Re: [PATCH V2 2/3] soc: ti: knav_dma: Make knav_dma_open_channel return NULL on error

[Nishanth Menon <nm@ti.com>]

On 16:59-20250930, Jacob Keller wrote:
> 
> 
> On 9/30/2025 5:16 AM, Nishanth Menon wrote:
> > Make knav_dma_open_channel consistently return NULL on error instead of
> > ERR_PTR. Currently the header include/linux/soc/ti/knav_dma.h returns NUL
> > when the driver is disabled, but the driver implementation returns
> > ERR_PTR(-EINVAL), creating API inconsistency for users.
> > 
> 
> I would word this as indicating that we don't even use ERR_PTR here at all!

Thanks. Yep, will do for the next respin.

> 
> > Standardize the error handling by making the function return NULL on all
> > error conditions.
> > 
> > Suggested-by: Simon Horman <horms@kernel.org>
> > Signed-off-by: Nishanth Menon <nm@ti.com>
> > ---
> > Changes in V2:
> > * renewed version
> > 
> >  drivers/soc/ti/knav_dma.c | 14 +++++++-------
> >  1 file changed, 7 insertions(+), 7 deletions(-)
> > 
> > diff --git a/drivers/soc/ti/knav_dma.c b/drivers/soc/ti/knav_dma.c
> > index a25ebe6cd503..e69f0946de29 100644
> > --- a/drivers/soc/ti/knav_dma.c
> > +++ b/drivers/soc/ti/knav_dma.c
> > @@ -402,7 +402,7 @@ static int of_channel_match_helper(struct device_node *np, const char *name,
> >   * @name:	slave channel name
> >   * @config:	dma configuration parameters
> >   *
> > - * Returns pointer to appropriate DMA channel on success or error.
> > + * Returns pointer to appropriate DMA channel on success or NULL on error.
> >   */
> >  void *knav_dma_open_channel(struct device *dev, const char *name,
> >  					struct knav_dma_cfg *config)
> > @@ -414,13 +414,13 @@ void *knav_dma_open_channel(struct device *dev, const char *name,
> >  
> >  	if (!kdev) {
> >  		pr_err("keystone-navigator-dma driver not registered\n");
> > -		return (void *)-EINVAL;
> > +		return NULL;
> 
> Wow. The driver doesn't even return ERR_PTR, but just directly casts
> -EINVAL to a void *... thats quite ugly. Good to remove this.
> 




-- 
Regards,
Nishanth Menon
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