Re: [PATCH v4 1/6] phy: qcom-qmp-pcie: split register tables into common and extra parts

From: Johan Hovold <johan@kernel.org>
To: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: "Andy Gross" <agross@kernel.org>,
	"Bjorn Andersson" <andersson@kernel.org>,
	"Konrad Dybcio" <konrad.dybcio@somainline.org>,
	"Rob Herring" <robh+dt@kernel.org>,
	"Jingoo Han" <jingoohan1@gmail.com>,
	"Gustavo Pimentel" <gustavo.pimentel@synopsys.com>,
	"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Bjorn Helgaas" <bhelgaas@google.com>,
	"Vinod Koul" <vkoul@kernel.org>,
	"Kishon Vijay Abraham I" <kishon@ti.com>,
	"Philipp Zabel" <p.zabel@pengutronix.de>,
	linux-arm-msm@vger.kernel.org, linux-pci@vger.kernel.org,
	linux-phy@lists.infradead.org
Subject: Re: [PATCH v4 1/6] phy: qcom-qmp-pcie: split register tables into common and extra parts
Date: Mon, 26 Sep 2022 08:32:43 +0200	[thread overview]
Message-ID: <YzFHi3IQcBF70uCG@hovoldconsulting.com> (raw)
In-Reply-To: <20220924160302.285875-2-dmitry.baryshkov@linaro.org>

On Sat, Sep 24, 2022 at 07:02:57PM +0300, Dmitry Baryshkov wrote:
> SM8250 configuration tables are split into two parts: the common one and
> the PHY-specific tables. Make this split more formal. Rather than having
> a blind renamed copy of all QMP table fields, add separate struct
> qmp_phy_cfg_tables and add two instances of this structure to the struct
> qmp_phy_cfg. Later on this will be used to support different PHY modes
> (RC vs EP).
> 
> Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
> ---
>  drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 129 ++++++++++++++---------
>  1 file changed, 77 insertions(+), 52 deletions(-)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> index 7aff3f9940a5..30806816c8b0 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
> @@ -1300,31 +1300,30 @@ static const struct qmp_phy_init_tbl sm8450_qmp_gen4x2_pcie_pcs_misc_tbl[] = {
>  	QMP_PHY_INIT_CFG(QPHY_V5_20_PCS_PCIE_G4_PRE_GAIN, 0x2e),
>  };
>  
> -/* struct qmp_phy_cfg - per-PHY initialization config */
> -struct qmp_phy_cfg {
> -	int lanes;
> -
> -	/* Init sequence for PHY blocks - serdes, tx, rx, pcs */
> +struct qmp_phy_cfg_tables {
>  	const struct qmp_phy_init_tbl *serdes_tbl;
>  	int serdes_tbl_num;
> -	const struct qmp_phy_init_tbl *serdes_tbl_sec;
> -	int serdes_tbl_num_sec;
>  	const struct qmp_phy_init_tbl *tx_tbl;
>  	int tx_tbl_num;
> -	const struct qmp_phy_init_tbl *tx_tbl_sec;
> -	int tx_tbl_num_sec;
>  	const struct qmp_phy_init_tbl *rx_tbl;
>  	int rx_tbl_num;
> -	const struct qmp_phy_init_tbl *rx_tbl_sec;
> -	int rx_tbl_num_sec;
>  	const struct qmp_phy_init_tbl *pcs_tbl;
>  	int pcs_tbl_num;
> -	const struct qmp_phy_init_tbl *pcs_tbl_sec;
> -	int pcs_tbl_num_sec;
>  	const struct qmp_phy_init_tbl *pcs_misc_tbl;
>  	int pcs_misc_tbl_num;
> -	const struct qmp_phy_init_tbl *pcs_misc_tbl_sec;
> -	int pcs_misc_tbl_num_sec;
> +};
> +
> +/* struct qmp_phy_cfg - per-PHY initialization config */
> +struct qmp_phy_cfg {
> +	int lanes;
> +
> +	/* Main init sequence for PHY blocks - serdes, tx, rx, pcs */
> +	struct qmp_phy_cfg_tables common;
> +	/*
> +	 * Additional init sequence for PHY blocks, providing additional
> +	 * register programming. Unless required it can be left omitted.
> +	 */
> +	struct qmp_phy_cfg_tables *extra;
>  
>  	/* clock ids to be requested */
>  	const char * const *clk_list;

> @@ -1949,31 +1974,31 @@ static int qmp_pcie_power_on(struct phy *phy)
>  	}
>  
>  	/* Tx, Rx, and PCS configurations */
> -	qmp_pcie_configure_lane(tx, cfg->regs, cfg->tx_tbl, cfg->tx_tbl_num, 1);
> -	qmp_pcie_configure_lane(tx, cfg->regs, cfg->tx_tbl_sec, cfg->tx_tbl_num_sec, 1);
> +	qmp_pcie_configure_lane(tx, cfg->regs, cfg->common.tx_tbl, cfg->common.tx_tbl_num, 1);
> +	qmp_pcie_configure_lane(tx, cfg->regs, cfg->extra->tx_tbl, cfg->extra->tx_tbl_num, 1);

Hmm. How did you test this?

With your later versions of this series, cfg->extra is generally NULL so
this would dereference a NULL pointer.

Johan