_Host *instance)
release_mem_region(base, region_size);
}
+/* wait_for_53c80_access - wait for 53C80 registers to become accessible
+ * @hostdata: scsi host private data
+ *
+ * The registers within the 53C80 logic block are inaccessible until
+ * bit 7 in the 53C400 control status register gets asserted.
+ */
+
+static int wait_for_53c80_access(struct NCR5380_hostdata *hostdata)
+{
+ int count = 10000;
+
+ do {
+ udelay(4); /* DTC436 chip hangs without this */
+ if (NCR5380_read(hostdata->c400_ctl_status) & CSR_53C80_REG)
+ return 0;
+ } while (--count > 0);
+
+ scmd_printk(KERN_ERR, hostdata->connected,
+ "53c80 registers not accessible, device will be reset\n");
+ NCR5380_write(hostdata->c400_ctl_status, CSR_RESET);
+ NCR5380_write(hostdata->c400_ctl_status, CSR_BASE);
+ return -1;
+}
+
/**
* generic_NCR5380_pread - pseudo DMA receive
* @hostdata: scsi host private data
@@ -493,33 +517,19 @@ static void generic_NCR5380_release_resources(struct Scsi_Host *instance)
static inline int generic_NCR5380_pread(struct NCR5380_hostdata *hostdata,
unsigned char *dst, int len)
{
- int start, retries;
- u8 csr, basr;
+ int result;
+ int start;
NCR5380_write(hostdata->c400_ctl_status, CSR_BASE | CSR_TRANS_DIR);
NCR5380_write(hostdata->c400_blk_cnt, len / 128);
for (start = 0; start < len; start += 128) {
- retries = 10000;
- while (1) { /* monitor IRQ while waiting for host buffer */
- csr = NCR5380_read(hostdata->c400_ctl_status);
- if (!(csr & CSR_HOST_BUF_NOT_RDY))
- break;
- if (csr & CSR_GATED_53C80_IRQ) {
- basr = NCR5380_read(BUS_AND_STATUS_REG);
- if (!(basr & BASR_PHASE_MATCH) ||
- (basr & BASR_BUSY_ERROR)) {
- printk("basr=0x%02x csr=0x%02x at start=%d\n", basr, csr, start);
- goto out_wait;
- }
- }
- if (retries-- < 1) {
- shost_printk(KERN_ERR, hostdata->host, "53C400r: host buffer not ready in time\n");
- NCR5380_write(hostdata->c400_ctl_status, CSR_RESET);
- NCR5380_write(hostdata->c400_ctl_status, CSR_BASE);
- goto out_wait;
- }
- }
+ if (NCR5380_poll_politely2(hostdata, hostdata->c400_ctl_status,
+ CSR_HOST_BUF_NOT_RDY, 0,
+ hostdata->c400_ctl_status,
+ CSR_GATED_53C80_IRQ,
+ CSR_GATED_53C80_IRQ, HZ / 64) < 0)
+ break;
if (hostdata->io_port && hostdata->io_width == 2)
insw(hostdata->io_port + hostdata->c400_host_buf,
@@ -532,24 +542,14 @@ static inline int generic_NCR5380_pread(struct NCR5380_hostdata *hostdata,
hostdata->io + NCR53C400_host_buffer, 128);
}
-out_wait:
- /* wait for 53C80 registers to be available */
- retries = 10000;
- while (!(NCR5380_read(hostdata->c400_ctl_status) & CSR_53C80_REG)) {
- if (retries-- < 1) {
- shost_printk(KERN_ERR, hostdata->host, "53C400r: 53C80 registers not ready in time\n");
- NCR5380_write(hostdata->c400_ctl_status, CSR_RESET);
- NCR5380_write(hostdata->c400_ctl_status, CSR_BASE);
- break;
- }
- }
+ result = wait_for_53c80_access(hostdata);
if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_END_DMA_TRANSFER))
pr_err("%s: No end dma signal (%d/%d)\n", __func__, start, len);
- hostdata->pdma_residual = len - start;
+ hostdata->pdma_residual = NCR5380_read(hostdata->c400_blk_cnt) * 128;
- return 0;
+ return result;
}
/**
@@ -564,41 +564,19 @@ static inline int generic_NCR5380_pread(struct NCR5380_hostdata *hostdata,
static inline int generic_NCR5380_pwrite(struct NCR5380_hostdata *hostdata,
unsigned char *src, int len)
{
- int start, retries;
- u8 csr, basr;
+ int result;
+ int start;
NCR5380_write(hostdata->c400_ctl_status, CSR_BASE);
NCR5380_write(hostdata->c400_blk_cnt, len / 128);
for (start = 0; start < len; start += 128) {
- retries = 10000;
- while (1) { /* monitor IRQ while waiting for host buffer */
- csr = NCR5380_read(hostdata->c400_ctl_status);
- if (!(csr & CSR_HOST_BUF_NOT_RDY))
- break;
- if (csr & CSR_GATED_53C80_IRQ) {
- basr = NCR5380_read(BUS_AND_STATUS_REG);
- if (!(basr & BASR_PHASE_MATCH) ||
- (basr & BASR_BUSY_ERROR)) {
- printk("w basr=0x%02x csr=0x%02x at start=%d\n", basr, csr, start);
- /* the previous block was not written properly */
- start -= 2 * 128;
- if (start < 0)
- start = 0;
- goto out_wait;
- }
- }
- if (retries-- < 1) {
- shost_printk(KERN_ERR, hostdata->host, "53C400w: host buffer not ready in time\n");
- NCR5380_write(hostdata->c400_ctl_status, CSR_RESET);
- NCR5380_write(hostdata->c400_ctl_status, CSR_BASE);
- /* the previous block was not written properly */
- start -= 2 * 128;
- if (start < 0)
- start = 0;
- goto out_wait;
- }
- }
+ if (NCR5380_poll_politely2(hostdata, hostdata->c400_ctl_status,
+ CSR_HOST_BUF_NOT_RDY, 0,
+ hostdata->c400_ctl_status,
+ CSR_GATED_53C80_IRQ,
+ CSR_GATED_53C80_IRQ, HZ / 64) < 0)
+ break;
if (hostdata->io_port && hostdata->io_width == 2)
outsw(hostdata->io_port + hostdata->c400_host_buf,
@@ -611,24 +589,12 @@ static inline int generic_NCR5380_pwrite(struct NCR5380_hostdata *hostdata,
src + start, 128);
}
-out_wait:
- /* wait for 53C80 registers to be available */
- udelay(4); /* DTC436 chip hangs without this */
- retries = 10000;
- while (!(NCR5380_read(hostdata->c400_ctl_status) & CSR_53C80_REG)) {
- udelay(4); /* DTC436 chip hangs without this */
- if (retries-- < 1) {
- shost_printk(KERN_ERR, hostdata->host, "53C400w: 53C80 registers not ready in time, start=%d, len=%d\n", start, len);
- NCR5380_write(hostdata->c400_ctl_status, CSR_RESET);
- NCR5380_write(hostdata->c400_ctl_status, CSR_BASE);
- break;
- }
- }
+ result = wait_for_53c80_access(hostdata);
if (!(NCR5380_read(BUS_AND_STATUS_REG) & BASR_END_DMA_TRANSFER))
pr_err("%s: No end dma signal (%d/%d)\n", __func__, start, len);
- hostdata->pdma_residual = len - start;
+ hostdata->pdma_residual = NCR5380_read(hostdata->c400_blk_cnt) * 128;
if (hostdata->pdma_residual == 0 &&
NCR5380_poll_politely(hostdata, TARGET_COMMAND_REG,
@@ -637,7 +603,7 @@ static inline int generic_NCR5380_pwrite(struct NCR5380_hostdata *hostdata,
scmd_printk(KERN_ERR, hostdata->connected,
"%s: Last Byte Sent timeout\n", __func__);
- return 0;
+ return result;
}
static int generic_NCR5380_dma_xfer_len(struct NCR5380_hostdata *hostdata,