Am 29.10.2013 10:07, schrieb Mika Westerberg: > On Mon, Oct 28, 2013 at 07:50:44PM +0100, Frank Schäfer wrote: >> Mika Westerberg has reported that the fixed+improved divisor based baud rate >> encoding method doesn't work anymore with his HXD device. >> So until we've found out what's going on, reintroduce the old encoding algorithm >> and use it for this and all newer chips for baud rates > 115200 baud. >> Also switch back to the direct encoding method for baud rates <= 115200, because >> it's unclear if the old divisor based encoding algorithm works for them. >> >> Reported-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx> >> Signed-off-by: Frank Schäfer <fschaefer.oss@xxxxxxxxxxxxxx> > Tried this and with 115200 it works and fixes the problem. However, with > speeds like 230400 and 460800 it still corrupts data. Well, with this patch we go back to what we did since kernel 3.1 (since commit 8d48fdf689fe "USB: PL2303: correctly handle baudrates above 115200"), so you should face the same problems with these kernels, too. Please note that there are serious doubts with regards to the baud rate precision of this algorithm and if it has really ever been working with all chips. The commit description doesn't say where it comes from (likey based on reverse-enginnering) and which chips it tries to fix. :( We've contacted the author, but got no reply. With HX chips, it only worked "more or less" for baud rates ~115200 to ~500000 and but the actual baud rate always differed a little. With commit 57ce61aad748 we fixed/improved this algorithm, but apparently this doesn't work for HXD chips (which is a bit surprising). I hope I'll get one of these devices at the end of this week. > I also got few whitespace warnings when applied this using 'git am'. Ick, thanks. Will send a fixed version. Regards, Frank -- 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
