Re: [PATCH 5.10 036/530] iio:adc:ad7476: Fix remove handling

On Sat, May 15, 2021 at 10:52 PM Pavel Machek [off-list ref] wrote:

Hi!

quoted

commit 6baee4bd63f5fdf1716f88e95c21a683e94fe30d upstream.

This driver was in an odd half way state between devm based cleanup
and manual cleanup (most of which was missing).
I would guess something went wrong with a rebase or similar.
Anyhow, this basically finishes the job as a precursor to improving
the regulator handling.

I don't think this is correct:

quoted

--- a/drivers/iio/adc/ad7476.c
+++ b/drivers/iio/adc/ad7476.c

@@ -316,25 +316,15 @@ static int ad7476_probe(struct spi_devic
      spi_message_init(&st->msg);
      spi_message_add_tail(&st->xfer, &st->msg);

-     ret = iio_triggered_buffer_setup(indio_dev, NULL,
-                     &ad7476_trigger_handler, NULL);
+     ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL,
+                                           &ad7476_trigger_handler, NULL);
      if (ret)
-             goto error_disable_reg;
+             return ret;

      if (st->chip_info->reset)
              st->chip_info->reset(st);

-     ret = iio_device_register(indio_dev);
-     if (ret)
-             goto error_ring_unregister;
-     return 0;
-
-error_ring_unregister:
-     iio_triggered_buffer_cleanup(indio_dev);
-error_disable_reg:
-     regulator_disable(st->reg);
-

Regulator_disable is now removed, but we still use regulator_enable,
and we still need to keep it balanced.

Yes, but that's what this block does:
    ret = devm_add_action_or_reset(&spi->dev, ad7476_reg_disable,
                       st);
    if (ret)
        return ret;

It registers a device-managed action to disable the regulator on error
or remove.
That ad7476_reg_disable() hook was implemented on commit:
4bb2b8f94ace3 ("iio: adc: ad7476: implement devm_add_action_or_reset")

But for some reason it wasn't done correctly, as this part [in this
patch] wasn't included in the 4bb2b8f94ace3  commit.

quoted

-     return ret;
+     return devm_iio_device_register(&spi->dev, indio_dev);
 }

Best regards,
                                                                Pavel

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