[PATCH v2 2/2] ALSA: pcmtest: minor optimizations

From: Ivan Orlov
Date: Thu Jul 13 2023 - 04:02:27 EST


Decrease the buffer filling overhead with conditional remainder
calculation in the 'inc_buf_pos' inline function.

Fix the driver to use already defined variables where it is possible
in 'check_buf_block_ni' and 'fill_block_pattern_n' functions.

Signed-off-by: Ivan Orlov <ivan.orlov0322@xxxxxxxxx>
---
V1 -> V2:
- Split changes in the patch into two different patches

sound/drivers/pcmtest.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/sound/drivers/pcmtest.c b/sound/drivers/pcmtest.c
index e74c523e49eb..08e14b5eb772 100644
--- a/sound/drivers/pcmtest.c
+++ b/sound/drivers/pcmtest.c
@@ -144,7 +144,8 @@ static inline void inc_buf_pos(struct pcmtst_buf_iter *v_iter, size_t by, size_t
{
v_iter->total_bytes += by;
v_iter->buf_pos += by;
- v_iter->buf_pos %= bytes;
+ if (v_iter->buf_pos >= bytes)
+ v_iter->buf_pos %= bytes;
}

/*
@@ -200,10 +201,10 @@ static void check_buf_block_ni(struct pcmtst_buf_iter *v_iter, struct snd_pcm_ru
u8 current_byte;

for (i = 0; i < v_iter->b_rw; i++) {
- current_byte = runtime->dma_area[buf_pos_n(v_iter, channels, i % channels)];
+ ch_num = i % channels;
+ current_byte = runtime->dma_area[buf_pos_n(v_iter, channels, ch_num)];
if (!current_byte)
break;
- ch_num = i % channels;
if (current_byte != patt_bufs[ch_num].buf[(v_iter->total_bytes / channels)
% patt_bufs[ch_num].len]) {
v_iter->is_buf_corrupted = true;
@@ -243,7 +244,7 @@ static void fill_block_pattern_n(struct pcmtst_buf_iter *v_iter, struct snd_pcm_

for (i = 0; i < v_iter->b_rw; i++) {
ch_num = i % channels;
- runtime->dma_area[buf_pos_n(v_iter, channels, i % channels)] =
+ runtime->dma_area[buf_pos_n(v_iter, channels, ch_num)] =
patt_bufs[ch_num].buf[(v_iter->total_bytes / channels)
% patt_bufs[ch_num].len];
inc_buf_pos(v_iter, 1, runtime->dma_bytes);
--
2.34.1