Messages in this thread | | | Subject | Re: [PATCH v16 2/5] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device | From | Vivek Gautam <> | Date | Fri, 7 Sep 2018 15:08:02 +0530 |
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Hi Tomasz,
On 9/7/2018 2:46 PM, Tomasz Figa wrote: > Hi Vivek, > > On Thu, Aug 30, 2018 at 11:46 PM Vivek Gautam > <vivek.gautam@codeaurora.org> wrote: >> From: Sricharan R <sricharan@codeaurora.org> >> >> The smmu device probe/remove and add/remove master device callbacks >> gets called when the smmu is not linked to its master, that is without >> the context of the master device. So calling runtime apis in those places >> separately. >> Global locks are also initialized before enabling runtime pm as the >> runtime_resume() calls device_reset() which does tlb_sync_global() >> that ultimately requires locks to be initialized. >> >> Signed-off-by: Sricharan R <sricharan@codeaurora.org> >> [vivek: Cleanup pm runtime calls] >> Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org> >> Reviewed-by: Tomasz Figa <tfiga@chromium.org> >> Tested-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> >> --- >> drivers/iommu/arm-smmu.c | 89 +++++++++++++++++++++++++++++++++++++++++++----- >> 1 file changed, 81 insertions(+), 8 deletions(-) > [snip] >> @@ -2215,10 +2281,17 @@ static int arm_smmu_device_remove(struct platform_device *pdev) >> if (!bitmap_empty(smmu->context_map, ARM_SMMU_MAX_CBS)) >> dev_err(&pdev->dev, "removing device with active domains!\n"); >> >> + arm_smmu_rpm_get(smmu); >> /* Turn the thing off */ >> writel(sCR0_CLIENTPD, ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0); >> + arm_smmu_rpm_put(smmu); >> + >> + if (pm_runtime_enabled(smmu->dev)) >> + pm_runtime_force_suspend(smmu->dev); >> + else >> + clk_bulk_disable(smmu->num_clks, smmu->clks); >> >> - clk_bulk_disable_unprepare(smmu->num_clks, smmu->clks); >> + clk_bulk_unprepare(smmu->num_clks, smmu->clks); > Aren't we missing pm_runtime_disable() here? We'll have the enable > count unbalanced if the driver is removed and probed again.
pm_runtime_force_suspend() does a pm_runtime_disable() also if i am not wrong. And, as mentioned in a previous thread [1], we were seeing a warning which we avoided by keeping force_suspend().
[1] https://lkml.org/lkml/2018/7/8/124
Thanks Vivek > > Also, if we add pm_runtime_disable(), we can reorder things a bit and > simplify into: > > arm_smmu_rpm_get(smmu); > > /* Turn the thing off */ > writel(sCR0_CLIENTPD, ARM_SMMU_GR0_NS(smmu) + ARM_SMMU_GR0_sCR0); > > if (pm_runtime_enabled()) > pm_runtime_disable(); > arm_smmu_rpm_put(smmu); > > clk_bulk_disable_unprepare(smmu->num_clks, smmu->clks); > > Best regards, > Tomasz
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