V4L/DVB (6045): ivtv: fix handling of INITIALIZE_INPUT fw call

The CX2341X_ENC_INITIALIZE_INPUT firmware call requires careful handling,
otherwise the computer can freeze or the top-third of the screen can start
flickering. This patch ensures that CX2341X_ENC_INITIALIZE_INPUT is called
at the right time and in the right way.

In addition the stop capture handling was improved so that the last pending
DMA transfer is also processed. Otherwise this would be the first data that
arrived when a new capture was started which is not what you want.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 11 insertions, 8 deletions

diff --git a/drivers/media/video/ivtv/ivtv-fileops.c b/drivers/media/video/ivtv/ivtv-fileops.c
index 9e867b5229d..908e640c274 100644
--- a/drivers/media/video/ivtv/ivtv-fileops.c
+++ b/drivers/media/video/ivtv/ivtv-fileops.c
@@ -892,12 +892,20 @@ int ivtv_v4l2_open(struct inode *inode, struct file *filp)
                         return -EBUSY;
                 }
 
+                if (!test_bit(IVTV_F_I_RADIO_USER, &itv->i_flags)) {
+                        if (atomic_read(&itv->capturing) > 0) {
+                                /* switching to radio while capture is
+                                   in progress is not polite */
+                                kfree(item);
+                                return -EBUSY;
+                        }
+                }
+                /* Mark that the radio is being used. */
+                set_bit(IVTV_F_I_RADIO_USER, &itv->i_flags);
                 /* We have the radio */
                 ivtv_mute(itv);
                 /* Switch tuner to radio */
                 ivtv_call_i2c_clients(itv, AUDC_SET_RADIO, NULL);
-                /* Mark that the radio is being used. */
-                set_bit(IVTV_F_I_RADIO_USER, &itv->i_flags);
                 /* Select the correct audio input (i.e. radio tuner) */
                 ivtv_audio_set_io(itv);
                 if (itv->hw_flags & IVTV_HW_SAA711X)
@@ -931,13 +939,8 @@ void ivtv_mute(struct ivtv *itv)
 
 void ivtv_unmute(struct ivtv *itv)
 {
-        /* initialize or refresh input */
-        if (atomic_read(&itv->capturing) == 0)
-                ivtv_vapi(itv, CX2341X_ENC_INITIALIZE_INPUT, 0);
-
-        ivtv_msleep_timeout(100, 0);
-
         if (atomic_read(&itv->capturing)) {
+                ivtv_msleep_timeout(100, 0);
                 ivtv_vapi(itv, CX2341X_ENC_MISC, 1, 12);
                 ivtv_vapi(itv, CX2341X_ENC_MUTE_AUDIO, 1, 0);
         }