On Thu, Aug 17, 2023 at 11:32:23AM +0200, D. Starke wrote: > From: Daniel Starke <daniel.starke@xxxxxxxxxxx> > > Currently, changing the parameters of a DLCI gives no direct control to the > user whether this should trigger a channel reset or not. The decision is > solely made by the driver based on the assumption which parameter changes > are compatible or not. Therefore, the user has no means to perform an > automatic channel reset after parameter configuration for non-conflicting > changes. > > Add the parameter 'flags' to 'gsm_dlci_config' to force a channel reset > after ioctl setting regardless of whether the changes made require this or > not by setting this to 'GSM_FL_RESTART'. > > Note that 'GSM_FL_RESTART' is currently the only allow flag to allow > additions here. > > Signed-off-by: Daniel Starke <daniel.starke@xxxxxxxxxxx> > --- > drivers/tty/n_gsm.c | 4 ++++ > include/uapi/linux/gsmmux.h | 15 ++++++++++++++- > 2 files changed, 18 insertions(+), 1 deletion(-) > > v5 -> v6: > No changes. > > Link: https://lore.kernel.org/all/20230517155704.5701-1-daniel.starke@xxxxxxxxxxx/ > > diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c > index 42759500b79e..a4268515920e 100644 > --- a/drivers/tty/n_gsm.c > +++ b/drivers/tty/n_gsm.c > @@ -2532,6 +2532,8 @@ static int gsm_dlci_config(struct gsm_dlci *dlci, struct gsm_dlci_config *dc, in > return -EINVAL; > if (dc->k > 7) > return -EINVAL; > + if (dc->flags & ~GSM_FL_RESTART) /* allow future extensions */ > + return -EINVAL; > > /* > * See what is needed for reconfiguration > @@ -2546,6 +2548,8 @@ static int gsm_dlci_config(struct gsm_dlci *dlci, struct gsm_dlci_config *dc, in > /* Requires care */ > if (dc->priority != dlci->prio) > need_restart = true; > + if (dc->flags & GSM_FL_RESTART) > + need_restart = true; > > if ((open && gsm->wait_config) || need_restart) > need_open = true; > diff --git a/include/uapi/linux/gsmmux.h b/include/uapi/linux/gsmmux.h > index eb67884e5f38..e56e2d7ea6eb 100644 > --- a/include/uapi/linux/gsmmux.h > +++ b/include/uapi/linux/gsmmux.h > @@ -2,10 +2,22 @@ > #ifndef _LINUX_GSMMUX_H > #define _LINUX_GSMMUX_H > > +#include <linux/const.h> > #include <linux/if.h> > #include <linux/ioctl.h> > #include <linux/types.h> > > +/* > + * flags definition for n_gsm > + * > + * Used by: > + * struct gsm_dlci_config.flags > + */ > +/* Forces a DLCI reset if set. Otherwise, a DLCI reset is only done if > + * incompatible settings were provided. Always cleared on retrieval. > + */ > +#define GSM_FL_RESTART _BITUL(0) > + > struct gsm_config > { > unsigned int adaption; > @@ -58,7 +70,8 @@ struct gsm_dlci_config { > __u32 priority; /* Priority (0 for default value) */ > __u32 i; /* Frame type (1 = UIH, 2 = UI) */ > __u32 k; /* Window size (0 for default value) */ > - __u32 reserved[8]; /* For future use, must be initialized to zero */ > + __u32 flags; /* DLCI specific flags. */ This should be called "dlci_flags" right? Otherwise when you add more flags in the reserved area, what will you call them? thanks, greg k-h
