Messages in this thread | | | Date | Wed, 19 Jun 2013 21:42:25 +0300 | From | Grygorii Strashko <> | Subject | Re: [PATCH 2/5] i2c: omap: add runtime check in isr to be sure that i2c is enabled |
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Hi Felipe, On 06/07/2013 10:02 PM, Felipe Balbi wrote: > Hi, > > On Fri, Jun 07, 2013 at 09:46:05PM +0300, Grygorii Strashko wrote: >> Add runtime check at the beginning of omap_i2c_isr/omap_i2c_isr_thread >> to be sure that i2c is enabled, before performing IRQ handling and accessing >> I2C IP registers: >> if (pm_runtime_suspended(dev->dev)) { >> WARN_ONCE(true, "We should never be here!\n"); >> return IRQ_NONE; >> } >> >> Produce warning in case if ISR called when i2c is disabled >> >> CC: Kevin Hilman <khilman@linaro.org> >> Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com> >> --- >> drivers/i2c/busses/i2c-omap.c | 10 ++++++++++ >> 1 file changed, 10 insertions(+) >> >> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c >> index 97844ff..2dac598 100644 >> --- a/drivers/i2c/busses/i2c-omap.c >> +++ b/drivers/i2c/busses/i2c-omap.c >> @@ -885,6 +885,11 @@ omap_i2c_isr(int irq, void *dev_id) >> u16 stat; >> >> spin_lock(&dev->lock); >> + if (pm_runtime_suspended(dev->dev)) { >> + WARN_ONCE(true, "We should never be here!\n"); >> + return IRQ_NONE; >> + } > returning IRQ_NONE is not what you want to do in this case. You want to > setup a flag so that your runtime_resume() knows that there are pending > events to be handled and you handle those in runtime_resume time. I don't want to handle this IRQ - we should never be here. Will be changed to IRQ_HANDLED. > > But to be frank, I don't see how this can trigger since we're calling > pm_runtime_get_sync() from omap_i2c_xfer() which means by the time > pm_runtime_get_sync() returns, assuming no errors, i2c module should be > fully resumed and ready to go. Perhaps you have found a bug somewhere > else ? May be it's better to revert this patch: e3a36b207f76364c281aeecaf14c1b22a7247278 i2c: omap: remove unnecessary pm_runtime_suspended check
which doesn't cover case when transfer is *finished*. Please, see https://patchwork.kernel.org/patch/2689211/ and cover-latter. > > Also, your 'We should never be here' message isn't helpfull at all. > >> @@ -905,6 +910,11 @@ omap_i2c_isr_thread(int this_irq, void *dev_id) >> u16 stat; >> int err = 0, count = 0; >> >> + if (pm_runtime_suspended(dev->dev)) { >> + WARN_ONCE(true, "We should never be here!\n"); >> + return IRQ_NONE; >> + } > because of IRQF_ONESHOT I can't see how this would *ever* be a valid > check. > Please, see https://patchwork.kernel.org/patch/2689211/ and cover-latter.
Sorry, for delayed reply - I've had problems with my e-mail.
- grygorii
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