V4L/DVB (5174): Pvrusb2: video corruption fixes

Tweak the encoder setup in order to stop it from corrupting the video
data when there is a disruption in the data flow (e.g. a channel change).

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

1 files changed, 69 insertions, 0 deletions

diff --git a/drivers/media/video/pvrusb2/pvrusb2-encoder.c b/drivers/media/video/pvrusb2/pvrusb2-encoder.c
index 7cd95e9f914d..5fe17c0344b2 100644
--- a/drivers/media/video/pvrusb2/pvrusb2-encoder.c
+++ b/drivers/media/video/pvrusb2/pvrusb2-encoder.c
@@ -321,6 +321,73 @@ static int pvr2_encoder_vcmd(struct pvr2_hdw *hdw, int cmd,
         return pvr2_encoder_cmd(hdw,cmd,args,0,data);
 }
 
+
+/* This implements some extra setup for the encoder that seems to be
+   specific to the PVR USB2 hardware. */
+int pvr2_encoder_prep_config(struct pvr2_hdw *hdw)
+{
+        int ret = 0;
+        int encMisc3Arg = 0;
+
+#if 0
+        /* This inexplicable bit happens in the Hauppage windows
+           driver (for both 24xxx and 29xxx devices).  However I
+           currently see no difference in behavior with or without
+           this stuff.  Leave this here as a note of its existence,
+           but don't use it. */
+        LOCK_TAKE(hdw->ctl_lock); do {
+                u32 dat[1];
+                dat[0] = 0x80000640;
+                pvr2_encoder_write_words(hdw,0x01fe,dat,1);
+                pvr2_encoder_write_words(hdw,0x023e,dat,1);
+        } while(0); LOCK_GIVE(hdw->ctl_lock);
+#endif
+
+        /* Mike Isely <isely@pobox.com> 26-Jan-2006 The windows driver
+           sends the following list of ENC_MISC commands (for both
+           24xxx and 29xxx devices).  Meanings are not entirely clear,
+           however without the ENC_MISC(3,1) command then we risk
+           random perpetual video corruption whenever the video input
+           breaks up for a moment (like when switching channels). */
+
+
+#if 0
+        /* This ENC_MISC(5,0) command seems to hurt 29xxx sync
+           performance on channel changes, but is not a problem on
+           24xxx devices. */
+        ret |= pvr2_encoder_vcmd(hdw, CX2341X_ENC_MISC,4, 5,0,0,0);
+#endif
+
+        /* This ENC_MISC(3,encMisc3Arg) command is critical - without
+           it there will eventually be video corruption.  Also, the
+           29xxx case is strange - the Windows driver is passing 1
+           regardless of device type but if we have 1 for 29xxx device
+           the video turns sluggish.  */
+        switch (hdw->hdw_type) {
+        case PVR2_HDW_TYPE_24XXX: encMisc3Arg = 1; break;
+        case PVR2_HDW_TYPE_29XXX: encMisc3Arg = 0; break;
+        default: break;
+        }
+        ret |= pvr2_encoder_vcmd(hdw, CX2341X_ENC_MISC,4, 3,
+                                 encMisc3Arg,0,0);
+
+        ret |= pvr2_encoder_vcmd(hdw, CX2341X_ENC_MISC,4, 8,0,0,0);
+
+#if 0
+        /* This ENC_MISC(4,1) command is poisonous, so it is commented
+           out.  But I'm leaving it here anyway to document its
+           existence in the Windows driver.  The effect of this
+           command is that apps displaying the stream become sluggish
+           with stuttering video. */
+        ret |= pvr2_encoder_vcmd(hdw, CX2341X_ENC_MISC,4, 4,1,0,0);
+#endif
+
+        ret |= pvr2_encoder_vcmd(hdw, CX2341X_ENC_MISC,4, 0,3,0,0);
+        ret |= pvr2_encoder_vcmd(hdw, CX2341X_ENC_MISC,4,15,0,0,0);
+
+        return ret;
+}
+
 int pvr2_encoder_configure(struct pvr2_hdw *hdw)
 {
         int ret;
@@ -335,6 +402,8 @@ int pvr2_encoder_configure(struct pvr2_hdw *hdw)
 
         ret = 0;
 
+        ret |= pvr2_encoder_prep_config(hdw);
+
         if (!ret) ret = pvr2_encoder_vcmd(
                 hdw,CX2341X_ENC_SET_NUM_VSYNC_LINES, 2,
                 0xf0, 0xf0);