netdev - Re: [PATCH net-next v9 11/13] net: phy: add driver for built-in 2.5G ethernet PHY on MT7988

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Date: Thu, 27 Jun 2024 08:19:30 +0000
From: SkyLake Huang (黃啟澤)
	<SkyLake.Huang@...iatek.com>
To: "horms@...nel.org" <horms@...nel.org>
CC: "andrew@...n.ch" <andrew@...n.ch>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>, "linux-mediatek@...ts.infradead.org"
	<linux-mediatek@...ts.infradead.org>, "linux-arm-kernel@...ts.infradead.org"
	<linux-arm-kernel@...ts.infradead.org>, "linux@...linux.org.uk"
	<linux@...linux.org.uk>, "kuba@...nel.org" <kuba@...nel.org>,
	"pabeni@...hat.com" <pabeni@...hat.com>, "edumazet@...gle.com"
	<edumazet@...gle.com>, "netdev@...r.kernel.org" <netdev@...r.kernel.org>,
	"dqfext@...il.com" <dqfext@...il.com>,
	Steven Liu (劉人豪) <steven.liu@...iatek.com>,
	"matthias.bgg@...il.com" <matthias.bgg@...il.com>, "davem@...emloft.net"
	<davem@...emloft.net>, "hkallweit1@...il.com" <hkallweit1@...il.com>,
	"daniel@...rotopia.org" <daniel@...rotopia.org>,
	"angelogioacchino.delregno@...labora.com"
	<angelogioacchino.delregno@...labora.com>
Subject: Re: [PATCH net-next v9 11/13] net: phy: add driver for built-in 2.5G
 ethernet PHY on MT7988

On Wed, 2024-06-26 at 19:52 +0100, Simon Horman wrote:
>  	 
> External email : Please do not click links or open attachments until
> you have verified the sender or the content.
>  On Wed, Jun 26, 2024 at 06:43:27PM +0800, Sky Huang wrote:
> > From: "SkyLake.Huang" <skylake.huang@...iatek.com>
> > 
> > Add support for internal 2.5Gphy on MT7988. This driver will load
> > necessary firmware, add appropriate time delay and figure out LED.
> > Also, certain control registers will be set to fix link-up issues.
> > 
> > Signed-off-by: SkyLake.Huang <skylake.huang@...iatek.com>
> 
> ...
> 
> Hi Sky,
> 
> Sorry for not providing this review earlier in the process.
> 
It's ok.

> > diff --git a/drivers/net/phy/mediatek/mtk-2p5ge.c
> b/drivers/net/phy/mediatek/mtk-2p5ge.c
> 
> ...
> 
> > +static int mt798x_2p5ge_phy_load_fw(struct phy_device *phydev)
> > +{
> > +struct mtk_i2p5ge_phy_priv *priv = phydev->priv;
> > +void __iomem *md32_en_cfg_base, *pmb_addr;
> > +struct device *dev = &phydev->mdio.dev;
> > +const struct firmware *fw;
> > +int ret, i;
> > +u16 reg;
> > +
> > +if (priv->fw_loaded)
> > +return 0;
> > +
> > +pmb_addr = ioremap(MT7988_2P5GE_PMB_FW_BASE,
> MT7988_2P5GE_PMB_FW_LEN);
> > +if (!pmb_addr)
> > +return -ENOMEM;
> > +md32_en_cfg_base = ioremap(MT7988_2P5GE_MD32_EN_CFG_BASE,
> > +   MT7988_2P5GE_MD32_EN_CFG_LEN);
> > +if (!md32_en_cfg_base) {
> > +ret = -ENOMEM;
> > +goto free_pmb;
> > +}
> > +
> > +ret = request_firmware(&fw, MT7988_2P5GE_PMB_FW, dev);
> > +if (ret) {
> > +dev_err(dev, "failed to load firmware: %s, ret: %d\n",
> > +MT7988_2P5GE_PMB_FW, ret);
> > +goto free;
> > +}
> > +
> > +if (fw->size != MT7988_2P5GE_PMB_FW_SIZE) {
> > +dev_err(dev, "Firmware size 0x%zx != 0x%x\n",
> > +fw->size, MT7988_2P5GE_PMB_FW_SIZE);
> > +ret = -EINVAL;
> > +goto free;
> 
> It seems that this leaks any resources allocated by
> request_firmware():
> I think a call to release_firmware() is needed in this unwind path.
> 
> Flagged by Smatch.
> 
Please see the fix down below.

> > +}
> > +
> > +reg = readw(md32_en_cfg_base);
> > +if (reg & MD32_EN) {
> > +phy_set_bits(phydev, MII_BMCR, BMCR_RESET);
> > +usleep_range(10000, 11000);
> > +}
> > +phy_set_bits(phydev, MII_BMCR, BMCR_PDOWN);
> > +
> > +/* Write magic number to safely stall MCU */
> > +phy_write_mmd(phydev, MDIO_MMD_VEND1, 0x800e, 0x1100);
> > +phy_write_mmd(phydev, MDIO_MMD_VEND1, 0x800f, 0x00df);
> > +
> > +for (i = 0; i < MT7988_2P5GE_PMB_FW_SIZE - 1; i += 4)
> > +writel(*((uint32_t *)(fw->data + i)), pmb_addr + i);
> > +release_firmware(fw);
> > +dev_info(dev, "Firmware date code: %x/%x/%x, version: %x.%x\n",
> > + be16_to_cpu(*((__be16 *)(fw->data +
> > +  MT7988_2P5GE_PMB_FW_SIZE - 8))),
> > + *(fw->data + MT7988_2P5GE_PMB_FW_SIZE - 6),
> > + *(fw->data + MT7988_2P5GE_PMB_FW_SIZE - 5),
> > + *(fw->data + MT7988_2P5GE_PMB_FW_SIZE - 2),
> > + *(fw->data + MT7988_2P5GE_PMB_FW_SIZE - 1));
> > +
> > +writew(reg & ~MD32_EN, md32_en_cfg_base);
> > +writew(reg | MD32_EN, md32_en_cfg_base);
> > +phy_set_bits(phydev, MII_BMCR, BMCR_RESET);
> > +/* We need a delay here to stabilize initialization of MCU */
> > +usleep_range(7000, 8000);
> > +dev_info(dev, "Firmware loading/trigger ok.\n");
> > +
> > +priv->fw_loaded = true;
> > +
> > +free:
> > +iounmap(md32_en_cfg_base);
> > +free_pmb:
> > +iounmap(pmb_addr);
> > +
> > +return ret ? ret : 0;
> 
> I'm feeling that I'm missing something incredibly obvious,
> but could this simply be:
> 
> return ret;
> 
> > +}
> 
> ...
Thanks. I'll fix like this:

static int mt798x_2p5ge_phy_load_fw(struct phy_device *phydev)
{
	int ret, i;
	...

	if (!md32_en_cfg_base) {
		ret = -ENOMEM;
		goto free_pmb;
	}

	ret = request_firmware(&fw, MT7988_2P5GE_PMB_FW, dev);
	if (ret) {
		dev_err(dev, "failed to load firmware: %s, ret: %d\n",
			MT7988_2P5GE_PMB_FW, ret);
		goto free;
	}

	if (fw->size != MT7988_2P5GE_PMB_FW_SIZE) {
		dev_err(dev, "Firmware size 0x%zx != 0x%x\n",
			fw->size, MT7988_2P5GE_PMB_FW_SIZE);
		ret = -EINVAL;
		goto release_fw;
	}

	...
	for (i = 0; i < MT7988_2P5GE_PMB_FW_SIZE - 1; i += 4)
		writel(*((uint32_t *)(fw->data + i)), pmb_addr + i);
	/* Remove original release_firmware(fw) here */
	...

release_fw:
	release_firmware(fw);
free:
	iounmap(md32_en_cfg_base);
free_pmb:
	iounmap(pmb_addr);

	return ret;
}

BRs,
Sky