isdn/gigaset: avoid copying AT commands twice

Change the Gigaset driver's internal write_cmd interface to accept a
cmdbuf structure instead of a string. This avoids copying formatted
AT commands a second time.

Impact: optimization
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 11 insertions, 40 deletions

diff --git a/drivers/isdn/gigaset/bas-gigaset.c b/drivers/isdn/gigaset/bas-gigaset.c
index 47a5ffec55a3..2dab5313913b 100644
--- a/drivers/isdn/gigaset/bas-gigaset.c
+++ b/drivers/isdn/gigaset/bas-gigaset.c
@@ -1913,65 +1913,41 @@ static int start_cbsend(struct cardstate *cs)
  * USB transmission is started if necessary.
  * parameters:
  *      cs              controller state structure
- *      buf             command string to send
- *      len             number of bytes to send (max. IF_WRITEBUF)
- *      wake_tasklet    tasklet to run when transmission is completed
- *                      (NULL if none)
+ *      cb              command buffer structure
  * return value:
  *      number of bytes queued on success
  *      error code < 0 on error
  */
-static int gigaset_write_cmd(struct cardstate *cs,
-                             const unsigned char *buf, int len,
-                             struct tasklet_struct *wake_tasklet)
+static int gigaset_write_cmd(struct cardstate *cs, struct cmdbuf_t *cb)
 {
-        struct cmdbuf_t *cb;
         unsigned long flags;
         int rc;
 
         gigaset_dbg_buffer(cs->mstate != MS_LOCKED ?
                              DEBUG_TRANSCMD : DEBUG_LOCKCMD,
-                           "CMD Transmit", len, buf);
-
-        if (len <= 0) {
-                /* nothing to do */
-                rc = 0;
-                goto notqueued;
-        }
+                           "CMD Transmit", cb->len, cb->buf);
 
         /* translate "+++" escape sequence sent as a single separate command
          * into "close AT channel" command for error recovery
          * The next command will reopen the AT channel automatically.
          */
-        if (len == 3 && !memcmp(buf, "+++", 3)) {
+        if (cb->len == 3 && !memcmp(cb->buf, "+++", 3)) {
+                kfree(cb);
                 rc = req_submit(cs->bcs, HD_CLOSE_ATCHANNEL, 0, BAS_TIMEOUT);
-                goto notqueued;
-        }
-
-        if (len > IF_WRITEBUF)
-                len = IF_WRITEBUF;
-        cb = kmalloc(sizeof(struct cmdbuf_t) + len, GFP_ATOMIC);
-        if (!cb) {
-                dev_err(cs->dev, "%s: out of memory\n", __func__);
-                rc = -ENOMEM;
-                goto notqueued;
+                if (cb->wake_tasklet)
+                        tasklet_schedule(cb->wake_tasklet);
+                return rc < 0 ? rc : cb->len;
         }
 
-        memcpy(cb->buf, buf, len);
-        cb->len = len;
-        cb->offset = 0;
-        cb->next = NULL;
-        cb->wake_tasklet = wake_tasklet;
-
         spin_lock_irqsave(&cs->cmdlock, flags);
         cb->prev = cs->lastcmdbuf;
         if (cs->lastcmdbuf)
                 cs->lastcmdbuf->next = cb;
         else {
                 cs->cmdbuf = cb;
-                cs->curlen = len;
+                cs->curlen = cb->len;
         }
-        cs->cmdbytes += len;
+        cs->cmdbytes += cb->len;
         cs->lastcmdbuf = cb;
         spin_unlock_irqrestore(&cs->cmdlock, flags);
 
@@ -1988,12 +1964,7 @@ static int gigaset_write_cmd(struct cardstate *cs,
         }
         rc = start_cbsend(cs);
         spin_unlock_irqrestore(&cs->lock, flags);
-        return rc < 0 ? rc : len;
-
-notqueued:                      /* request handled without queuing */
-        if (wake_tasklet)
-                tasklet_schedule(wake_tasklet);
-        return rc;
+        return rc < 0 ? rc : cb->len;
 }
 
 /* gigaset_write_room