Re: [PATCH 09/24] staging: wilc1000: move static variable clients_count to 'wilc' structure

[Adham Abozaeid <adham.abozaeid@microchip.com>]

On Thu, 23 Aug 2018 11:09:56 +0300
Claudiu Beznea <Claudiu.Beznea@microchip.com> wrote:

> 
> 
> On 14.08.2018 09:50, Ajay Singh wrote:
> > Avoid use of static variable 'clients_count' and move it part of 'wilc'
> > structure.
> > 
> > Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
> > ---
> >  drivers/staging/wilc1000/host_interface.c     | 9 ++++-----
> >  drivers/staging/wilc1000/wilc_wfi_netdevice.h | 1 +
> >  2 files changed, 5 insertions(+), 5 deletions(-)
> > 
> > diff --git a/drivers/staging/wilc1000/host_interface.c b/drivers/staging/wilc1000/host_interface.c
> > index 6225e67..d930f06 100644
> > --- a/drivers/staging/wilc1000/host_interface.c
> > +++ b/drivers/staging/wilc1000/host_interface.c
> > @@ -199,7 +199,6 @@ static u8 rcv_assoc_resp[MAX_ASSOC_RESP_FRAME_SIZE];
> >  
> >  static u8 set_ip[2][4];
> >  static u8 get_ip[2][4];
> > -static u32 clients_count;
> >  
> >  static int host_int_get_ipaddress(struct wilc_vif *vif, u8 *ip_addr, u8 idx);
> >  
> > @@ -3456,7 +3455,7 @@ int wilc_init(struct net_device *dev, struct host_if_drv **hif_drv_handler)
> >  
> >  	vif->obtaining_ip = false;
> >  
> > -	if (clients_count == 0) {
> > +	if (wilc->clients_count == 0) {
> 
> The check of this should be mutex protected or a hif init/deinit should be
> done in probe/remove code not not in open (I'm for the second approach).
> Imagine this scenario:
> 
> vif 1: is down
> vif 2: is down. "ifconfig vif2 up" is executed and the execution reach this
>        point and then suspends after "if (wilc->clients_count == 0)" check
> vif 1: "ifconfig vif1 up" and execution reach the end of this function and
>        then the execution for vif 2 resumes. This will init twice the hif
>        mutex, completion etc.
> 
> >  		init_completion(&hif_driver_comp);
> >  		mutex_init(&hif_deinit_lock);
> >  

Instead of using mutex protection, it would be better to move this block to
wilc_netdev_init() where wilc structure is initialized 

> > @@ -3490,7 +3489,7 @@ int wilc_init(struct net_device *dev, struct host_if_drv **hif_drv_handler)
> >  
> >  	mutex_unlock(&hif_drv->cfg_values_lock);
> >  
> > -	clients_count++;
> > +	wilc->clients_count++;
> >  
> >  	return 0;
> >  }
> > @@ -3526,7 +3525,7 @@ int wilc_deinit(struct wilc_vif *vif)
> >  
> >  	hif_drv->hif_state = HOST_IF_IDLE;
> >  
> > -	if (clients_count == 1)	{
> > +	if (vif->wilc->clients_count == 1) {
> >  		struct host_if_msg *msg;
> >  
> >  		msg = wilc_alloc_work(vif, handle_hif_exit_work, true);
> > @@ -3544,7 +3543,7 @@ int wilc_deinit(struct wilc_vif *vif)
> >  
> >  	kfree(hif_drv);
> >  
> > -	clients_count--;
> > +	vif->wilc->clients_count--;
> >  	terminated_handle = NULL;
> >  	mutex_unlock(&hif_deinit_lock);
> >  	return result;
> > diff --git a/drivers/staging/wilc1000/wilc_wfi_netdevice.h b/drivers/staging/wilc1000/wilc_wfi_netdevice.h
> > index 8e56a28..8cccbbc 100644
> > --- a/drivers/staging/wilc1000/wilc_wfi_netdevice.h
> > +++ b/drivers/staging/wilc1000/wilc_wfi_netdevice.h
> > @@ -171,6 +171,7 @@ struct wilc {
> >  
> >  	struct rf_info dummy_statistics;
> >  	bool enable_ps;
> > +	int clients_count;
> >  };
> >  
> >  struct wilc_wfi_mon_priv {
> >