If the system does not come from reset (like when it is kexec()), the
regulator might have an IRQ waiting for us.

If we enable the IRQ handler before its structures are ready, we crash.

This patch fixes:

[    1.141839] Unable to handle kernel read from unreadable memory at virtual address 0000000000000078
[    1.316096] Call trace:
[    1.316101]  blocking_notifier_call_chain+0x20/0xa8
[    1.322757] cpu cpu0: dummy supplies not allowed for exclusive requests
[    1.327823]  regulator_notifier_call_chain+0x1c/0x2c
[    1.327825]  da9211_irq_handler+0x68/0xf8
[    1.327829]  irq_thread+0x11c/0x234
[    1.327833]  kthread+0x13c/0x154

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
regulator: da9211: Fix crash when irqs are pre-enabled

If the system does not come from reset (like when it is kexec()), the
regulator might have an IRQ waiting for us.

If we enable the IRQ handler before its structures are ready, we crash.

To: Support Opensource <support.opensource@diasemi.com>
To: Liam Girdwood <lgirdwood@gmail.com>
To: Mark Brown <broonie@kernel.org>
Cc: linux-kernel@vger.kernel.org
---
Changes in v2:
- Move chip_irq assignment before regulator_init (Thanks Adam)
- Reduce commit message (Thanks Mark)
- Link to v1: https://lore.kernel.org/r/20221124-da9211-v1-0-a54549aa6d3b@chromium.org
---
 drivers/regulator/da9211-regulator.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/regulator/da9211-regulator.c b/drivers/regulator/da9211-regulator.c
index e01b32d1fa17..00828f5baa97 100644
--- a/drivers/regulator/da9211-regulator.c
+++ b/drivers/regulator/da9211-regulator.c
@@ -498,6 +498,12 @@ static int da9211_i2c_probe(struct i2c_client *i2c)
 
 	chip->chip_irq = i2c->irq;
 
+	ret = da9211_regulator_init(chip);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to initialize regulator: %d\n", ret);
+		return ret;
+	}
+
 	if (chip->chip_irq != 0) {
 		ret = devm_request_threaded_irq(chip->dev, chip->chip_irq, NULL,
 					da9211_irq_handler,
@@ -512,11 +518,6 @@ static int da9211_i2c_probe(struct i2c_client *i2c)
 		dev_warn(chip->dev, "No IRQ configured\n");
 	}
 
-	ret = da9211_regulator_init(chip);
-
-	if (ret < 0)
-		dev_err(chip->dev, "Failed to initialize regulator: %d\n", ret);
-
 	return ret;
 }
 

---
base-commit: 4312098baf37ee17a8350725e6e0d0e8590252d4
change-id: 20221124-da9211-4b8904b4feb5

Best regards,
-- 
Ricardo Ribalda <ribalda@chromium.org>

On Sun, 27 Nov 2022 22:06:02 +0100, Ricardo Ribalda wrote:
> If the system does not come from reset (like when it is kexec()), the
> regulator might have an IRQ waiting for us.
> 
> If we enable the IRQ handler before its structures are ready, we crash.
> 
> This patch fixes:
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator.git for-next

Thanks!

[1/1] regulator: da9211: Use irq handler when ready
      commit: 02228f6aa6a64d588bc31e3267d05ff184d772eb

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

On Sun, Nov 27, 2022 at 10:06:02PM +0100, Ricardo Ribalda wrote:

> [    1.327829]  irq_thread+0x11c/0x234
> [    1.327833]  kthread+0x13c/0x154
> 
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
> regulator: da9211: Fix crash when irqs are pre-enabled
> 
> If the system does not come from reset (like when it is kexec()), the
> regulator might have an IRQ waiting for us.

You've included two entire changelogs here.

Hi Mark


On Mon, 28 Nov 2022 at 12:56, Mark Brown <broonie@kernel.org> wrote:
>
> On Sun, Nov 27, 2022 at 10:06:02PM +0100, Ricardo Ribalda wrote:
>
> > [    1.327829]  irq_thread+0x11c/0x234
> > [    1.327833]  kthread+0x13c/0x154
> >
> > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> > ---
> > regulator: da9211: Fix crash when irqs are pre-enabled
> >
> > If the system does not come from reset (like when it is kexec()), the
> > regulator might have an IRQ waiting for us.
>
> You've included two entire changelogs here.


Sorry

First time that I used single-message b4 send :S. I think I have fixed it.

The extra changelog comes after ---, so it should be ignored by git.
Do you want me to resend it anyway?

Thanks!


-- 
Ricardo Ribalda

On Mon, Nov 28, 2022 at 01:16:17PM +0100, Ricardo Ribalda wrote:

> First time that I used single-message b4 send :S. I think I have fixed it.
> 
> The extra changelog comes after ---, so it should be ignored by git.
> Do you want me to resend it anyway?

Hopefully git figured it out.

On 27 November 2022 21:06, Ricardo Ribalda wrote:

> Changes in v2:

That was quick! Thank you :-)

Reviewed-by: Adam Ward <DLG-Adam.Ward.opensource@dm.renesas.com>

Regards,
Adam