From: Simon Trimmer simont@opensource.cirrus.com
ALSA callers need to know whether there was a change to the value so that they can report a control write change correctly.
Signed-off-by: Simon Trimmer simont@opensource.cirrus.com Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com --- drivers/firmware/cirrus/cs_dsp.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-)
diff --git a/drivers/firmware/cirrus/cs_dsp.c b/drivers/firmware/cirrus/cs_dsp.c index 81cc3d0f6eec..17b7198b87dc 100644 --- a/drivers/firmware/cirrus/cs_dsp.c +++ b/drivers/firmware/cirrus/cs_dsp.c @@ -752,7 +752,7 @@ static int cs_dsp_coeff_write_ctrl_raw(struct cs_dsp_coeff_ctl *ctl, * * Must be called with pwr_lock held. * - * Return: Zero for success, a negative number on error. + * Return: < 0 on error, 1 when the control value changed and 0 when it has not. */ int cs_dsp_coeff_write_ctrl(struct cs_dsp_coeff_ctl *ctl, unsigned int off, const void *buf, size_t len) @@ -767,16 +767,23 @@ int cs_dsp_coeff_write_ctrl(struct cs_dsp_coeff_ctl *ctl, if (len + off * sizeof(u32) > ctl->len) return -EINVAL;
- if (ctl->flags & WMFW_CTL_FLAG_VOLATILE) + if (ctl->flags & WMFW_CTL_FLAG_VOLATILE) { ret = -EPERM; - else if (buf != ctl->cache) - memcpy(ctl->cache + off * sizeof(u32), buf, len); + } else if (buf != ctl->cache) { + if (memcmp(ctl->cache + off * sizeof(u32), buf, len)) + memcpy(ctl->cache + off * sizeof(u32), buf, len); + else + return 0; + }
ctl->set = 1; if (ctl->enabled && ctl->dsp->running) ret = cs_dsp_coeff_write_ctrl_raw(ctl, off, buf, len);
- return ret; + if (ret < 0) + return ret; + + return 1; } EXPORT_SYMBOL_GPL(cs_dsp_coeff_write_ctrl);