Hi Vivek,
On Thu, Aug 30, 2018 at 11:46 PM Vivek Gautam
<vivek.gautam@xxxxxxxxxxxxxx> wrote:
>
> From: Sricharan R <sricharan@xxxxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxxxx>
> [vivek: Cleanup pm runtime calls]
> Signed-off-by: Vivek Gautam <vivek.gautam@xxxxxxxxxxxxxx>
> Reviewed-by: Tomasz Figa <tfiga@xxxxxxxxxxxx>
> Tested-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> ---
> 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.
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
