ALSA: echoaudio: simplify get_audio_levels

The loop optimizer seems to go astray here, and produces some warnings
that don't seem valid.

Still, the code can be simplified -- just clear the whole array at the
beginning, and fill in whatever values are valid on the platform.

Warnings before this change (GCC 8.2.0 ARM allmodconfig):

In file included from ../sound/pci/echoaudio/gina24.c:115:
../sound/pci/echoaudio/echoaudio.c: In function 'snd_echo_vumeters_get':
../sound/pci/echoaudio/echoaudio_dsp.c:647:9: warning: iteration 1073741824 invokes undefined behavior [-Waggressive-loop-optimizations]
In file included from ../sound/pci/echoaudio/layla24.c:112:
../sound/pci/echoaudio/echoaudio.c: In function 'snd_echo_vumeters_get':
../sound/pci/echoaudio/echoaudio_dsp.c:658:9: warning: iteration 1073741824 invokes undefined behavior [-Waggressive-loop-optimizations]
../sound/pci/echoaudio/echoaudio_dsp.c:647:9: warning: iteration 1073741824 invokes undefined behavior [-Waggressive-loop-optimizations]

Signed-off-by: Olof Johansson <olof@lixom.net>
Link: https://lore.kernel.org/r/20191207224953.25944-1-olof@lixom.net
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Olof Johansson 2019-12-07 14:49:53 -08:00 committed by Takashi Iwai
parent 4cc8d6505a
commit c08f0a92f4

View File

@ -635,36 +635,30 @@ This function assumes there are no more than 16 in/out busses or pipes
Meters is an array [3][16][2] of long. */
static void get_audio_meters(struct echoaudio *chip, long *meters)
{
int i, m, n;
unsigned int i, m, n;
m = 0;
n = 0;
for (i = 0; i < num_busses_out(chip); i++, m++) {
for (i = 0 ; i < 96; i++)
meters[i] = 0;
for (m = 0, n = 0, i = 0; i < num_busses_out(chip); i++, m++) {
meters[n++] = chip->comm_page->vu_meter[m];
meters[n++] = chip->comm_page->peak_meter[m];
}
for (; n < 32; n++)
meters[n] = 0;
#ifdef ECHOCARD_ECHO3G
m = E3G_MAX_OUTPUTS; /* Skip unused meters */
#endif
for (i = 0; i < num_busses_in(chip); i++, m++) {
for (n = 32, i = 0; i < num_busses_in(chip); i++, m++) {
meters[n++] = chip->comm_page->vu_meter[m];
meters[n++] = chip->comm_page->peak_meter[m];
}
for (; n < 64; n++)
meters[n] = 0;
#ifdef ECHOCARD_HAS_VMIXER
for (i = 0; i < num_pipes_out(chip); i++, m++) {
for (n = 64, i = 0; i < num_pipes_out(chip); i++, m++) {
meters[n++] = chip->comm_page->vu_meter[m];
meters[n++] = chip->comm_page->peak_meter[m];
}
#endif
for (; n < 96; n++)
meters[n] = 0;
}