On Thu, Jun 20, 2019 at 7:38 PM Matthias Brugger <matthias.bgg@xxxxxxxxx> wrote: > > CCing Sascha > > On 20/06/2019 11:35, Matthias Brugger wrote: > > > > > > On 13/06/2019 10:14, Pi-Hsun Shih wrote: > >> Hi, > >> When I tested this patch series (Based on linux 5.2.0-rc2, and with > >> various other patch series about MT8183) with lockdep enabled, and I'm > >> seeing the following lockdep warning on boot. > >> > >> By bisecting the commits, the first commit that introduce this warning > >> is this patch. The warning also doesn't appear if > >> https://lore.kernel.org/patchwork/patch/1086582/ and > >> https://lore.kernel.org/patchwork/patch/1086583/ are not applied. > >> > >> Do anyone have idea on why this is happening, or any suggestion on > >> which part I should be digging into to figure this out? Thanks. > >> > >> [ 4.664194] ====================================================== > >> [ 4.670368] WARNING: possible circular locking dependency detected > >> [ 4.676545] 5.2.0-rc2-next-20190528-44527-g6c94b6475c04 #20 Tainted: G S > >> [ 4.684539] ------------------------------------------------------ > >> [ 4.690714] kworker/4:1/51 is trying to acquire lock: > >> [ 4.695760] (____ptrval____) (regulator_list_mutex){+.+.}, > >> at:regulator_lock_dependent+0xdc/0x6c4 > >> [ 4.704732] > >> [ 4.704732] but task is already holding lock: > >> [ 4.710556] (____ptrval____) (&genpd->mlock/1){+.+.}, > >> at:genpd_lock_nested_mtx+0x24/0x30 > >> [ 4.718740] > >> [ 4.718740] which lock already depends on the new lock. > >> [ 4.718740] > >> [ 4.726908] > >> [ 4.726908] the existing dependency chain (in reverse order) is: > >> [ 4.734382] > >> [ 4.734382] -> #4 (&genpd->mlock/1){+.+.}: > >> [ 4.739963] __mutex_lock_common+0x1a0/0x1fe8 > >> [ 4.744836] mutex_lock_nested+0x40/0x50 > >> [ 4.749275] genpd_lock_nested_mtx+0x24/0x30 > >> [ 4.754063] genpd_add_subdomain+0x150/0x524 > >> [ 4.758850] pm_genpd_add_subdomain+0x3c/0x5c > >> [ 4.763723] scpsys_probe+0x520/0xe78 > >> [ 4.767902] platform_drv_probe+0xf4/0x134 > >> [ 4.772517] really_probe+0x214/0x4dc > >> [ 4.776696] driver_probe_device+0xcc/0x1d4 > >> [ 4.781396] __device_attach_driver+0x10c/0x180 > >> [ 4.786442] bus_for_each_drv+0x124/0x184 > >> [ 4.790968] __device_attach+0x1c0/0x2d8 > >> [ 4.795407] device_initial_probe+0x20/0x2c > >> [ 4.800106] bus_probe_device+0x80/0x16c > >> [ 4.804546] deferred_probe_work_func+0x120/0x168 > >> [ 4.809767] process_one_work+0x858/0x1208 > >> [ 4.814379] worker_thread+0x9ec/0xcb8 > >> [ 4.818644] kthread+0x2b8/0x2d0 > >> [ 4.822391] ret_from_fork+0x10/0x18 > >> [ 4.826480] > >> [ 4.826480] -> #3 (&genpd->mlock){+.+.}: > >> [ 4.831880] __mutex_lock_common+0x1a0/0x1fe8 > >> [ 4.836752] mutex_lock_nested+0x40/0x50 > >> [ 4.841190] genpd_lock_mtx+0x20/0x2c > >> [ 4.845369] genpd_runtime_resume+0x140/0x434 > >> [ 4.850241] __rpm_callback+0xb0/0x1e4 > >> [ 4.854506] rpm_callback+0x54/0x1a8 > >> [ 4.858597] rpm_resume+0xc6c/0x10c4 > >> [ 4.862689] __pm_runtime_resume+0xb4/0x124 > >> [ 4.867387] device_link_add+0x598/0x8d0 > > > > For this looks as if you have also patch > > [PATCH v2 04/12] memory: mtk-smi: Add device-link between smi-larb and smi-common > > from series > > [PATCH v2 00/12] Clean up "mediatek,larb" after adding device_link > > applied. > > > > My guess is, that we run into this, because we call genpd_runtime_resume before > we have finished the subdomain registration in scpsys_probe. > That implies that you also have the scpsys series for mt8183 added to your tree. > > Anyway it looks to me as if we have to add the subdomains before we call > of_genpd_add_provider_onecell(). > > Regards, > Matthias Yes I do have scpsys series for mt8183 added in my tree. (I have about 125 patches from list on top of 531b0a360899 "Add linux-next specific files for 20190528" to make the board boot) However the exact same warning still exists after I changed the order of of_genpd_add_provider_onecell and pm_genpd_add_subdomain, patch as follow: (Patch is based on commit f4788d37bc84 "Add linux-next specific files for 20190614") diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c index 503222d0d0da..0cd9bdd4004e 100644 --- a/drivers/soc/mediatek/mtk-scpsys.c +++ b/drivers/soc/mediatek/mtk-scpsys.c @@ -440,8 +440,7 @@ static struct scp *init_scp(struct platform_device *pdev, static void mtk_register_power_domains(struct platform_device *pdev, struct scp *scp, int num) { - struct genpd_onecell_data *pd_data; - int i, ret; + int i; for (i = 0; i < num; i++) { struct scp_domain *scpd = &scp->domains[i]; @@ -457,18 +456,6 @@ static void mtk_register_power_domains(struct platform_device *pdev, pm_genpd_init(genpd, NULL, false); } - - /* - * We are not allowed to fail here since there is no way to unregister - * a power domain. Once registered above we have to keep the domains - * valid. - */ - - pd_data = &scp->pd_data; - - ret = of_genpd_add_provider_onecell(pdev->dev.of_node, pd_data); - if (ret) - dev_err(&pdev->dev, "Failed to add OF provider: %d\n", ret); } /* @@ -1053,6 +1040,16 @@ static int scpsys_probe(struct platform_device *pdev) ret); } + /* + * We are not allowed to fail here since there is no way to unregister + * a power domain. Once registered above we have to keep the domains + * valid. + */ + + ret = of_genpd_add_provider_onecell(pdev->dev.of_node, pd_data); + if (ret) + dev_err(&pdev->dev, "Failed to add OF provider: %d\n", ret); + return 0; } > > > > Regards, > > Matthias > >
