On Mon, Dec 12, 2016 at 10:19 AM, Johan Hovold <johan@xxxxxxxxxx> wrote: > On Mon, Dec 12, 2016 at 08:03:03AM -0800, Russell Senior wrote: >> On Mon, Dec 12, 2016 at 7:54 AM, Johan Hovold <johan@xxxxxxxxxx> wrote: >> > On Mon, Dec 12, 2016 at 07:51:59AM -0800, Russell Senior wrote: >> >> On Mon, Dec 12, 2016 at 7:40 AM, Johan Hovold <johan@xxxxxxxxxx> wrote: >> >> > On Mon, Dec 12, 2016 at 07:09:34AM -0800, Russell Senior wrote: >> >> >> On Mon, Dec 12, 2016 at 1:54 AM, Johan Hovold <johan@xxxxxxxxxx> wrote: >> >> >> >> >> >> > Ok, so maybe your device simply does not support changing the line >> >> >> > settings more than once. That is, the initial settings chosen are used >> >> >> > until re-connected. This would seem to be in accordance with a comment >> >> >> > found in one of the out-of-tree drivers floating around (and which at >> >> >> > least I hoped would no longer be an issue with the new way of changing >> >> >> > the settings). >> >> >> > >> >> >> > If you connect the ch340 you have in loopback mode, with the removed >> >> >> > initial LCR write that fixed the 5-bit behaviour, can you get that >> >> >> > behaviour back by setting 5-bit word size after opening the port? (This >> >> >> > was what I was going for with my original question above.). >> >> >> >> >> >> With minicom configured with 5N1 (that is, 5-bit mode), loopback looks >> >> >> normal. I type an 'a' and I get and 'a' back. Likewise, I type an >> >> >> 'A' and I get an 'A' back. I used a saved .minicom.dfl file to >> >> >> configure the port. >> >> > >> >> > Ok, so that seems to confirm the suspicion that changing settings after >> >> > the initial configuration is failing (even though the device does indeed >> >> > support 5-bit mode). >> >> > >> >> > Could you try to verify if that applies to the baud rate as well? That >> >> > is, can you switch between say 9600 and 115200 after opening the port >> >> > and verify that against the pl2303? >> >> > >> >> > Still using usb-linus with the first LCR write removed. >> >> >> >> I can change the baud rate on the ch341 and make it not work with the >> >> pl2303 (e.g. I send an 'A' from the pl2030 and get an 0xff on the >> >> ch341, and vice versa), then harmonize the baud rate again and it >> >> works again. Changing baud rate seems to work. >> > >> > That's good. And just to confirm: you managed to get characters through >> > at both rates? >> >> Yes, indeed. >> >> When the baud rates match (tested 9600 and 115200), characters arrive >> as expected in both directions. > > Can you try also the below diagnostics patch on top of usb-next (not > usb-linus this time)? > > It seems we should be able to revert to setting the divisors and lcr > directly for all CH340 devices, while using the new method for CH341 > only (which requires it). > > Just want to make sure that keeping a common init sequence would still > work first. > > Note that I don't expect you to be able to change word size, but > hopefully a default 8N1 will work while the baud rate would be > configurable. If both sides (ch341 and pl2303) are configured 8N1, your new patch works. When both sides are configured for the same baud rate, it works. Changing ch341 to a different baud rate from the pl2303 is stops working, which implies that baud rate changes are working. -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
