Hi Heiko, ? 2016/12/5 18:54, Heiko Stuebner ??: > Hi David, > > Am Montag, 5. Dezember 2016, 16:02:59 CET schrieb David Wu: >> During suspend there may still be some i2c access happening. >> And if we don't keep i2c irq ON, there may be i2c access timeout if >> i2c is in irq mode of operation. > > can you describe the issue you're trying to fix a bit more please? Sometimes we could see the i2c timeout errors during suspend/resume, which makes the duration of suspend/resume too longer. [ 484.171541] CPU4: Booted secondary processor [410fd082] [ 485.172777] rk3x-i2c ff3c0000.i2c: timeout, ipd: 0x10, state: 1 [ 486.172760] rk3x-i2c ff3c0000.i2c: timeout, ipd: 0x10, state: 1 [ 487.172759] rk3x-i2c ff3c0000.i2c: timeout, ipd: 0x10, state: 1 [ 487.172840] cpu cpu4: _set_opp_voltage: failed to set voltage (800000 800000 800000 mV): -110 [ 487.172874] cpu cpu4: failed to set volt 800000 > > I.e. I'd think the i2c-core does suspend i2c-client devices first, so that > these should be able to finish up their ongoing transfers and not start any > new ones instead? > > Your irq can still happen slightly after the system started going to actually > sleep, so to me it looks like you just widened the window where irqs can be > handled. Especially as your irq could also just simply stem from the start > state, so you cannot even be sure if your transaction actually is finished. Okay, you are right. I want to give it a double insurance at first, but it may hide the unhappend issue. > > So to me it looks like the i2c-connected device driver should be fixed instead? I tell them to fix it in rk808 driver. > > In the past I solved this for example in the zforce_ts driver [0] to > prevent i2c transfers from happening during suspend. > > > Heiko > > [0] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/drivers/input/touchscreen/zforce_ts.c > > >> >> Signed-off-by: David Wu <david.wu at rock-chips.com> >> --- >> drivers/i2c/busses/i2c-rk3x.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c >> index df22066..67af32a 100644 >> --- a/drivers/i2c/busses/i2c-rk3x.c >> +++ b/drivers/i2c/busses/i2c-rk3x.c >> @@ -1261,7 +1261,7 @@ static int rk3x_i2c_probe(struct platform_device >> *pdev) } >> >> ret = devm_request_irq(&pdev->dev, irq, rk3x_i2c_irq, >> - 0, dev_name(&pdev->dev), i2c); >> + IRQF_NO_SUSPEND, dev_name(&pdev->dev), i2c); >> if (ret < 0) { >> dev_err(&pdev->dev, "cannot request IRQ\n"); >> return ret; > > > > >
