Messages in this thread | | | Date | Tue, 10 Jan 2023 16:01:14 +0100 | Subject | Re: [PATCH v2] extcon: usbc-tusb320: make sure the state is initialized on probe | From | Peter Rosin <> |
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Hi!
2023-01-10 at 15:14, Chanwoo Choi wrote: > Hi, > > On 22. 12. 13. 07:36, Peter Rosin wrote: >> When the port is connected at boot, there is not necessarily >> an interrupt flagged in the interrupt status register, causing >> the IRQ handler to bail out early without reading the state when >> it is invoked directly from probe. >> >> Add a flag that overrides the interrupt status register and reads >> the state regardless during probe. >> >> Fixes: 06bc4ca115cd ("extcon: Add driver for TI TUSB320") >> Signed-off-by: Peter Rosin <peda@axentia.se> >> --- >> drivers/extcon/extcon-usbc-tusb320.c | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> Hi! >> >> This is basically a resend of v1, the patch has simply been adapted >> to fit after the driver changes for type-c support. >> >> Version 1 of the patch, with its brief "discussion", is here: >> https://lore.kernel.org/lkml/ab1ad93b-4d39-8863-9704-da779fc4c426@axentia.se/ >> >> I cannot see how the patch can possibly affect detection of connector >> changes *after* 'priv->initialized = true', so the comment from Chanwoo >> Choi is still a mystery to me. The patch is about what happens *before* >> 'priv->initialized = true', i.e. when the IRQ handler is called directly >> during probe. There is no change in behavior after the statement >> 'priv->initialized = true', and IRQs are handled exactly as before once >> past that point. >> >> Please look at this patch again. >> >> Cheers, >> Peter >> >> diff --git a/drivers/extcon/extcon-usbc-tusb320.c b/drivers/extcon/extcon-usbc-tusb320.c >> index 2a120d8d3c27..dc586e5e3c65 100644 >> --- a/drivers/extcon/extcon-usbc-tusb320.c >> +++ b/drivers/extcon/extcon-usbc-tusb320.c >> @@ -78,6 +78,7 @@ struct tusb320_priv { >> struct typec_capability cap; >> enum typec_port_type port_type; >> enum typec_pwr_opmode pwr_opmode; >> + bool initialized; >> }; >> >> static const char * const tusb_attached_states[] = { >> @@ -323,7 +324,7 @@ static irqreturn_t tusb320_irq_handler(int irq, void *dev_id) >> return IRQ_NONE; >> } >> >> - if (!(reg & TUSB320_REG9_INTERRUPT_STATUS)) >> + if (priv->initialized && !(reg & TUSB320_REG9_INTERRUPT_STATUS)) >> return IRQ_NONE; >> >> tusb320_extcon_irq_handler(priv, reg); >> @@ -479,6 +480,8 @@ static int tusb320_probe(struct i2c_client *client, >> */ >> tusb320_irq_handler(client->irq, priv); >> >> + priv->initialized = true; >> + >> ret = devm_request_threaded_irq(priv->dev, client->irq, NULL, >> tusb320_irq_handler, >> IRQF_TRIGGER_FALLING | IRQF_ONESHOT, > > I think that if priv->initialized=true on probe step, > tusb32_irq_handler return the always IRQ_NONE > because priv->initialized is never changed to false.
The new behavior is to never return early when priv->initialized is false. When priv->initialized is true, the old behavior is retained through the right hand side of the && operator.
> Is it right to keep the 'priv->initialized=true' always?
Yes.
However, this patch is no longer needed. I have since noticed that the problem was later solved by Marek Vasut with 581c848b610d ("extcon: usbc-tusb320: Update state on probe even if no IRQ pending") which does pretty much the same thing as this patch, but with force_update as a function argument (and inverted logic, so "if (!forced_update && ...)" in the above if-test instead of "if (priv->initialized && ...)".)
Cheers, Peter
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