Messages in this thread | | | Date | Thu, 31 Mar 2011 13:11:44 +0100 | From | Alan Cox <> | Subject | Re: [PATCH] tty/n_gsm: fix bug in CRC calculation for gsm1 mode |
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On Sun, 27 Mar 2011 04:05:00 +0400 Mikhail Kshevetskiy <mikhail.kshevetskiy@gmail.com> wrote:
> Problem description: > gsm_queue() calculate a CRC for arrived frames. As a last step of > CRC calculation it call > > gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->received_fcs); > > This work perfectly for the case of GSM0 mode as gsm->received_fcs > contain the last piece of data required to generate final CRC. > > gsm->received_fcs is not used for GSM1 mode. Thus we put an > additional byte to CRC calculation. As result we get a wrong CRC > and reject incoming frame. > > Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@gmail.com>
Acked-by: Alan Cox <alan@linux.intel.com>
(This wants cleaning up better as Mikhael also says but this patch is clear and unlike a big clean up a better base point for a stable fix and can be reworked further)
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