Re: [net-next v2 2/9] net: stmmac: platform: Convert to devm_clk_get_enabled() and devm_clk_get_optional_enabled()

Serge Semin
2024-08-23T09:37:24Z

Hi Biju

On Fri, Aug 23, 2024 at 09:15:06AM +0000, Biju Das wrote:
> Hi Serge Semin,
>
> > -----Original Message-----
> > From: Serge Semin <fancer.lancer@gmail.com>
> > Sent: Friday, August 23, 2024 10:11 AM
> > Subject: Re: [net-next v2 2/9] net: stmmac: platform: Convert to devm_clk_get_enabled() and
> > devm_clk_get_optional_enabled()
> >
> > Hi Yangtao
> >
> > On Fri, Aug 23, 2024 at 01:21:14AM -0600, Yangtao Li wrote:
> > > Use devm_clk_get_enabled() and devm_clk_get_optional_enabled() to
> > > simplify code.
> > >
> > > Signed-off-by: Yangtao Li <frank.li@vivo.com>
> > > Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
> > > ---
> > > v2:
> > > -remove unused 'ret'
> > > -fix incompatible-pointer-types
> > >
> > > .../ethernet/stmicro/stmmac/stmmac_platform.c | 35
> > > +++++--------------
> > > 1 file changed, 8 insertions(+), 27 deletions(-)
> > >
> > > diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > > b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > > index ad868e8d195d..1a66baaa4081 100644
> > > --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > > +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
> > > @@ -415,8 +415,6 @@ static int stmmac_of_get_mac_mode(struct
> > > device_node *np) static void stmmac_remove_config_dt(struct platform_device *pdev,
> > > struct plat_stmmacenet_data *plat) {
> > > - clk_disable_unprepare(plat->stmmac_clk);
> > > - clk_disable_unprepare(plat->pclk);
> > > of_node_put(plat->phy_node);
> > > of_node_put(plat->mdio_node);
> > > }
> > > @@ -436,7 +434,6 @@ stmmac_probe_config_dt(struct platform_device *pdev, u8 *mac)
> > > struct plat_stmmacenet_data *plat;
> > > struct stmmac_dma_cfg *dma_cfg;
> > > int phy_mode;
> > > - void *ret;
> > > int rc;
> > >
> > > plat = devm_kzalloc(&pdev->dev, sizeof(*plat), GFP_KERNEL); @@
> > > -615,21 +612,16 @@ stmmac_probe_config_dt(struct platform_device
> > > *pdev, u8 *mac)
> > >
> > > /* clock setup */
> > > if (!of_device_is_compatible(np, "snps,dwc-qos-ethernet-4.10")) {
> > > - plat->stmmac_clk = devm_clk_get(&pdev->dev,
> > > - STMMAC_RESOURCE_NAME);
> > > + plat->stmmac_clk = devm_clk_get_enabled(&pdev->dev,
> > > +STMMAC_RESOURCE_NAME);
> > > if (IS_ERR(plat->stmmac_clk)) {
> > > dev_warn(&pdev->dev, "Cannot get CSR clock\n");
> > > plat->stmmac_clk = NULL;
> > > }
> > > - clk_prepare_enable(plat->stmmac_clk);
> > > }
> > >
> > > - plat->pclk = devm_clk_get_optional(&pdev->dev, "pclk");
> > > - if (IS_ERR(plat->pclk)) {
> > > - ret = plat->pclk;
> > > - goto error_pclk_get;
> > > - }
> > > - clk_prepare_enable(plat->pclk);
> > > + plat->pclk = devm_clk_get_optional_enabled(&pdev->dev, "pclk");
> > > + if (IS_ERR(plat->pclk))
> >
> > > + return (void *)plat->pclk;
> >
> > Use the ERR_CAST() macro instead of the open coded void type cast.
>

> Which is better ERR_PTR or ERR_CAST in this case?

The only correct macro in this case is ERR_CAST() which implies one
error-pointer cast to another. Open-coding the pointers cast is
discouraged.

The ERR_PTR() macro is utilized to cast an _integer-error_ to an
error-pointer.

-Serge(y)

>
> Cheers,
> Biju
>
> >
> > >
> > > /* Fall-back to main clock in case of no PTP ref is passed */
> > > plat->clk_ptp_ref = devm_clk_get(&pdev->dev, "ptp_ref"); @@ -644,26
> > > +636,15 @@ stmmac_probe_config_dt(struct platform_device *pdev, u8
> > > *mac)
> > >
> > > plat->stmmac_rst = devm_reset_control_get_optional(&pdev->dev,
> > > STMMAC_RESOURCE_NAME);
> > > - if (IS_ERR(plat->stmmac_rst)) {
> > > - ret = plat->stmmac_rst;
> > > - goto error_hw_init;
> > > - }
> > > + if (IS_ERR(plat->stmmac_rst))
> >
> > > + return (void *)plat->stmmac_rst;
> >
> > ditto
> >
> > >
> > > plat->stmmac_ahb_rst = devm_reset_control_get_optional_shared(
> > > &pdev->dev, "ahb");
> > > - if (IS_ERR(plat->stmmac_ahb_rst)) {
> > > - ret = plat->stmmac_ahb_rst;
> > > - goto error_hw_init;
> > > - }
> > > + if (IS_ERR(plat->stmmac_ahb_rst))
> >
> > > + return (void *)plat->stmmac_ahb_rst;
> >
> > ditto
> >
> > -Serge(y)
> >
> > >
> > > return plat;
> > > -
> > > -error_hw_init:
> > > - clk_disable_unprepare(plat->pclk);
> > > -error_pclk_get:
> > > - clk_disable_unprepare(plat->stmmac_clk);
> > > -
> > > - return ret;
> > > }
> > >
> > > static void devm_stmmac_remove_config_dt(void *data)
> > > --
> > > 2.39.0
> > >
> > >
>