[PATCH v2 1/2] firmware: cs_dsp: cs_dsp_coeff_write_ctrl() should report changed

Richard Fitzgerald
2022-11-23T16:58:26Z

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);

--
2.30.2