Re: [PATCH v3 4/6] staging: r8188eu: add error handling of rtw_read16

[Pavel Skripkin <paskripkin@xxxxxxxxx>]

On 8/26/21 1:50 PM, Greg KH wrote:
> On Tue, Aug 24, 2021 at 10:27:35AM +0300, Pavel Skripkin wrote:
> > _rtw_read16 function can fail in case of usb transfer failure. But
> > previous function prototype wasn't designed to return an error to
> > caller. It can cause a lot uninit value bugs all across the driver code,
> > since rtw_read16() returns local stack variable to caller.
> >
> > Fix it by changing the prototype of this function. Now it returns an
> > int: 0 on success, negative error value on failure and callers should pass
> > the pointer to storage location for register value.
> >
> > Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx>
> > ---
> >  drivers/staging/r8188eu/core/rtw_debug.c      |  7 +++-
> >  drivers/staging/r8188eu/core/rtw_io.c         |  9 ++---
> >  drivers/staging/r8188eu/core/rtw_mp_ioctl.c   |  4 +-
> >  drivers/staging/r8188eu/hal/odm_interface.c   |  4 +-
> >  .../staging/r8188eu/hal/rtl8188e_hal_init.c   | 29 +++++++++++----
> >  drivers/staging/r8188eu/hal/rtl8188e_phycfg.c |  5 ++-
> >  drivers/staging/r8188eu/hal/usb_halinit.c     | 37 ++++++++++++++++---
> >  drivers/staging/r8188eu/hal/usb_ops_linux.c   | 22 +++++++++--
> >  .../staging/r8188eu/include/odm_interface.h   |  2 +-
> >  drivers/staging/r8188eu/include/rtw_io.h      |  6 +--
> >  drivers/staging/r8188eu/os_dep/ioctl_linux.c  | 28 +++++++++++---
> >  11 files changed, 115 insertions(+), 38 deletions(-)
> >
> > diff --git a/drivers/staging/r8188eu/core/rtw_debug.c b/drivers/staging/r8188eu/core/rtw_debug.c
> > index 8b7d3eb12bd0..a41675e101ac 100644
> > --- a/drivers/staging/r8188eu/core/rtw_debug.c
> > +++ b/drivers/staging/r8188eu/core/rtw_debug.c
> > @@ -91,7 +91,12 @@ int proc_get_read_reg(char *page, char **start,
> >  				proc_get_read_addr, (u8) tmp);
> >  		break;
> >  	case 2:
> > -		len += snprintf(page + len, count - len, "rtw_read16(0x%x)=0x%x\n", proc_get_read_addr, rtw_read16(padapter, proc_get_read_addr));
> > +		error = rtw_read16(padapter, proc_get_read_addr, (u16 *) &tmp);
> > +		if (error)
> > +			return len;
> > +
> > +		len += snprintf(page + len, count - len, "rtw_read16(0x%x)=0x%x\n",
> > +				proc_get_read_addr, (u16) tmp);
> >  		break;
> >  	case 4:
> >  		len += snprintf(page + len, count - len, "rtw_read32(0x%x)=0x%x\n", proc_get_read_addr, rtw_read32(padapter, proc_get_read_addr));
> > diff --git a/drivers/staging/r8188eu/core/rtw_io.c b/drivers/staging/r8188eu/core/rtw_io.c
> > index 2714506c8ffb..fd64893c778d 100644
> > --- a/drivers/staging/r8188eu/core/rtw_io.c
> > +++ b/drivers/staging/r8188eu/core/rtw_io.c
> > @@ -45,18 +45,15 @@ int __must_check _rtw_read8(struct adapter *adapter, u32 addr, u8 *data)
> >  	return _read8(pintfhdl, addr, data);
> >  }
> >  
> > -u16 _rtw_read16(struct adapter *adapter, u32 addr)
> > +int __must_check _rtw_read16(struct adapter *adapter, u32 addr, u16 *data)
> >  {
> > -	u16 r_val;
> >  	struct io_priv *pio_priv = &adapter->iopriv;
> >  	struct	intf_hdl		*pintfhdl = &pio_priv->intf;
> > -	u16 (*_read16)(struct intf_hdl *pintfhdl, u32 addr);
> > +	int (*_read16)(struct intf_hdl *pintfhdl, u32 addr, u16 *data);
> >  
> >  	_read16 = pintfhdl->io_ops._read16;
>
> Why do you need this extra pointer abstraction anyway?  Please unwind
> that first, which will make this function go away (or get easier to
> understand at the least...)
It was there before my changes :) I had a plan to clean up DBG macros 
and this abstraction after adding error handling...


If you feel, that these clean up are needed before error handling, I can 
add them to this series :) Anyway, some of them are already in my local 
tree



With regards,
Pavel Skripkin