ALSA: lx6464es: fix period byte count for 16-bit streams

The lx6464es driver advertises both 16-bit and packed 24-bit PCM formats,
but lx_trigger_start() and lx_interrupt_request_new_buffer() calculate the
DMA period size as runtime->period_size * runtime->channels * 3.  That is
only correct for the packed 24-bit formats.

For 16-bit streams the driver submits buffers that are 50% larger than the
actual ALSA period and advances the DMA address by the same wrong amount.
For example, with 2 channels, 256 frames and 4 periods, the third buffer
already extends beyond the ALSA buffer and the fourth buffer starts outside
it.

Use snd_pcm_lib_period_bytes() so the byte count matches the runtime
format, channel count and period size.

Fixes: 02bec4904508 ("ALSA: lx6464es - driver for the digigram lx6464es interface")
Cc: stable@vger.kernel.org
Signed-off-by: Xu Rao <raoxu@uniontech.com>
Link: https://patch.msgid.link/8BB12E8D92A7CDBA+20260723085710.2567463-1-raoxu@uniontech.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/pci/lx6464es/lx6464es.c b/sound/pci/lx6464es/lx6464es.c
index 96df00db51d537b88b68ef73ff1fd54b6b388464..3b40ec071379ea965404ea81632a2c6455f37d79 100644 (file)
--- a/sound/pci/lx6464es/lx6464es.c
+++ b/sound/pci/lx6464es/lx6464es.c
@@ -402,11 +402,8 @@ static void lx_trigger_start(struct lx6464es *chip, struct lx_stream *lx_stream)
 
        int err;
 
-       const u32 channels = substream->runtime->channels;
-       const u32 bytes_per_frame = channels * 3;
-       const u32 period_size = substream->runtime->period_size;
        const u32 periods = substream->runtime->periods;
-       const u32 period_bytes = period_size * bytes_per_frame;
+       const u32 period_bytes = snd_pcm_lib_period_bytes(substream);
 
        dma_addr_t buf = substream->dma_buffer.addr;
        int i;

diff --git a/sound/pci/lx6464es/lx_core.c b/sound/pci/lx6464es/lx_core.c
index 6f0843cfb3be4379e4fb40a05303ced8c33a44c6..9909f10678716112979ce3f43ad7e0f5f67e3313 100644 (file)
--- a/sound/pci/lx6464es/lx_core.c
+++ b/sound/pci/lx6464es/lx_core.c
@@ -969,10 +969,7 @@ static int lx_interrupt_request_new_buffer(struct lx6464es *chip,
        const unsigned int is_capture = lx_stream->is_capture;
        int err;
 
-       const u32 channels = substream->runtime->channels;
-       const u32 bytes_per_frame = channels * 3;
-       const u32 period_size = substream->runtime->period_size;
-       const u32 period_bytes = period_size * bytes_per_frame;
+       const u32 period_bytes = snd_pcm_lib_period_bytes(substream);
        const u32 pos = lx_stream->frame_pos;
        const u32 next_pos = ((pos+1) == substream->runtime->periods) ?
                0 : pos + 1;