On Sun, 27 Mar 2011 14:30:24 +0100 Alan Cox <[email protected]> wrote:
> > 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. > > That much is true except that it was originally tested with gsm encoding > 1 on various modems for a while and not seen the problem. So I am trying > to work out why or whether some of the GSM0 patches broke GSM1 somewhere. as i can see, it's your commit c2f2f0000bb69f067fea12624272e6a58a811702. Why we need received_fcs variable? We can completely drop it and calculate fsc in gsm0_receive() and gsm1_receive(). gsm_queue() in this case will contain only fsc checking code. > What hardware was it tested on ? Enfora, Inc. Enabler-III G Modem > It looks right - probably the code wants pushing into > gsm0_receive/gsm1_receive appropriately so no special cases leak into > gsm_queue. It's possible, see my comment about received_fcs variable above > > > > > > Signed-off-by: Mikhail Kshevetskiy <[email protected]> > > --- > > drivers/tty/n_gsm.c | 8 ++++++-- > > 1 files changed, 6 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c > > index 176f632..4806276 100644 > > --- a/drivers/tty/n_gsm.c > > +++ b/drivers/tty/n_gsm.c > > @@ -1658,8 +1658,12 @@ static void gsm_queue(struct gsm_mux *gsm) > > > > if ((gsm->control & ~PF) == UI) > > gsm->fcs = gsm_fcs_add_block(gsm->fcs, gsm->buf, gsm->len); > > - /* generate final CRC with received FCS */ > > - gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->received_fcs); > > + if (gsm->encoding == 0){ > > + /* WARNING: gsm->received_fcs is used for gsm->encoding = 0 > > only. > > + In this case it contain the last piece of data > > + required to generate final CRC */ > > + gsm->fcs = gsm_fcs_add(gsm->fcs, gsm->received_fcs); > > + } > > if (gsm->fcs != GOOD_FCS) { > > gsm->bad_fcs++; > > if (debug & 4) > > > -- > -- > "Alan, I'm getting a bit worried about you." > -- Linus Torvalds _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
