brcm2708: remove linux 4.4 support

[openwrt/staging/yousong.git] / target / linux / brcm2708 / patches-4.4 / 0133-bcm2835-interpolate-audio-delay.patch

diff --git a/target/linux/brcm2708/patches-4.4/0133-bcm2835-interpolate-audio-delay.patch b/target/linux/brcm2708/patches-4.4/0133-bcm2835-interpolate-audio-delay.patch
deleted file mode 100644 (file)
index 8bf1ad8..0000000
--- a/target/linux/brcm2708/patches-4.4/0133-bcm2835-interpolate-audio-delay.patch
+++ /dev/null
@@ -1,90 +0,0 @@
-From a94c77d797c554678a37fb2b921fbab46f7f205e Mon Sep 17 00:00:00 2001
-From: wm4 <wm4@nowhere>
-Date: Wed, 13 Jan 2016 19:44:47 +0100
-Subject: [PATCH] bcm2835: interpolate audio delay
-
-It appears the GPU only sends us a message all 10ms to update
-the playback progress. Other than this, the playback position
-(what SNDRV_PCM_IOCTL_DELAY will return) is not updated at all.
-Userspace will see jitter up to 10ms in the audio position.
-
-Make this a bit nicer for userspace by interpolating the
-position using the CPU clock.
-
-I'm not sure if setting snd_pcm_runtime.delay is the right
-approach for this. Or if there is maybe an already existing
-mechanism for position interpolation in the ALSA core.
-
-I only set SNDRV_PCM_INFO_BATCH because this appears to remove
-at least one situation snd_pcm_runtime.delay is used, so I have
-to worry less in which place I have to update this field, or
-how it interacts with the rest of ALSA.
-
-In the future, it might be nice to use VC_AUDIO_MSG_TYPE_LATENCY.
-One problem is that it requires sending a videocore message, and
-waiting for a reply, which could make the implementation much
-harder due to locking and synchronization requirements.
----
- sound/arm/bcm2835-pcm.c | 12 +++++++++++-
- sound/arm/bcm2835.h     |  1 +
- 2 files changed, 12 insertions(+), 1 deletion(-)
-
---- a/sound/arm/bcm2835-pcm.c
-+++ b/sound/arm/bcm2835-pcm.c
-@@ -25,7 +25,7 @@
- /* hardware definition */
- static struct snd_pcm_hardware snd_bcm2835_playback_hw = {
-       .info = (SNDRV_PCM_INFO_INTERLEAVED | SNDRV_PCM_INFO_BLOCK_TRANSFER |
--               SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID),
-+               SNDRV_PCM_INFO_MMAP | SNDRV_PCM_INFO_MMAP_VALID | SNDRV_PCM_INFO_BATCH),
-       .formats = SNDRV_PCM_FMTBIT_U8 | SNDRV_PCM_FMTBIT_S16_LE,
-       .rates = SNDRV_PCM_RATE_CONTINUOUS | SNDRV_PCM_RATE_8000_48000,
-       .rate_min = 8000,
-@@ -99,6 +99,8 @@ static irqreturn_t bcm2835_playback_fifo
-               alsa_stream->pos %= alsa_stream->buffer_size;
-       }
- 
-+      alsa_stream->interpolate_start = ktime_get_ns();
-+
-       if (alsa_stream->substream) {
-               if (new_period)
-                       snd_pcm_period_elapsed(alsa_stream->substream);
-@@ -399,6 +401,7 @@ static int snd_bcm2835_pcm_prepare(struc
-       alsa_stream->buffer_size = snd_pcm_lib_buffer_bytes(substream);
-       alsa_stream->period_size = snd_pcm_lib_period_bytes(substream);
-       alsa_stream->pos = 0;
-+      alsa_stream->interpolate_start = ktime_get_ns();
- 
-       audio_debug("buffer_size=%d, period_size=%d pos=%d frame_bits=%d\n",
-                     alsa_stream->buffer_size, alsa_stream->period_size,
-@@ -495,6 +498,7 @@ snd_bcm2835_pcm_pointer(struct snd_pcm_s
- {
-       struct snd_pcm_runtime *runtime = substream->runtime;
-       bcm2835_alsa_stream_t *alsa_stream = runtime->private_data;
-+      u64 now = ktime_get_ns();
- 
-       audio_info(" .. IN\n");
- 
-@@ -503,6 +507,12 @@ snd_bcm2835_pcm_pointer(struct snd_pcm_s
-                     frames_to_bytes(runtime, runtime->control->appl_ptr),
-                     alsa_stream->pos);
- 
-+      /* Give userspace better delay reporting by interpolating between GPU
-+       * notifications, assuming audio speed is close enough to the clock
-+       * used for ktime */
-+      if (alsa_stream->interpolate_start && alsa_stream->interpolate_start < now)
-+              runtime->delay = -(int)div_u64((now - alsa_stream->interpolate_start) * runtime->rate,  1000000000);
-+
-       audio_info(" .. OUT\n");
-       return snd_pcm_indirect_playback_pointer(substream,
-                                                &alsa_stream->pcm_indirect,
---- a/sound/arm/bcm2835.h
-+++ b/sound/arm/bcm2835.h
-@@ -137,6 +137,7 @@ typedef struct bcm2835_alsa_stream {
-       unsigned int pos;
-       unsigned int buffer_size;
-       unsigned int period_size;
-+      u64 interpolate_start;
- 
-       uint32_t enable_fifo_irq;
-       irq_handler_t fifo_irq_handler;