[PATCH] media: hantro: disable runtime PM before hardware teardown

[PATCH] media: hantro: disable runtime PM before hardware teardown

[Tharit Tangkijwanichakul]

Removing the Hantro driver may trigger an SError on RK3588:
	SError Interrupt on CPU6, code 0x00000000be000011 -- SError
	...
	do_serror+0x5c/0x74
	el1h_64_error_handler+0x34/0x50
	el1h_64_error+0x6c/0x70
	regmap_mmio_read32le+0x10/0x20 (P)
	_regmap_bus_reg_read+0x6c/0xb4
	_regmap_read+0x60/0xdc
	regmap_read+0x4c/0x80
	rockchip_pd_power+0xe4/0x600
	rockchip_pd_power_off+0x1c/0x60
	_genpd_power_off+0x98/0x198
	genpd_power_off.part.0+0x178/0x288
	genpd_runtime_suspend+0x210/0x300
	__rpm_callback+0x48/0x1e0
	rpm_callback+0x74/0x80
	rpm_suspend+0x10c/0x580
	rpm_idle+0x134/0x1b8
	update_autosuspend+0x30/0xc4
	__pm_runtime_use_autosuspend+0x48/0x64
	hantro_remove+0x8c/0xa8 [hantro_vpu]
	...

hantro_remove() currently asserts the device resets before disabling
runtime PM.

Calling pm_runtime_dont_use_autosuspend() causes an idle device to be
runtime-suspended immediately. At that point the Hantro hardware has
already been torn down, while the generic power-domain genpd code
still performs the power-off sequence. genpd regmap_mmio_read causes panic
subsequently because the reset lines were asserted.

Disable runtime PM before asserting the reset lines so that no runtime-PM
transition can race with hardware teardown.

Apply the same ordering to the probe error paths as well.

Fixes: ea71631b7129 ("media: hantro: add support for reset lines")
Signed-off-by: Tharit Tangkijwanichakul <tharitt97@gmail.com>
---
 drivers/media/platform/verisilicon/hantro_drv.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/verisilicon/hantro_drv.c b/drivers/media/platform/verisilicon/hantro_drv.c
index 2e81877f640f..bbeec5ae509a 100644
--- a/drivers/media/platform/verisilicon/hantro_drv.c
+++ b/drivers/media/platform/verisilicon/hantro_drv.c
@@ -1212,7 +1212,7 @@ static int hantro_probe(struct platform_device *pdev)
 	ret = clk_bulk_prepare(vpu->variant->num_clocks, vpu->clocks);
 	if (ret) {
 		dev_err(&pdev->dev, "Failed to prepare clocks\n");
-		goto err_rst_assert;
+		goto err_pm_disable_assert_reset;
 	}
 
 	ret = v4l2_device_register(&pdev->dev, &vpu->v4l2_dev);
@@ -1266,8 +1266,11 @@ static int hantro_probe(struct platform_device *pdev)
 	v4l2_device_unregister(&vpu->v4l2_dev);
 err_clk_unprepare:
 	clk_bulk_unprepare(vpu->variant->num_clocks, vpu->clocks);
-err_rst_assert:
+err_pm_disable_assert_reset:
+	pm_runtime_dont_use_autosuspend(vpu->dev);
+	pm_runtime_disable(vpu->dev);
 	reset_control_assert(vpu->resets);
+	return ret;
 err_pm_disable:
 	pm_runtime_dont_use_autosuspend(vpu->dev);
 	pm_runtime_disable(vpu->dev);
@@ -1287,9 +1290,9 @@ static void hantro_remove(struct platform_device *pdev)
 	v4l2_m2m_put(vpu->m2m_dev);
 	v4l2_device_unregister(&vpu->v4l2_dev);
 	clk_bulk_unprepare(vpu->variant->num_clocks, vpu->clocks);
-	reset_control_assert(vpu->resets);
 	pm_runtime_dont_use_autosuspend(vpu->dev);
 	pm_runtime_disable(vpu->dev);
+	reset_control_assert(vpu->resets);
 }
 
 #ifdef CONFIG_PM

base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482
-- 
2.47.3