On Fri, Jan 19, 2024 at 6:59 PM Charles Keepax ckeepax@opensource.cirrus.com wrote:
On Thu, Jan 18, 2024 at 07:41:54PM +0200, andy.shevchenko@gmail.com wrote:
Fri, Aug 04, 2023 at 11:46:02AM +0100, Charles Keepax kirjoitti:
...
- BUILD_BUG_ON(ARRAY_SIZE(cs42l43_jack_override_modes) !=
ARRAY_SIZE(cs42l43_jack_text) - 1);Use static_assert() instead.
I am happy either way, but for my own education what is the reason to prefer static_assert here, is it just to be able to use == rather than !=? Or is there in general a preference to use static_assert, there is no obvious since BUILD_BUG_ON is being deprecated?
It's generally preferred since there are (known) issues with it: - it can't be put without the scope (globally); - it produces a lot of a noise and hard to read error report; - ...anything I forgot / don't know (yet) about...
BUILD_BUG_ON() might be useful in some cases, but I don't see how.
...
- ret = cs42l43_shutter_get(priv, CS42L43_STATUS_MIC_SHUTTER_MUTE_SHIFT);
- if (ret < 0)
return ret;- else if (!ret)
Reundant 'else'
ucontrol->value.integer.value[0] = ret;- else
ret = cs42l43_dapm_get_volsw(kcontrol, ucontrol);and why not positive check?
- return ret;
Or even simply as
if (ret > 0) ret = cs42l43_dapm_get_volsw(kcontrol, ucontrol); else if (ret == 0) ucontrol->value.integer.value[0] = ret; return ret;Yeah will update, that is definitely neater.
Note before doing that the last one has a downside from the
if (ret < 0) return ret; if (ret) ret = ... else ... return ret;
as it assumes that there will be no additional code in between 'if-else-if' and last 'return'. Purely a maintenance aspect, but still... So, think about it which one you would prefer,
...
- while (freq > cs42l43_pll_configs[ARRAY_SIZE(cs42l43_pll_configs) - 1].freq) {
div++;freq /= 2;- }
fls() / fls_long()?
Apologies but I might need a little bit more of a pointer here. We need to scale freq down to under 3.072MHz and I am struggling a little to see how to do that with fls.
The second argument of > operator is invariant to the loop, correct? So it can be written as (pseudocode)
y = 0; while (x > CONST) { x /= 2; y++; }
This is basically the open coded 'find the scale of x against CONST as power of 2 value'. Okay, it might be not directly fls(), but something along those types of bit operations (I believe something similar is used in spi-pxa2xx.c for calculating the divider for the Intel Quark case).
y = fls(x) - fls(CONST); // roughly looks like this, needs careful checking
...
- // Don't use devm as we need to get against the MFD device
This is weird...
- priv->mclk = clk_get_optional(cs42l43->dev, "mclk");
- if (IS_ERR(priv->mclk)) {
dev_err_probe(priv->dev, PTR_ERR(priv->mclk), "Failed to get mclk\n");goto err_pm;- }
- ret = devm_snd_soc_register_component(priv->dev, &cs42l43_component_drv,
cs42l43_dais, ARRAY_SIZE(cs42l43_dais));- if (ret) {
dev_err_probe(priv->dev, ret, "Failed to register component\n");goto err_clk;- }
- pm_runtime_mark_last_busy(priv->dev);
- pm_runtime_put_autosuspend(priv->dev);
- return 0;
+err_clk:
- clk_put(priv->mclk);
+err_pm:
- pm_runtime_put_sync(priv->dev);
- return ret;
+}
+static int cs42l43_codec_remove(struct platform_device *pdev) +{
- struct cs42l43_codec *priv = platform_get_drvdata(pdev);
- clk_put(priv->mclk);
You have clocks put before anything else, and your remove order is broken now.
To fix this (in case you may not used devm_clk_get() call), you should drop devm calls all way after the clk_get(). Do we have snd_soc_register_component()? If yes, use it to fix.
I believe you never tested rmmod/modprobe in a loop.
Hmm... will need to think this through a little bit, so might take a little longer on this one. But I guess this only becomes a problem if you attempt to remove the driver whilst you are currently playing audio, and I would expect the card tear down would stop the clock running before we get here.
I don't know the HW, it is up to you how to address this. The issue really exists and might become a hard to hunt bug (e.g., if there is an IRQ fired or async work which would like to access the HW with clock off and hang the system).