On Fri, 21 Aug 2015, Arnd Bergmann wrote: > On Friday 21 August 2015 00:39:30 Petr Cvek wrote: > > Dne 20.8.2015 v 22:26 Arnd Bergmann napsal(a): > > > On Thursday 20 August 2015 21:48:20 Robert Jarzmik wrote: > > >> Petr Cvek <petr.cvek@xxxxxx> writes: > > >> > > >>> + mdelay(3); > > >> Okay, there are several mdelay(3) in this file. > > >> > > >> Could you please test if removing these mdelays prevents the camera from working > > >> ? If not, I'd like to have them removed. > > >> > > >> > > > > > > FWIW, it might be possible to replace some of them with msleep() calls, > > > potentially after replacing spinlocks with mutexes where necessary. > > > > > > Arnd > > > > > > > Datasheet says: > > > > tS:RESET Setting time after software/hardware reset 1 ms > > > > So at least one ~1 ms should be left there. Are msleep less than 20ms valid? > > > > (checkpatch: msleep < 20ms can sleep for up to 20ms) > > On most kernels, an msleep(1) will sleep somewhere between 1 and 3 milliseconds > (but could be much longer), while an mdelay(1) tries to sleep around one > millisecond, more or less. If high-res timers are available I'd suggest using usleep_range() instead. By providing suitably divergent values usleep_range de-restricts the kernel, allowing the scheduler to bundle your wake-up along with others. -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog -- To unsubscribe from this list: send the line "unsubscribe linux-leds" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
