On Mon, Oct 19, 2015 at 05:01:40PM -0500, Konstantin Shkolnyy wrote: > This patch can only be applied after the patch titled > "USB: serial: cp210x: Implement 16-bit register access functions" No need to put this in the commit message, ordering is assumed to be correct when you submit a series of patches. > Work around 2 cp2108 bugs: > > 1) cp2108 GET_LINE_CTL returns the 16-bit value with the 2 bytes swapped. > However, SET_LINE_CTL functions properly. When the driver tries to modify > the register, it reads it, modifies some bits and writes back. Because > the read bytes were swapped, this often results in an invalid value to be > written. In turn, this causes cp2108 respond with a stall. The stall > sometimes doesn't clear properly and cp2108 starts responding to following > valid commands also with stalls, effectively failing. > > 2) Occasionally, writing data and immediately closing the port makes cp2108 > stop responding. The device had to be unplugged to clear the error. > The failure is induced by shutting down the device while its Tx queue still > has unsent data. This condition is avoided by issuing PURGE command from > the close() callback. Two distinct fixes need to go in separate patches. You should end up with something like the following series - fix hang after close (purge) - refactor lcr handling - fix cp2108 lcr handling - more clean ups... Thanks, Johan -- 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
