On Thu, Aug 30, 2018 at 6:22 PM Vivek Gautam
[off-list ref] wrote:

On Mon, Aug 27, 2018 at 4:27 PM Vivek Gautam
[off-list ref] wrote:

quoted

From: Sricharan R <redacted>

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.

Signed-off-by: Sricharan R <redacted>
[vivek: Cleanup pm runtime calls]
Signed-off-by: Vivek Gautam <redacted>
Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Tested-by: Srinivas Kandagatla <redacted>
---

Changes since v14:
 - none.

 drivers/iommu/arm-smmu.c | 101 +++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 93 insertions(+), 8 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index a81224bc6637..23b4a60149b6 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c

[snip]

quoted

@@ -2131,6 +2188,26 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
        if (err)
                return err;

+       /*
+        * We want to avoid touching dev->power.lock in fastpaths unless
+        * it's really going to do something useful - pm_runtime_enabled()
+        * can serve as an ideal proxy for that decision. So, conditionally
+        * enable pm_runtime.
+        */
+       if (dev->pm_domain)
+               pm_runtime_enable(dev);
+
+       err = arm_smmu_rpm_get(smmu);

We shouldn't be doing a runtime_get() yet, as this eventually calls
arm_smmu_device_reset().
arm_smmu_device_reset() should be called only after arm_smmu_device_cfg_probe().
So, I plan to replace the pm_runtime_get/put() calls in probe() with
simple clk_bulk_enable()
to let the driver initialize smmu, and at the end of the probe we can
disable the clocks and
enable runtime pm over the device to let it take care of the device further-on.

We can avoid the explicit clock disable by just calling
pm_runtime_set_active() before pm_runtime_enable(), assuming that what
probe does is symmetrical with the suspend callback, which would be
called after the latter.

Best regards,
Tomasz
_______________________________________________
Freedreno mailing list
Freedreno@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/freedreno