Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1248901

Re: [PATCH v2] USB: serial: cp210x: Workaround for cp2108 failure due to GET_LINE_CTL bug

Show all headers | View raw

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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH v2] USB: serial: cp210x: Workaround for cp2108 failure due to GET_LINE_CTL bug Konstantin Shkolnyy <konstantin.shkolnyy@gmail.com> - 2015-10-16 01:30 +0200
  Re: [PATCH v2] USB: serial: cp210x: Workaround for cp2108 failure  due to GET_LINE_CTL bug Johan Hovold <johan@kernel.org> - 2015-10-16 15:30 +0200
    Re: [PATCH v2] USB: serial: cp210x: Workaround for cp2108 failure due  to GET_LINE_CTL bug Konstantin Shkolnyy <konstantin.shkolnyy@gmail.com> - 2015-10-16 17:20 +0200
      Re: [PATCH v2] USB: serial: cp210x: Workaround for cp2108 failure  due to GET_LINE_CTL bug Johan Hovold <johan@kernel.org> - 2015-10-16 17:30 +0200
        Re: [PATCH v2] USB: serial: cp210x: Workaround for cp2108 failure due  to GET_LINE_CTL bug Konstantin Shkolnyy <konstantin.shkolnyy@gmail.com> - 2015-10-16 17:40 +0200
          Re: [PATCH v2] USB: serial: cp210x: Workaround for cp2108 failure  due to GET_LINE_CTL bug Johan Hovold <johan@kernel.org> - 2015-10-16 17:50 +0200

csiph-web