Re: [PATCH v3] Currently if the SoC needs pinctrl to switch the SCL and SDA from the I2C function to GPIO function, the recovery won't work.

From: Yann Sionneau
Date: Tue Aug 22 2023 - 08:18:54 EST


Hi,

On 8/22/23 14:02, Andy Shevchenko wrote:
On Tue, Aug 22, 2023 at 11:15:55AM +0200, Yann Sionneau wrote:
scl-gpio = <>;
sda-gpio = <>;

Are not enough for some SoCs to have a working recovery.
Some need:

scl-gpio = <>;
sda-gpio = <>;
pinctrl-names = "default", "recovery";
pinctrl-0 = <&i2c_pins_hw>;
pinctrl-1 = <&i2c_pins_gpio>;

The driver was not filling rinfo->pinctrl with the device node
pinctrl data which is needed by generic recovery code.
...

+ rinfo->pinctrl = devm_pinctrl_get(dev->dev);
+ if (IS_ERR(rinfo->pinctrl)) {
+ if (PTR_ERR(rinfo->pinctrl) == -EPROBE_DEFER)
+ return PTR_ERR(rinfo->pinctrl);
+
+ rinfo->pinctrl = NULL;
+ dev_err(dev->dev, "getting pinctrl info failed: bus recovery might not work\n");
+ } else if (!rinfo->pinctrl) {
+ dev_dbg(dev->dev, "pinctrl is disabled, bus recovery might not work\n");
+ }
A bit of bikeshedding, would the below be slightly better?

rinfo->pinctrl = devm_pinctrl_get(dev->dev);
if (IS_ERR(rinfo->pinctrl)) {
if (PTR_ERR(rinfo->pinctrl) == -EPROBE_DEFER)
return PTR_ERR(rinfo->pinctrl);

rinfo->pinctrl = NULL;
dev_err(dev->dev, "getting pinctrl info failed, disabling...\n");

I think the dev_err() message change is not very clear because one might think that "disabling" means that the i2c adapter is getting disabled.

Maybe we can put "getting pinctrl info failed, disabling recovery..."?

}
if (!rinfo->pinctrl)
dev_dbg(dev->dev, "pinctrl is disabled, bus recovery might not work\n");

Ah yes, I like the getting rid of the `else` part. LGTM I'll re-send with that.

Regards,

--

Yann