Re: [PATCH net-next v2 0/3] Followup fixes for the dwmac and altera lynx conversion

From: Russell King (Oracle)
Date: Tue Jun 06 2023 - 10:33:25 EST


On Tue, Jun 06, 2023 at 04:21:41PM +0200, Maxime Chevallier wrote:
> Following the TSE PCS removal and port of altera_tse and dwmac_socfpga,
> this series fixes some issues that slipped through the cracks.
>
> Patch 1 fixes an unitialized struct in altera_tse
>
> Patch 2 uses the correct Kconfig option for altera_tse
>
> Patch 3 makes the Lynx PCS specific to dwmac_socfpga. This patch was
> originally written by Russell, my modifications just moves the
> #include<linux/pcs-lynx.h> around, to use it only in dwmac_socfpga.

Hi Maxime,

I'm sorry, but I think you need an extra patch added to this series.
Looking at include/linux/mdio/mdio-regmap.h, that defines:

struct mdio_regmap_config {
struct device *parent;
struct regmap *regmap;
char name[MII_BUS_ID_SIZE];
u8 valid_addr;
bool autoscan;
};

In dwmac-socfpga.c, you have:

struct mdio_regmap_config mrc;

mrc.regmap = pcs_regmap;
mrc.parent = &pdev->dev;
mrc.valid_addr = 0x0;

snprintf(mrc.name, MII_BUS_ID_SIZE, "%s-pcs-mii", ndev->name);

So that's a tick for parent, tick for regmap, tick for name, tick
for valid_addr, but... autoscan is left uninitialised.
devm_mdio_regmap_register() reads this, and uses it to decide
how to set mii->phy_mask, which will be randomly ~0 or ~BIT(0)
depending on the value of mrc.autoscan.

Other than that, the series looks good. Thanks.

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