Re: [PATCH v4 2/2] pmdomain: imx: Fix i.MX8MP VC8000E power up sequence

[Frank Li <Frank.li@oss.nxp.com>]

On Wed, Jun 10, 2026 at 10:39:11PM +0800, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@nxp.com>
>
> Per errata[1]:
> ERR050531: VPU_NOC power down handshake may hang during VC8000E/VPUMIX
> power up/down cycling.
> Description: VC8000E reset de-assertion edge and AXI clock may have a
> timing issue.
> Workaround: Set bit2 (vc8000e_clk_en) of BLK_CLK_EN_CSR to 0 to gate off
> both AXI clock and VC8000E clock sent to VC8000E and AXI clock sent to
> VPU_NOC m_v_2 interface during VC8000E power up(VC8000E reset is
> de-asserted by HW)
>
> Add a bool variable is_errata_err050531 in
> 'struct imx8m_blk_ctrl_domain_data' to represent whether the workaround
> is needed. If is_errata_err050531 is true, first clear the clk before
> powering up gpc, then enable the clk after powering up gpc.
>
> [1] https://www.nxp.com/webapp/Download?colCode=IMX8MP_1P33A
>
> Fixes: a1a5f15f7f6cb ("soc: imx: imx8m-blk-ctrl: add i.MX8MP VPU blk ctrl")
> Cc: stable@vger.kernel.org
> Signed-off-by: Peng Fan <peng.fan@nxp.com>
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  drivers/pmdomain/imx/imx8m-blk-ctrl.c | 19 ++++++++++++++++++-
>  1 file changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pmdomain/imx/imx8m-blk-ctrl.c b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> index e13a47eeed75..99d100e1d923 100644
> --- a/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> +++ b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
> @@ -54,6 +54,15 @@ struct imx8m_blk_ctrl_domain_data {
>  	 * register.
>  	 */
>  	u32 mipi_phy_rst_mask;
> +
> +	/*
> +	 * VC8000E reset de-assertion edge and AXI clock may have a timing issue.
> +	 * Workaround: Set bit2 (vc8000e_clk_en) of BLK_CLK_EN_CSR to 0 to gate off
> +	 * both AXI clock and VC8000E clock sent to VC8000E and AXI clock sent to
> +	 * VPU_NOC m_v_2 interface during VC8000E power up(VC8000E reset is
> +	 * de-asserted by HW)
> +	 */
> +	bool is_errata_err050531;
>  };
>
>  #define DOMAIN_MAX_CLKS 4
> @@ -108,7 +117,11 @@ static int imx8m_blk_ctrl_power_on(struct generic_pm_domain *genpd)
>  		dev_err(bc->dev, "failed to enable clocks\n");
>  		goto bus_put;
>  	}
> -	regmap_set_bits(bc->regmap, BLK_CLK_EN, data->clk_mask);
> +
> +	if (data->is_errata_err050531)
> +		regmap_clear_bits(bc->regmap, BLK_CLK_EN, data->clk_mask);
> +	else
> +		regmap_set_bits(bc->regmap, BLK_CLK_EN, data->clk_mask);
>
>  	/* power up upstream GPC domain */
>  	ret = pm_runtime_get_sync(domain->power_dev);
> @@ -117,6 +130,9 @@ static int imx8m_blk_ctrl_power_on(struct generic_pm_domain *genpd)
>  		goto clk_disable;
>  	}
>
> +	if (data->is_errata_err050531)
> +		regmap_set_bits(bc->regmap, BLK_CLK_EN, data->clk_mask);
> +
>  	/* wait for reset to propagate */
>  	udelay(5);
>
> @@ -511,6 +527,7 @@ static const struct imx8m_blk_ctrl_domain_data imx8mp_vpu_blk_ctl_domain_data[]
>  		.clk_mask = BIT(2),
>  		.path_names = (const char *[]){"vc8000e"},
>  		.num_paths = 1,
> +		.is_errata_err050531 = true,
>  	},
>  };
>
>
> --
> 2.51.0
>
>