The am53c974 has a design flaw causing it to throw an
DMA interrupt whenever a DMA transmission completed,
even though DMA interrupt reporting is disabled.
This confuses the esp routines as it would register
a DMA interrupt whenever a cdb has been transmitted
to the drive.
So implement an option to use the FIFO for command
submission and enable it for am53c974.
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
drivers/scsi/am53c974.c | 1 +
drivers/scsi/esp_scsi.c | 83 ++++++++++++++++++++++++++++++++++++++-----------
drivers/scsi/esp_scsi.h | 1 +
3 files changed, 66 insertions(+), 19 deletions(-)
diff --git a/drivers/scsi/am53c974.c b/drivers/scsi/am53c974.c
index b9af8b0..652762e 100644
--- a/drivers/scsi/am53c974.c
+++ b/drivers/scsi/am53c974.c
@@ -401,6 +401,7 @@ static int pci_esp_probe_one(struct pci_dev *pdev,
esp->host = shost;
esp->dev = pdev;
esp->ops = &pci_esp_ops;
+ esp->flags |= ESP_FLAG_USE_FIFO;
pep->esp = esp;
if (pci_request_regions(pdev, DRV_MODULE_NAME)) {
diff --git a/drivers/scsi/esp_scsi.c b/drivers/scsi/esp_scsi.c
index 92ab921..ab7d2bc 100644
--- a/drivers/scsi/esp_scsi.c
+++ b/drivers/scsi/esp_scsi.c
@@ -605,7 +605,7 @@ static void esp_autosense(struct esp *esp, struct esp_cmd_entry *ent)
{
struct scsi_cmnd *cmd = ent->cmd;
struct scsi_device *dev = cmd->device;
- int tgt, lun;
+ int tgt, lun, i;
u8 *p, val;
tgt = dev->id;
@@ -626,7 +626,10 @@ static void esp_autosense(struct esp *esp, struct esp_cmd_entry *ent)
esp->active_cmd = ent;
- p = esp->command_block;
+ if (esp->flags & ESP_FLAG_USE_FIFO)
+ p = esp->fifo;
+ else
+ p = esp->command_block;
esp->msg_out_len = 0;
*p++ = IDENTIFY(0, lun);
@@ -648,12 +651,21 @@ static void esp_autosense(struct esp *esp, struct esp_cmd_entry *ent)
esp_write_tgt_sync(esp, tgt);
esp_write_tgt_config3(esp, tgt);
- val = (p - esp->command_block);
+ if (esp->flags & ESP_FLAG_USE_FIFO)
+ val = (p - esp->fifo);
+ else
+ val = (p - esp->command_block);
if (esp->rev == FASHME)
scsi_esp_cmd(esp, ESP_CMD_FLUSH);
- esp->ops->send_dma_cmd(esp, esp->command_block_dma,
- val, 16, 0, ESP_CMD_DMA | ESP_CMD_SELA);
+ if (esp->flags & ESP_FLAG_USE_FIFO) {
+ scsi_esp_cmd(esp, ESP_CMD_FLUSH);
+ for (i = 0; i < val; i++)
+ esp_write8(esp->fifo[i], ESP_FDATA);
+ scsi_esp_cmd(esp, ESP_CMD_SELA);
+ } else
+ esp->ops->send_dma_cmd(esp, esp->command_block_dma,
+ val, 16, 0, ESP_CMD_DMA | ESP_CMD_SELA);
}
static struct esp_cmd_entry *find_and_prep_issuable_command(struct esp *esp)
@@ -727,7 +739,10 @@ static void esp_maybe_execute_command(struct esp *esp)
esp_check_command_len(esp, cmd);
- p = esp->command_block;
+ if (esp->flags & ESP_FLAG_USE_FIFO)
+ p = esp->fifo;
+ else
+ p = esp->command_block;
esp->msg_out_len = 0;
if (tp->flags & ESP_TGT_CHECK_NEGO) {
@@ -789,13 +804,15 @@ build_identify:
}
if (!(esp->flags & ESP_FLAG_DOING_SLOWCMD)) {
- start_cmd = ESP_CMD_DMA | ESP_CMD_SELA;
+ start_cmd = ESP_CMD_SELA;
if (ent->tag[0]) {
*p++ = ent->tag[0];
*p++ = ent->tag[1];
- start_cmd = ESP_CMD_DMA | ESP_CMD_SA3;
+ start_cmd = ESP_CMD_SA3;
}
+ if (!(esp->flags & ESP_FLAG_USE_FIFO))
+ start_cmd |= ESP_CMD_DMA;
for (i = 0; i < cmd->cmd_len; i++)
*p++ = cmd->cmnd[i];
@@ -814,7 +831,9 @@ build_identify:
esp->msg_out_len += 2;
}
- start_cmd = ESP_CMD_DMA | ESP_CMD_SELAS;
+ start_cmd = ESP_CMD_SELAS;
+ if (!(esp->flags & ESP_FLAG_USE_FIFO))
+ start_cmd |= ESP_CMD_DMA;
esp->select_state = ESP_SELECT_MSGOUT;
}
val = tgt;
@@ -825,7 +844,10 @@ build_identify:
esp_write_tgt_sync(esp, tgt);
esp_write_tgt_config3(esp, tgt);
- val = (p - esp->command_block);
+ if (esp->flags & ESP_FLAG_USE_FIFO)
+ val = (p - esp->fifo);
+ else
+ val = (p - esp->command_block);
if (esp_debug & ESP_DEBUG_SCSICMD) {
printk("ESP: tgt[%d] lun[%d] scsi_cmd [ ", tgt, lun);
@@ -836,8 +858,17 @@ build_identify:
if (esp->rev == FASHME)
scsi_esp_cmd(esp, ESP_CMD_FLUSH);
- esp->ops->send_dma_cmd(esp, esp->command_block_dma,
- val, 16, 0, start_cmd);
+
+ if (esp->flags & ESP_FLAG_USE_FIFO) {
+ scsi_esp_cmd(esp, ESP_CMD_FLUSH);
+ for (i = 0; i < val; i++)
+ esp_write8(esp->fifo[i], ESP_FDATA);
+
+ scsi_esp_cmd(esp, start_cmd);
+ } else {
+ esp->ops->send_dma_cmd(esp, esp->command_block_dma,
+ val, 16, 0, start_cmd);
+ }
}
static struct esp_cmd_entry *esp_get_ent(struct esp *esp)
@@ -1646,7 +1677,7 @@ static int esp_msgin_process(struct esp *esp)
static int esp_process_event(struct esp *esp)
{
- int write;
+ int write, i;
again:
write = 0;
@@ -1872,6 +1903,10 @@ again:
if (esp->msg_out_len == 1) {
esp_write8(esp->msg_out[0], ESP_FDATA);
scsi_esp_cmd(esp, ESP_CMD_TI);
+ } else if (esp->flags & ESP_FLAG_USE_FIFO) {
+ for (i = 0; i < esp->msg_out_len; i++)
+ esp_write8(esp->msg_out[i], ESP_FDATA);
+ scsi_esp_cmd(esp, ESP_CMD_TI);
} else {
/* Use DMA. */
memcpy(esp->command_block,
@@ -1947,13 +1982,23 @@ again:
}
break;
case ESP_EVENT_CMD_START:
- memcpy(esp->command_block, esp->cmd_bytes_ptr,
- esp->cmd_bytes_left);
- if (esp->rev == FASHME)
+ if (esp->flags & ESP_FLAG_USE_FIFO) {
scsi_esp_cmd(esp, ESP_CMD_FLUSH);
- esp->ops->send_dma_cmd(esp, esp->command_block_dma,
- esp->cmd_bytes_left, 16, 0,
- ESP_CMD_DMA | ESP_CMD_TI);
+ while (esp->cmd_bytes_left) {
+ esp_write8(esp->cmd_bytes_ptr[0], ESP_FDATA);
+ esp->cmd_bytes_ptr++;
+ esp->cmd_bytes_left--;
+ }
+ scsi_esp_cmd(esp, ESP_CMD_TI);
+ } else {
+ memcpy(esp->command_block, esp->cmd_bytes_ptr,
+ esp->cmd_bytes_left);
+ if (esp->rev == FASHME)
+ scsi_esp_cmd(esp, ESP_CMD_FLUSH);
+ esp->ops->send_dma_cmd(esp, esp->command_block_dma,
+ esp->cmd_bytes_left, 16, 0,
+ ESP_CMD_DMA | ESP_CMD_TI);
+ }
esp_event(esp, ESP_EVENT_CMD_DONE);
esp->flags |= ESP_FLAG_QUICKIRQ_CHECK;
break;
diff --git a/drivers/scsi/esp_scsi.h b/drivers/scsi/esp_scsi.h
index 975d293..27dcaf8 100644
--- a/drivers/scsi/esp_scsi.h
+++ b/drivers/scsi/esp_scsi.h
@@ -478,6 +478,7 @@ struct esp {
#define ESP_FLAG_WIDE_CAPABLE 0x00000008
#define ESP_FLAG_QUICKIRQ_CHECK 0x00000010
#define ESP_FLAG_DISABLE_SYNC 0x00000020
+#define ESP_FLAG_USE_FIFO 0x00000040
u8 select_state;
#define ESP_SELECT_NONE 0x00 /* Not selecting */
--
1.8.5.2
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