scsi: esp_scsi: Eliminate ESP_FLAG_DOING_SLOWCMD

The concept of a 'slow command' as it appears in esp_scsi is confusing
because it could refer to an ESP command or a SCSI command. It turns out
that it refers to a particular ESP select command which the driver also
tracks as 'ESP_SELECT_MSGOUT'. For readability, it is better to use the
terminology from the datasheets.

The global ESP_FLAG_DOING_SLOWCMD flag is redundant anyway, as it can be
inferred from esp->select_state. Remove the ESP_FLAG_DOING_SLOWCMD cruft
and just use a boolean local variable.

Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/esp_scsi.c b/drivers/scsi/esp_scsi.c
index 692461443103fd536a5309aed54969af542c06d7..752857dc643796b2bbfdbeec64b44bef28a3eae7 100644 (file)
--- a/drivers/scsi/esp_scsi.c
+++ b/drivers/scsi/esp_scsi.c
@@ -482,17 +482,6 @@ static void esp_restore_pointers(struct esp *esp, struct esp_cmd_entry *ent)
        spriv->tot_residue = ent->saved_tot_residue;
 }
 
-static void esp_check_command_len(struct esp *esp, struct scsi_cmnd *cmd)
-{
-       if (cmd->cmd_len == 6 ||
-           cmd->cmd_len == 10 ||
-           cmd->cmd_len == 12) {
-               esp->flags &= ~ESP_FLAG_DOING_SLOWCMD;
-       } else {
-               esp->flags |= ESP_FLAG_DOING_SLOWCMD;
-       }
-}
-
 static void esp_write_tgt_config3(struct esp *esp, int tgt)
 {
        if (esp->rev > ESP100A) {
@@ -739,6 +728,7 @@ static void esp_maybe_execute_command(struct esp *esp)
        struct scsi_device *dev;
        struct scsi_cmnd *cmd;
        struct esp_cmd_entry *ent;
+       bool select_and_stop = false;
        int tgt, lun, i;
        u32 val, start_cmd;
        u8 *p;
@@ -769,7 +759,8 @@ static void esp_maybe_execute_command(struct esp *esp)
        esp_map_dma(esp, cmd);
        esp_save_pointers(esp, ent);
 
-       esp_check_command_len(esp, cmd);
+       if (!(cmd->cmd_len == 6 || cmd->cmd_len == 10 || cmd->cmd_len == 12))
+               select_and_stop = true;
 
        p = esp->command_block;
 
@@ -810,9 +801,9 @@ static void esp_maybe_execute_command(struct esp *esp)
                        tp->flags &= ~ESP_TGT_CHECK_NEGO;
                }
 
-               /* Process it like a slow command.  */
-               if (tp->flags & (ESP_TGT_NEGO_WIDE | ESP_TGT_NEGO_SYNC))
-                       esp->flags |= ESP_FLAG_DOING_SLOWCMD;
+               /* If there are multiple message bytes, use Select and Stop */
+               if (esp->msg_out_len)
+                       select_and_stop = true;
        }
 
 build_identify:
@@ -822,23 +813,10 @@ build_identify:
                /* ESP100 lacks select w/atn3 command, use select
                 * and stop instead.
                 */
-               esp->flags |= ESP_FLAG_DOING_SLOWCMD;
+               select_and_stop = true;
        }
 
-       if (!(esp->flags & ESP_FLAG_DOING_SLOWCMD)) {
-               start_cmd = ESP_CMD_SELA;
-               if (ent->tag[0]) {
-                       *p++ = ent->tag[0];
-                       *p++ = ent->tag[1];
-
-                       start_cmd = ESP_CMD_SA3;
-               }
-
-               for (i = 0; i < cmd->cmd_len; i++)
-                       *p++ = cmd->cmnd[i];
-
-               esp->select_state = ESP_SELECT_BASIC;
-       } else {
+       if (select_and_stop) {
                esp->cmd_bytes_left = cmd->cmd_len;
                esp->cmd_bytes_ptr = &cmd->cmnd[0];
 
@@ -853,6 +831,19 @@ build_identify:
 
                start_cmd = ESP_CMD_SELAS;
                esp->select_state = ESP_SELECT_MSGOUT;
+       } else {
+               start_cmd = ESP_CMD_SELA;
+               if (ent->tag[0]) {
+                       *p++ = ent->tag[0];
+                       *p++ = ent->tag[1];
+
+                       start_cmd = ESP_CMD_SA3;
+               }
+
+               for (i = 0; i < cmd->cmd_len; i++)
+                       *p++ = cmd->cmnd[i];
+
+               esp->select_state = ESP_SELECT_BASIC;
        }
        val = tgt;
        if (esp->rev == FASHME)
@@ -1260,7 +1251,6 @@ static int esp_finish_select(struct esp *esp)
                        esp_unmap_dma(esp, cmd);
                        esp_free_lun_tag(ent, cmd->device->hostdata);
                        tp->flags &= ~(ESP_TGT_NEGO_SYNC | ESP_TGT_NEGO_WIDE);
-                       esp->flags &= ~ESP_FLAG_DOING_SLOWCMD;
                        esp->cmd_bytes_ptr = NULL;
                        esp->cmd_bytes_left = 0;
                } else {
@@ -1308,9 +1298,8 @@ static int esp_finish_select(struct esp *esp)
                                esp_flush_fifo(esp);
                }
 
-               /* If we are doing a slow command, negotiation, etc.
-                * we'll do the right thing as we transition to the
-                * next phase.
+               /* If we are doing a Select And Stop command, negotiation, etc.
+                * we'll do the right thing as we transition to the next phase.
                 */
                esp_event(esp, ESP_EVENT_CHECK_PHASE);
                return 0;

diff --git a/drivers/scsi/esp_scsi.h b/drivers/scsi/esp_scsi.h
index 8062b536cbffe1a7affd10e6174f801429b4921d..81125ecd597cec10e8d0e265d73f7915b9df424a 100644 (file)
--- a/drivers/scsi/esp_scsi.h
+++ b/drivers/scsi/esp_scsi.h
@@ -473,7 +473,6 @@ struct esp {
        u32                     flags;
 #define ESP_FLAG_DIFFERENTIAL  0x00000001
 #define ESP_FLAG_RESETTING     0x00000002
-#define ESP_FLAG_DOING_SLOWCMD 0x00000004
 #define ESP_FLAG_WIDE_CAPABLE  0x00000008
 #define ESP_FLAG_QUICKIRQ_CHECK        0x00000010
 #define ESP_FLAG_DISABLE_SYNC  0x00000020
@@ -516,7 +515,7 @@ struct esp {
        u32                     min_period;
        u32                     radelay;
 
-       /* Slow command state.  */
+       /* ESP_CMD_SELAS command state */
        u8                      *cmd_bytes_ptr;
        int                     cmd_bytes_left;