Commit 7b95e20e authored by Alexander Stein's avatar Alexander Stein Committed by Shawn Guo
Browse files

soc: imx: imx93-blk-ctrl: Add dedicated lockdep class for nested genpd locks 



This is the same approach as being used within imx8mp-blk-ctrl. This fixes
the lockdep warning about 'possible recursive locking detected' with the
following (reduced) backtrace:
genpd_lock_mtx+0x14/0x1c
genpd_runtime_resume+0x108/0x308
__rpm_callback+0x44/0x19c
rpm_callback+0x64/0x70
rpm_resume+0x438/0x6d8
__pm_runtime_resume+0x54/0xb0
imx93_blk_ctrl_power_on+0x100/0x294
_genpd_power_on+0x8c/0x16c
genpd_power_on.part.0+0xa0/0x1a0
__genpd_dev_pm_attach+0x14c/0x2e4
genpd_dev_pm_attach+0x58/0x64
dev_pm_domain_attach+0x1c/0x2c

Signed-off-by: default avatarAlexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: default avatarShawn Guo <shawnguo@kernel.org>
parent 06c2afb8

drivers/soc/imx/imx93-blk-ctrl.c

+15 −0
Original line number Diff line number Diff line
@@ -187,6 +187,8 @@ static int imx93_blk_ctrl_power_off(struct generic_pm_domain *genpd) 
	return 0;

}



static struct lock_class_key blk_ctrl_genpd_lock_class;



static int imx93_blk_ctrl_probe(struct platform_device *pdev)

{

	struct device *dev = &pdev->dev;
@@ -269,6 +271,19 @@ static int imx93_blk_ctrl_probe(struct platform_device *pdev) 
			goto cleanup_pds;

		}



		/*

		 * We use runtime PM to trigger power on/off of the upstream GPC

		 * domain, as a strict hierarchical parent/child power domain

		 * setup doesn't allow us to meet the sequencing requirements.

		 * This means we have nested locking of genpd locks, without the

		 * nesting being visible at the genpd level, so we need a

		 * separate lock class to make lockdep aware of the fact that

		 * this are separate domain locks that can be nested without a

		 * self-deadlock.

		 */

		lockdep_set_class(&domain->genpd.mlock,

				  &blk_ctrl_genpd_lock_class);



		bc->onecell_data.domains[i] = &domain->genpd;

	}