From: Vitor Soares vitor.soares@toradex.com
During the probe, the genpd power_dev is added to the dpm_list after blk_ctrl due to its parent/child relationship. Making the blk_ctrl suspend after and resume before the genpd power_dev.
As a consequence, the system hangs when resuming the VPU due to the power domain dependency.
To ensure the proper suspend/resume order, add a device link betweem blk_ctrl and genpd power_dev. It guarantees genpd power_dev is suspended after and resumed before blk-ctrl.
Cc: stable@vger.kernel.org Closes: https://lore.kernel.org/all/fccbb040330a706a4f7b34875db1d896a0bf81c8.camel@g... Link: https://lore.kernel.org/all/20240409085802.290439-1-ivitro@gmail.com/ Fixes: 2684ac05a8c4 ("soc: imx: add i.MX8M blk-ctrl driver") Suggested-by: Lucas Stach l.stach@pengutronix.de Signed-off-by: Vitor Soares vitor.soares@toradex.com ---
This is a new patch, but is a follow-up of: https://lore.kernel.org/all/20240409085802.290439-1-ivitro@gmail.com/
As suggested by Lucas, we are addressing this PM issue in the imx8m-blk-ctrl driver instead of in the imx8mm.dtsi.
drivers/pmdomain/imx/imx8m-blk-ctrl.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)
diff --git a/drivers/pmdomain/imx/imx8m-blk-ctrl.c b/drivers/pmdomain/imx/imx8m-blk-ctrl.c index ca942d7929c2..cd0d2296080d 100644 --- a/drivers/pmdomain/imx/imx8m-blk-ctrl.c +++ b/drivers/pmdomain/imx/imx8m-blk-ctrl.c @@ -283,6 +283,20 @@ static int imx8m_blk_ctrl_probe(struct platform_device *pdev) goto cleanup_pds; }
+ /* + * Enforce suspend/resume ordering by making genpd power_dev a + * provider of blk-ctrl. Genpd power_dev is suspended after and + * resumed before blk-ctrl. + */ + if (!device_link_add(dev, domain->power_dev, DL_FLAG_STATELESS)) { + ret = -EINVAL; + dev_err_probe(dev, ret, + "failed to link to %s\n", data->name); + pm_genpd_remove(&domain->genpd); + dev_pm_domain_detach(domain->power_dev, true); + 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 @@ -324,6 +338,7 @@ static int imx8m_blk_ctrl_probe(struct platform_device *pdev) of_genpd_del_provider(dev->of_node); cleanup_pds: for (i--; i >= 0; i--) { + device_link_remove(dev, bc->domains[i].power_dev); pm_genpd_remove(&bc->domains[i].genpd); dev_pm_domain_detach(bc->domains[i].power_dev, true); } @@ -343,6 +358,7 @@ static void imx8m_blk_ctrl_remove(struct platform_device *pdev) for (i = 0; bc->onecell_data.num_domains; i++) { struct imx8m_blk_ctrl_domain *domain = &bc->domains[i];
+ device_link_remove(&pdev->dev, domain->power_dev); pm_genpd_remove(&domain->genpd); dev_pm_domain_detach(domain->power_dev, true); }