Messages in this thread | | | Subject | Re: [PATCH V2 1/5] usb: serial: f81534: add high baud rate support | From | "Ji-Ze Hong (Peter Hong)" <> | Date | Wed, 10 Jan 2018 17:16:01 +0800 |
| |
Hi Johan,
Johan Hovold 於 2018/1/10 下午 04:49 寫道: >> Normally, the communication with F81534 ep0 will take less than 1 sec >> (even only some milliseconds), but It maybe take much long time with >> huge loading with UART functional. >> >> We had tested it on BurnInTest, 4 ports with 921600bps + MSR status >> check to perform huge loading test. The worst case to read MSR register >> via ep0 will take 15~18 seconds. So We'll still remain the max waiting >> time for access ep0 with 2x10=20s in high baud rate mode. > > Wow, that's unfortunate. But note that your patch only doubles the > timeout to 2000 ms, that is, two seconds and not twenty: > > -#define F81534_USB_TIMEOUT 1000 > +#define F81534_USB_TIMEOUT 2000 > > If you really intended to increase this to twenty seconds, then please > do so in a separate (preparatory) patch where you describe why that is > needed (e.g. what you wrote above).
In f81534_set_register()/f81534_get_register(), We'll use a while loop with 10 times to get/set register and the timeout is 1000ms. So the total minimum retry timeout is 1000x10=10s.
But when introducing the high baud rate support, 10s is not enough for heavily loading. We had tested the minimum retry is 16~18s, so we enlarge the F81534_USB_TIMEOUT from 1000 to 2000 and the total minimum retry timeout is 20s.
Should I separate it as 2 patches? This issue is due to introducing high baud patch.
Thanks -- With Best Regards, Peter Hong
| |