[media] anysee: repeat failed USB control messages

Control message load increased heavily after CI/CAM support due
to dvb_ca_en50221. It looks like CI/CAM drops to non-working
state easily after error is returned to its callbacks. Due to
that, add some logic to avoid errors repeating failed messages.

Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/dvb/dvb-usb/anysee.c b/drivers/media/dvb/dvb-usb/anysee.c
index cf0c318d6989e11eda05286c7dd209e8e41fc673..03c28655af1be54eec6e10486ab5fa71ccc58787 100644 (file)
--- a/drivers/media/dvb/dvb-usb/anysee.c
+++ b/drivers/media/dvb/dvb-usb/anysee.c
@@ -58,7 +58,7 @@ static int anysee_ctrl_msg(struct dvb_usb_device *d, u8 *sbuf, u8 slen,
        u8 *rbuf, u8 rlen)
 {
        struct anysee_state *state = d->priv;
-       int act_len, ret;
+       int act_len, ret, i;
        u8 buf[64];
 
        memcpy(&buf[0], sbuf, slen);
@@ -73,26 +73,52 @@ static int anysee_ctrl_msg(struct dvb_usb_device *d, u8 *sbuf, u8 slen,
        /* We need receive one message more after dvb_usb_generic_rw due
           to weird transaction flow, which is 1 x send + 2 x receive. */
        ret = dvb_usb_generic_rw(d, buf, sizeof(buf), buf, sizeof(buf), 0);
-       if (!ret) {
+       if (ret)
+               goto error_unlock;
+
+       /* TODO FIXME: dvb_usb_generic_rw() fails rarely with error code -32
+        * (EPIPE, Broken pipe). Function supports currently msleep() as a
+        * parameter but I would not like to use it, since according to
+        * Documentation/timers/timers-howto.txt it should not be used such
+        * short, under < 20ms, sleeps. Repeating failed message would be
+        * better choice as not to add unwanted delays...
+        * Fixing that correctly is one of those or both;
+        * 1) use repeat if possible
+        * 2) add suitable delay
+        */
+
+       /* get answer, retry few times if error returned */
+       for (i = 0; i < 3; i++) {
                /* receive 2nd answer */
                ret = usb_bulk_msg(d->udev, usb_rcvbulkpipe(d->udev,
                        d->props.generic_bulk_ctrl_endpoint), buf, sizeof(buf),
                        &act_len, 2000);
-               if (ret)
-                       err("%s: recv bulk message failed: %d", __func__, ret);
-               else {
+
+               if (ret) {
+                       deb_info("%s: recv bulk message failed: %d",
+                                       __func__, ret);
+               } else {
                        deb_xfer("<<< ");
                        debug_dump(buf, rlen, deb_xfer);
 
                        if (buf[63] != 0x4f)
                                deb_info("%s: cmd failed\n", __func__);
+
+                       break;
                }
        }
 
+       if (ret) {
+               /* all retries failed, it is fatal */
+               err("%s: recv bulk message failed: %d", __func__, ret);
+               goto error_unlock;
+       }
+
        /* read request, copy returned data to return buf */
-       if (!ret && rbuf && rlen)
+       if (rbuf && rlen)
                memcpy(rbuf, buf, rlen);
 
+error_unlock:
        mutex_unlock(&anysee_usb_mutex);
 
        return ret;