From d4905ce38c73964b868037e49a5945e1cf47a7f2 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Tue, 31 May 2011 15:23:20 +0900 Subject: [PATCH 1/3] Revert "clocksource: sh_tmu: Runtime PM support" This reverts commit 1b842e91fea9447eff5eb687e28ad61c02f5033e. There is a fundamental ordering race between the early and late probe paths and the runtime PM tie-in that results in __pm_runtime_resume() attempting to take a lock that hasn't been initialized yet (which by proxy also suggests that pm_runtime_init() hasn't yet been run on the device either, making the entire thing unsafe) -- resulting in instant death on SMP or on UP with spinlock debugging enabled: sh_tmu.0: used for clock events sh_tmu.0: used for periodic clock events BUG: spinlock trylock failure on UP on CPU#0, swapper/0 lock: 804db198, .magic: 00000000, .owner: /-1, .owner_cpu: 0 ... Revert it for now until the ordering issues can be resolved, or we can get some more help from the runtime PM framework to make this possible. Signed-off-by: Paul Mundt --- drivers/clocksource/sh_tmu.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/drivers/clocksource/sh_tmu.c b/drivers/clocksource/sh_tmu.c index 17296288a205..808135768617 100644 --- a/drivers/clocksource/sh_tmu.c +++ b/drivers/clocksource/sh_tmu.c @@ -25,7 +25,6 @@ #include #include #include -#include #include #include #include @@ -110,12 +109,10 @@ static int sh_tmu_enable(struct sh_tmu_priv *p) { int ret; - /* wake up device and enable clock */ - pm_runtime_get_sync(&p->pdev->dev); + /* enable clock */ ret = clk_enable(p->clk); if (ret) { dev_err(&p->pdev->dev, "cannot enable clock\n"); - pm_runtime_put_sync(&p->pdev->dev); return ret; } @@ -144,9 +141,8 @@ static void sh_tmu_disable(struct sh_tmu_priv *p) /* disable interrupts in TMU block */ sh_tmu_write(p, TCR, 0x0000); - /* stop clock and mark device as idle */ + /* stop clock */ clk_disable(p->clk); - pm_runtime_put_sync(&p->pdev->dev); } static void sh_tmu_set_next(struct sh_tmu_priv *p, unsigned long delta, @@ -415,7 +411,6 @@ static int __devinit sh_tmu_probe(struct platform_device *pdev) if (p) { dev_info(&pdev->dev, "kept as earlytimer\n"); - pm_runtime_enable(&pdev->dev); return 0; } @@ -430,9 +425,6 @@ static int __devinit sh_tmu_probe(struct platform_device *pdev) kfree(p); platform_set_drvdata(pdev, NULL); } - - if (!is_early_platform_device(pdev)) - pm_runtime_enable(&pdev->dev); return ret; } From 9436b4abec28a22edd961ae375535d940625f1f2 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Tue, 31 May 2011 15:26:42 +0900 Subject: [PATCH 2/3] Revert "clocksource: sh_cmt: Runtime PM support" This reverts commit 01fa68b58492a5d6708a91c1f474b6a099a9509e. The same note as per the sh_tmu change applies here, too. Signed-off-by: Paul Mundt --- drivers/clocksource/sh_cmt.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c index 036e5865eb40..dc7c033ef587 100644 --- a/drivers/clocksource/sh_cmt.c +++ b/drivers/clocksource/sh_cmt.c @@ -24,7 +24,6 @@ #include #include #include -#include #include #include #include @@ -153,12 +152,10 @@ static int sh_cmt_enable(struct sh_cmt_priv *p, unsigned long *rate) { int ret; - /* wake up device and enable clock */ - pm_runtime_get_sync(&p->pdev->dev); + /* enable clock */ ret = clk_enable(p->clk); if (ret) { dev_err(&p->pdev->dev, "cannot enable clock\n"); - pm_runtime_put_sync(&p->pdev->dev); return ret; } @@ -190,9 +187,8 @@ static void sh_cmt_disable(struct sh_cmt_priv *p) /* disable interrupts in CMT block */ sh_cmt_write(p, CMCSR, 0); - /* stop clock and mark device as idle */ + /* stop clock */ clk_disable(p->clk); - pm_runtime_put_sync(&p->pdev->dev); } /* private flags */ @@ -664,7 +660,6 @@ static int __devinit sh_cmt_probe(struct platform_device *pdev) if (p) { dev_info(&pdev->dev, "kept as earlytimer\n"); - pm_runtime_enable(&pdev->dev); return 0; } @@ -679,9 +674,6 @@ static int __devinit sh_cmt_probe(struct platform_device *pdev) kfree(p); platform_set_drvdata(pdev, NULL); } - - if (!is_early_platform_device(pdev)) - pm_runtime_enable(&pdev->dev); return ret; } From 5c2de44417523385010b529599a2b30f290831a3 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Tue, 31 May 2011 15:53:03 +0900 Subject: [PATCH 3/3] dmaengine: shdma: Fix up fallout from runtime PM changes. The runtime PM changes introduce sh_dmae_rst() wrapping via the runtime_resume helper, depending on dev_get_drvdata() to fetch the platform data needed for the DMAOR initialization default at a time where drvdata hasn't yet been established by the probe path, resulting in general probe misery: Unable to handle kernel NULL pointer dereference at virtual address 000000c4 pc = 8025adee *pde = 00000000 Oops: 0000 [#1] Modules linked in: Pid : 1, Comm: swapper CPU : 0 Not tainted (3.0.0-rc1-00012-g9436b4a-dirty #1456) PC is at sh_dmae_rst+0x28/0x86 PR is at sh_dmae_rst+0x22/0x86 PC : 8025adee SP : 9e803d10 SR : 400080f1 TEA : 000000c4 R0 : 000000c4 R1 : 0000fff8 R2 : 00000000 R3 : 00000040 R4 : 000000f0 R5 : 00000000 R6 : 00000000 R7 : 804f184c R8 : 00000000 R9 : 804dd0e8 R10 : 80283204 R11 : ffffffda R12 : 000000a0 R13 : 804dd18c R14 : 9e803d10 MACH: 00000000 MACL: 00008f20 GBR : 00000000 PR : 8025ade8 Call trace: [<8025ae70>] sh_dmae_runtime_resume+0x24/0x34 [<80283238>] pm_generic_runtime_resume+0x34/0x3c [<80283370>] rpm_callback+0x4a/0x7e [<80283efc>] rpm_resume+0x240/0x384 [<80283f54>] rpm_resume+0x298/0x384 [<8028428c>] __pm_runtime_resume+0x44/0x7c [<8038a358>] __ioremap_caller+0x0/0xec [<80284296>] __pm_runtime_resume+0x4e/0x7c [<8038a358>] __ioremap_caller+0x0/0xec [<80666254>] sh_dmae_probe+0x180/0x6a0 [<802803ae>] platform_drv_probe+0x26/0x2e Fix up the ordering accordingly. Signed-off-by: Paul Mundt --- drivers/dma/shdma.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/dma/shdma.c b/drivers/dma/shdma.c index 636e40925b16..727e76ff13e1 100644 --- a/drivers/dma/shdma.c +++ b/drivers/dma/shdma.c @@ -1144,6 +1144,8 @@ static int __init sh_dmae_probe(struct platform_device *pdev) /* platform data */ shdev->pdata = pdata; + platform_set_drvdata(pdev, shdev); + pm_runtime_enable(&pdev->dev); pm_runtime_get_sync(&pdev->dev); @@ -1256,7 +1258,6 @@ static int __init sh_dmae_probe(struct platform_device *pdev) pm_runtime_put(&pdev->dev); - platform_set_drvdata(pdev, shdev); dma_async_device_register(&shdev->common); return err; @@ -1278,6 +1279,8 @@ static int __init sh_dmae_probe(struct platform_device *pdev) if (dmars) iounmap(shdev->dmars); + + platform_set_drvdata(pdev, NULL); emapdmars: iounmap(shdev->chan_reg); synchronize_rcu(); @@ -1316,6 +1319,8 @@ static int __exit sh_dmae_remove(struct platform_device *pdev) iounmap(shdev->dmars); iounmap(shdev->chan_reg); + platform_set_drvdata(pdev, NULL); + synchronize_rcu(); kfree(shdev);