My work in Eddi De Pieri <eddi@xxxxxxxxxxx> wrote: > Bus 003 Device 014: ID 1a86:7523 QinHeng Electronics HL-340 USB-Serial > adapter > > ch431 kernel driver don't work correctly with this device, > when URB_FUNCTION_BULK_OR_INTERRUPT_TRANSFER answer/send wrong character > > After some experiment by passing command retrieved from usbsnoop log > it seems that ch341.c starts working if comment out following line > > // r = ch341_control_out(dev, 0x9a, 0x2518, 0x0050); > > my windows driver usbsnoop | grep "18 25" > 000007: 000003 ms 000398 ms c0 95 18 25 00 00 02 00 <<< c3 00 > 000036: 000004 ms 000620 ms 40 9a 18 25 c2 00 00 00 >>> > 000075: 000003 ms 011673 ms 40 9a 18 25 c3 00 00 00 >>> > > as you can see I get c3 while who first logged windows driver sniff get > 56. My work in progress updates to this driver had already marked that line as suspicious. My draft comment is "this sets break + 5 bit mode, why?!" On a ch340, this _should_ have just been ignored, as it doesn't support 5 bit mode. Also, "break" on this device is actually by disabling the rx and tx sides, there's a bit in that register for both directions to be enabled individually. It's a little sad that your hl340 device fails, as those are the only ones that have been working for me so far. ch341 devices don't work reliably at all. > please note that my device after following command > r = ch341_control_in(dev, 0x5f, 0, 0, buffer, size); ( > answer 0x3000, so it should be a more recent hardware version. > > ch34x linux driver from the oem confirmed that 0x5f means hardware > version) > > I need someone that have same device or other devices that needs > ch341.ko to check that it works properly even if you comment out > before sending a patch back to the ML. > It needs a lot more than just commenting out that line unfortunately. Good news, I'm working on this again, bad news, I said that 6 months ago too :( My current work is at https://github.com/karlp/linux/tree/ch341-3.18.6 but note that this is only the initial cleanup, no fixes at this stage. Sincerely, Karl Palsson
