V4L/DVB (10278): cx18: Fix bad audio in first analog capture.

Normalize the APU state before the second firmware load so that audio
for the first analog capture is correct.

Many thanks to Conexant for supporting me in finding a solution for this
problem.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 15 insertions, 2 deletions

diff --git a/drivers/media/video/cx18/cx18-driver.c b/drivers/media/video/cx18/cx18-driver.c
index 7e455fdcf77..e161d29beb7 100644
--- a/drivers/media/video/cx18/cx18-driver.c
+++ b/drivers/media/video/cx18/cx18-driver.c
@@ -1043,8 +1043,21 @@ int cx18_init_on_first_open(struct cx18 *cx)
         }
         set_bit(CX18_F_I_LOADED_FW, &cx->i_flags);
 
-        /* Init the firmware twice to work around a silicon bug
-         * transport related. */
+        /*
+         * Init the firmware twice to work around a silicon bug
+         * with the digital TS.
+         *
+         * The second firmware load requires us to normalize the APU state,
+         * or the audio for the first analog capture will be badly incorrect.
+         *
+         * I can't seem to call APU_RESETAI and have it succeed without the
+         * APU capturing audio, so we start and stop it here to do the reset
+         */
+
+        /* MPEG Encoding, 224 kbps, MPEG Layer II, 48 ksps */
+        cx18_vapi(cx, CX18_APU_START, 2, CX18_APU_ENCODING_METHOD_MPEG|0xb9, 0);
+        cx18_vapi(cx, CX18_APU_RESETAI, 0);
+        cx18_vapi(cx, CX18_APU_STOP, 1, CX18_APU_ENCODING_METHOD_MPEG);
 
         fw_retry_count = 3;
         while (--fw_retry_count > 0) {