Messages in this thread | | | Date | Fri, 16 Oct 2015 10:39:13 -0500 | Subject | Re: [PATCH v2] USB: serial: cp210x: Workaround for cp2108 failure due to GET_LINE_CTL bug | From | Konstantin Shkolnyy <> |
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On Fri, Oct 16, 2015 at 10:27 AM, Johan Hovold <johan@kernel.org> wrote: > On Fri, Oct 16, 2015 at 10:11:12AM -0500, Konstantin Shkolnyy wrote: >> On Fri, Oct 16, 2015 at 8:27 AM, Johan Hovold <johan@kernel.org> wrote: >> > On Thu, Oct 15, 2015 at 06:23:31PM -0500, Konstantin Shkolnyy wrote: >> >> 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. >> > >> > That sounds weird. Are you saying that all or only some cp2108 devices >> > would be affected by this? And only for the line-control register? >> >> The bug exists in all current cp2108 devices and affects only >> GET_LINE_CTL. But it may be fixed in a future revision. > > Ok, have you some kind of confirmation from silabs on this already?
I work for SiLabs.
Thanks, Konstantin
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