V4L/DVB (7699): pvrusb2: Implement statistics for USB I/O performance / tracking

Implement a mechanism in the pvrusb2 driver for gathering statistics
on the stream buffering, including bytes transferred, buffers handled,
buffers in flight, etc.  This is useful for debugging certain classes
of streaming issues and for determining if the buffer pool size is
generally correct for the driver.

Signed-off-by: Mike Isely <isely@pobox.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 24 insertions, 0 deletions

diff --git a/drivers/media/video/pvrusb2/pvrusb2-debugifc.c b/drivers/media/video/pvrusb2/pvrusb2-debugifc.c
index b0687430fdd4..b53121c78ff9 100644
--- a/drivers/media/video/pvrusb2/pvrusb2-debugifc.c
+++ b/drivers/media/video/pvrusb2/pvrusb2-debugifc.c
@@ -164,6 +164,8 @@ int pvr2_debugifc_print_status(struct pvr2_hdw *hdw,
         int ccnt;
         int ret;
         u32 gpio_dir,gpio_in,gpio_out;
+        struct pvr2_stream_stats stats;
+        struct pvr2_stream *sp;
 
         ret = pvr2_hdw_is_hsm(hdw);
         ccnt = scnprintf(buf,acnt,"USB link speed: %s\n",
@@ -182,6 +184,24 @@ int pvr2_debugifc_print_status(struct pvr2_hdw *hdw,
                          pvr2_hdw_get_streaming(hdw) ? "on" : "off");
         bcnt += ccnt; acnt -= ccnt; buf += ccnt;
 
+
+        sp = pvr2_hdw_get_video_stream(hdw);
+        if (sp) {
+                pvr2_stream_get_stats(sp, &stats, 0);
+                ccnt = scnprintf(
+                        buf,acnt,
+                        "Bytes streamed=%u"
+                        " URBs: queued=%u idle=%u ready=%u"
+                        " processed=%u failed=%u\n",
+                        stats.bytes_processed,
+                        stats.buffers_in_queue,
+                        stats.buffers_in_idle,
+                        stats.buffers_in_ready,
+                        stats.buffers_processed,
+                        stats.buffers_failed);
+                bcnt += ccnt; acnt -= ccnt; buf += ccnt;
+        }
+
         return bcnt;
 }
 
@@ -220,6 +240,10 @@ static int pvr2_debugifc_do1cmd(struct pvr2_hdw *hdw,const char *buf,
                         return pvr2_hdw_cmd_decoder_reset(hdw);
                 } else if (debugifc_match_keyword(wptr,wlen,"worker")) {
                         return pvr2_hdw_untrip(hdw);
+                } else if (debugifc_match_keyword(wptr,wlen,"usbstats")) {
+                        pvr2_stream_get_stats(pvr2_hdw_get_video_stream(hdw),
+                                              NULL, !0);
+                        return 0;
                 }
                 return -EINVAL;
         } else if (debugifc_match_keyword(wptr,wlen,"cpufw")) {