Re: [PATCH v2 net-next] net: ethernet: ti: cpdma: correct error handling for chan create

[Grygorii Strashko]

On 12/12/2017 11:50 AM, Ivan Khoronzhuk wrote:
> On Tue, Dec 12, 2017 at 11:08:51AM -0600, Grygorii Strashko wrote:
> > On 12/12/2017 10:35 AM, Ivan Khoronzhuk wrote:
> > > It's not correct to return NULL when that is actually an error and
> > > function returns errors in any other wrong case. In the same time,
> > > the cpsw driver and davinci emac doesn't check error case while
> > > creating channel and it can miss actual error. Also remove WARNs
> > > duplicated dev_err msgs.
> > >
> > > Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@xxxxxxxxxx>
> > > ---
> > >    drivers/net/ethernet/ti/cpsw.c          | 12 +++++++++---
> > >    drivers/net/ethernet/ti/davinci_cpdma.c |  2 +-
> > >    drivers/net/ethernet/ti/davinci_emac.c  |  9 +++++++--
> > >    3 files changed, 17 insertions(+), 6 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/ti/cpsw.c b/drivers/net/ethernet/ti/cpsw.c
> > > index a60a378..3c85a08 100644
> > > --- a/drivers/net/ethernet/ti/cpsw.c
> > > +++ b/drivers/net/ethernet/ti/cpsw.c
> > > @@ -3065,10 +3065,16 @@ static int cpsw_probe(struct platform_device *pdev)
> > >    	}
> > >    
> > >    	cpsw->txv[0].ch = cpdma_chan_create(cpsw->dma, 0, cpsw_tx_handler, 0);
> > > +	if (IS_ERR(cpsw->txv[0].ch)) {
> > > +		dev_err(priv->dev, "error initializing tx dma channel\n");
> > > +		ret = PTR_ERR(cpsw->txv[0].ch);
> > > +		goto clean_dma_ret;
> > > +	}
> > > +
> > >    	cpsw->rxv[0].ch = cpdma_chan_create(cpsw->dma, 0, cpsw_rx_handler, 1);
> > > -	if (WARN_ON(!cpsw->rxv[0].ch || !cpsw->txv[0].ch)) {
> > > -		dev_err(priv->dev, "error initializing dma channels\n");
> > > -		ret = -ENOMEM;
> > > +	if (IS_ERR(cpsw->rxv[0].ch)) {
> > > +		dev_err(priv->dev, "error initializing rx dma channel\n");
> > > +		ret = PTR_ERR(cpsw->rxv[0].ch);
> > >    		goto clean_dma_ret;
> > >    	}
> > >    
> > > diff --git a/drivers/net/ethernet/ti/davinci_cpdma.c b/drivers/net/ethernet/ti/davinci_cpdma.c
> > > index e4d6edf..6f9173f 100644
> > > --- a/drivers/net/ethernet/ti/davinci_cpdma.c
> > > +++ b/drivers/net/ethernet/ti/davinci_cpdma.c
> > > @@ -893,7 +893,7 @@ struct cpdma_chan *cpdma_chan_create(struct cpdma_ctlr *ctlr, int chan_num,
> > >    	chan_num = rx_type ? rx_chan_num(chan_num) : tx_chan_num(chan_num);
> > >    
> > >    	if (__chan_linear(chan_num) >= ctlr->num_chan)
> > > -		return NULL;
> > > +		return ERR_PTR(-EINVAL);
> > >    
> > >    	chan = devm_kzalloc(ctlr->dev, sizeof(*chan), GFP_KERNEL);
> > >    	if (!chan)
> > > diff --git a/drivers/net/ethernet/ti/davinci_emac.c b/drivers/net/ethernet/ti/davinci_emac.c
> > > index f58c0c6..3d4af64 100644
> > > --- a/drivers/net/ethernet/ti/davinci_emac.c
> > > +++ b/drivers/net/ethernet/ti/davinci_emac.c
> > > @@ -1870,10 +1870,15 @@ static int davinci_emac_probe(struct platform_device *pdev)
> > >    
> > >    	priv->txchan = cpdma_chan_create(priv->dma, EMAC_DEF_TX_CH,
> > >    					 emac_tx_handler, 0);
> > > +	if (WARN_ON(IS_ERR(priv->txchan))) {
> >
> > So, logically WARN_ON() should be removed in  davinci_emac.c also. Right?
> It doesn't have dev_err() duplicate, so not very.
> But would be better to replace them on dev_err() if no objection.

right.

> > > +		rc = PTR_ERR(priv->txchan);
> > > +		goto no_cpdma_chan;
> > > +	}
> > > +
> > >    	priv->rxchan = cpdma_chan_create(priv->dma, EMAC_DEF_RX_CH,
> > >    					 emac_rx_handler, 1);
> > > -	if (WARN_ON(!priv->txchan || !priv->rxchan)) {
> > > -		rc = -ENOMEM;
> > > +	if (WARN_ON(IS_ERR(priv->rxchan))) {
> > > +		rc = PTR_ERR(priv->rxchan);
> > >    		goto no_cpdma_chan;
> > >    	}

--
regards,
-grygorii