Re: [PATCH RFC net-next v2 10/17] net: stmmac: Introduce internal PCS offset-based CSR access

Serge Semin
2024-07-03T18:03:49Z

On Fri, Jun 28, 2024 at 03:54:13PM +0100, Russell King (Oracle) wrote:
> On Mon, Jun 24, 2024 at 04:26:27PM +0300, Serge Semin wrote:
> > diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
> > index 80eb72bc6311..d0bcebe87ee8 100644
> > --- a/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
> > +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-qcom-ethqos.c
> > @@ -633,7 +633,7 @@ static int ethqos_configure_sgmii(struct qcom_ethqos *ethqos)
> > RGMII_CONFIG2_RGMII_CLK_SEL_CFG,
> > RGMII_IO_MACRO_CONFIG2);
> > ethqos_set_serdes_speed(ethqos, SPEED_2500);
> > - stmmac_pcs_ctrl_ane(priv, priv->ioaddr, 0, 0, 0);
> > + stmmac_pcs_ctrl_ane(priv, priv->pcsaddr, 0, 0, 0);
> > break;
> > case SPEED_1000:
> > val &= ~ETHQOS_MAC_CTRL_PORT_SEL;
> > @@ -641,12 +641,12 @@ static int ethqos_configure_sgmii(struct qcom_ethqos *ethqos)
> > RGMII_CONFIG2_RGMII_CLK_SEL_CFG,
> > RGMII_IO_MACRO_CONFIG2);
> > ethqos_set_serdes_speed(ethqos, SPEED_1000);
> > - stmmac_pcs_ctrl_ane(priv, priv->ioaddr, 1, 0, 0);
> > + stmmac_pcs_ctrl_ane(priv, priv->pcsaddr, 1, 0, 0);
> > break;
> > case SPEED_100:
> > val |= ETHQOS_MAC_CTRL_PORT_SEL | ETHQOS_MAC_CTRL_SPEED_MODE;
> > ethqos_set_serdes_speed(ethqos, SPEED_1000);
> > - stmmac_pcs_ctrl_ane(priv, priv->ioaddr, 1, 0, 0);
> > + stmmac_pcs_ctrl_ane(priv, priv->pcsaddr, 1, 0, 0);
> > break;
> > case SPEED_10:
> > val |= ETHQOS_MAC_CTRL_PORT_SEL;
> > @@ -656,7 +656,7 @@ static int ethqos_configure_sgmii(struct qcom_ethqos *ethqos)
> > SGMII_10M_RX_CLK_DVDR),
> > RGMII_IO_MACRO_CONFIG);
> > ethqos_set_serdes_speed(ethqos, SPEED_1000);
> > - stmmac_pcs_ctrl_ane(priv, priv->ioaddr, 1, 0, 0);
> > + stmmac_pcs_ctrl_ane(priv, priv->pcsaddr, 1, 0, 0);
> > break;
> > }
> >
>

> I think a better preparatory patch (given what you do in future patches)
> would be to change all of these to:
>
> ethqos_pcs_set_inband(priv, {false | true});
>
> which would be:
>
> static void ethqos_pcs_set_inband(struct stmmac_priv *priv, bool enable)
> {
> stmmac_pcs_ctrl_ane(priv, priv->ioaddr, enable, 0, 0);
> }
>
> which then means this patch becomes a single line, and your subsequent
> patch just has to replace stmmac_pcs_ctrl_ane() with its open-coded
> equivalent.

Why not. We can introduce one more preparation patch as you suggest.

>
> > diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.c b/drivers/net/ethernet/stmicro/stmmac/hwif.c
> > index 84fd57b76fad..3666893acb69 100644
> > --- a/drivers/net/ethernet/stmicro/stmmac/hwif.c
> > +++ b/drivers/net/ethernet/stmicro/stmmac/hwif.c
> > @@ -6,6 +6,7 @@
> >
> > #include "common.h"
> > #include "stmmac.h"
> > +#include "stmmac_pcs.h"
> > #include "stmmac_ptp.h"
> > #include "stmmac_est.h"
> >
> > @@ -116,6 +117,7 @@ static const struct stmmac_hwif_entry {
> > const void *tc;
> > const void *mmc;
> > const void *est;
> > + const void *pcs;
>

> I'm not a fan of void pointers. common.h includes linux/phylink.h, which
> will define struct phylink_pcs_ops, so there is no reason not to declare
> this as:
>
> const struct phylink_pcs_ops *pcs;

So am I. But in this case we have all the ops fields defined as voids.
So I just followed the local convention.

Anyway, I failed to find out the reason of using void pointers here.
So locally, in one of my cleanup patchesets, I've got them converted
to the typed pointers. I can submit that patch as another preparation
patch to this series. Then we can use the pointer to phylink_pcs_ops
with no doubts. What do you think?

-Serge(y)

>
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