2025. 08. 11. 22:17 keltezéssel, Andy Shevchenko írta:
On Mon, Aug 11, 2025 at 09:49:55PM +0200, Gabor Juhos wrote:
Add a new init_recovery() callback to struct 'i2c_bus_recovery_info' and modify the i2c_init_recovery() function to call that if specified instead of the generic i2c_gpio_init_recovery() function.
This allows controller drivers to skip calling the generic code by implementing a dummy callback function, or alternatively to run a fine tuned custom implementation.
This is needed for the 'i2c-pxa' driver in order to be able to fix a long standing bug for which the fix will be implemented in a
followup patch.
"...next change."
Ok.
...
The first traditional question is why the generic recovery is not working.
The details are in the driver specific patches. Should I write it all down here too?
...
- if (i2c_gpio_init_recovery(adap) == -EPROBE_DEFER)
- if (bri->init_recovery) {
ret = bri->init_recovery(adap);if (ret)return ret;
- } else if (i2c_gpio_init_recovery(adap) == -EPROBE_DEFER) { return -EPROBE_DEFER;
- }
If the above stays, I think we would drop the last and always have init_recovery to be assigned.
In that case we would have something like this:
if (!bri->init_recovery) bri->init_recovery = i2c_gpio_init_recovery;
ret = bri->init_recovery(adap); if (ret) return ret;
Since the callback is used only once, and within the same fuction where it is assigned, I don't really see the advantage of the assignment. Although it definitely looks cleaner as far as error handling is concerned.
Originally, I have used the following solution:
if (bri->init_recovery) ret = bri->init_recovery(adap); else ret = i2c_gpio_init_recovery(adap);
if (ret) return ret;
However the existing code ignores errors from i2c_gpio_init_recovery() except EPROBE_DEFER, so I changed this to the code proposed in the patch in order to keep the existing behaviour.
Regards, Gabor