[PATCH] pmdomain: imx: Fix i.MX8MP VPU_H1 power up sequence
From: Peng Fan (OSS) <hidden>
Date: 2026-01-28 15:11:52
Also in:
imx, linux-pm, lkml, stable
Subsystem:
generic pm domains, the rest · Maintainers:
Ulf Hansson, Linus Torvalds
From: Peng Fan <peng.fan@nxp.com>
Per errata:
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.
While at here, using imx8mm_vpu_power_notifier() is wrong, as it ungates
the VPU clocks to provide the ADB clock, which is necessary on i.MX8MM,
but on i.MX8MP there is a separate gate (bit 3) for the NoC. So add
imx8mp_vpu_power_notifier() for i.MX8MP.
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>
---
drivers/pmdomain/imx/imx8m-blk-ctrl.c | 37 +++++++++++++++++++++++++++++++++--
1 file changed, 35 insertions(+), 2 deletions(-)
diff --git a/drivers/pmdomain/imx/imx8m-blk-ctrl.c b/drivers/pmdomain/imx/imx8m-blk-ctrl.c
index 74bf4936991d7c36346797d8b646dad40085fc2d..5b26b7c2c43172817d5e407a7d85eb6c5400d5a8 100644
--- a/drivers/pmdomain/imx/imx8m-blk-ctrl.c
+++ b/drivers/pmdomain/imx/imx8m-blk-ctrl.c@@ -54,6 +54,7 @@ struct imx8m_blk_ctrl_domain_data { * register. */ u32 mipi_phy_rst_mask; + bool is_errata_err050531; }; #define DOMAIN_MAX_CLKS 4
@@ -108,7 +109,11 @@ 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 +122,9 @@ 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);
@@ -514,9 +522,34 @@ static const struct imx8m_blk_ctrl_domain_data imx8mp_vpu_blk_ctl_domain_data[] }, }; +static int imx8mp_vpu_power_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct imx8m_blk_ctrl *bc = container_of(nb, struct imx8m_blk_ctrl, + power_nb); + + if (action == GENPD_NOTIFY_ON) { + /* + * On power up we have no software backchannel to the GPC to + * wait for the ADB handshake to happen, so we just delay for a + * bit. On power down the GPC driver waits for the handshake. + */ + + udelay(5); + + /* set "fuse" bits to enable the VPUs */ + regmap_set_bits(bc->regmap, 0x8, 0xffffffff); + regmap_set_bits(bc->regmap, 0xc, 0xffffffff); + regmap_set_bits(bc->regmap, 0x10, 0xffffffff); + regmap_set_bits(bc->regmap, 0x14, 0xffffffff); + } + + return NOTIFY_OK; +} + static const struct imx8m_blk_ctrl_data imx8mp_vpu_blk_ctl_dev_data = { .max_reg = 0x18, - .power_notifier_fn = imx8mm_vpu_power_notifier, + .power_notifier_fn = imx8mp_vpu_power_notifier, .domains = imx8mp_vpu_blk_ctl_domain_data, .num_domains = ARRAY_SIZE(imx8mp_vpu_blk_ctl_domain_data), };
--- base-commit: 4f938c7d3b25d87b356af4106c2682caf8c835a2 change-id: 20260128-imx8mp-vc8000e-pm-4278e6d48b54 Best regards, -- Peng Fan [off-list ref]