17.12.2020 21:21, Mikko Perttunen пишет:

On 12/17/20 8:06 PM, Dmitry Osipenko wrote:

quoted

Add suspend/resume and generic power domain support to the Host1x driver.
This is required for enabling system-wide DVFS and supporting dynamic
power management using a generic power domain.

Tested-by: Peter Geis <redacted>
Tested-by: Nicolas Chauvet <redacted>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
  drivers/gpu/host1x/dev.c | 102 ++++++++++++++++++++++++++++++++++-----
  1 file changed, 91 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
index d0ebb70e2fdd..c1525cffe7b1 100644
--- a/drivers/gpu/host1x/dev.c
+++ b/drivers/gpu/host1x/dev.c

@@ -12,6 +12,7 @@

  #include <linux/module.h>
  #include <linux/of_device.h>
  #include <linux/of.h>
+#include <linux/pm_runtime.h>
  #include <linux/slab.h>
    #define CREATE_TRACE_POINTS

@@ -417,7 +418,7 @@ static int host1x_probe(struct platform_device *pdev)

          return err;
      }
  -    host->rst = devm_reset_control_get(&pdev->dev, "host1x");
+    host->rst = devm_reset_control_get_exclusive_released(&pdev->dev,
"host1x");
      if (IS_ERR(host->rst)) {
          err = PTR_ERR(host->rst);
          dev_err(&pdev->dev, "failed to get reset: %d\n", err);

@@ -437,16 +438,15 @@ static int host1x_probe(struct platform_device

*pdev)
          goto iommu_exit;
      }
  -    err = clk_prepare_enable(host->clk);
-    if (err < 0) {
-        dev_err(&pdev->dev, "failed to enable clock\n");
-        goto free_channels;
-    }
+    pm_runtime_enable(&pdev->dev);
+    err = pm_runtime_get_sync(&pdev->dev);
+    if (err < 0)
+        goto rpm_disable;
        err = reset_control_deassert(host->rst);
      if (err < 0) {
          dev_err(&pdev->dev, "failed to deassert reset: %d\n", err);
-        goto unprepare_disable;
+        goto rpm_disable;
      }
        err = host1x_syncpt_init(host);

@@ -485,9 +485,10 @@ static int host1x_probe(struct platform_device

*pdev)
      host1x_syncpt_deinit(host);
  reset_assert:
      reset_control_assert(host->rst);
-unprepare_disable:
-    clk_disable_unprepare(host->clk);
-free_channels:
+rpm_disable:
+    pm_runtime_put(&pdev->dev);
+    pm_runtime_disable(&pdev->dev);
+
      host1x_channel_list_free(&host->channel_list);
  iommu_exit:
      host1x_iommu_exit(host);

@@ -504,16 +505,95 @@ static int host1x_remove(struct platform_device

*pdev)
      host1x_intr_deinit(host);
      host1x_syncpt_deinit(host);
      reset_control_assert(host->rst);
-    clk_disable_unprepare(host->clk);
+    pm_runtime_put(&pdev->dev);
+    pm_runtime_disable(&pdev->dev);
      host1x_iommu_exit(host);
        return 0;
  }
  +static int __maybe_unused host1x_runtime_suspend(struct device *dev)
+{
+    struct host1x *host = dev_get_drvdata(dev);
+
+    clk_disable_unprepare(host->clk);
+    reset_control_release(host->rst);
+
+    return 0;
+}
+
+static int __maybe_unused host1x_runtime_resume(struct device *dev)
+{
+    struct host1x *host = dev_get_drvdata(dev);
+    int err;
+
+    err = reset_control_acquire(host->rst);
+    if (err) {
+        dev_err(dev, "failed to acquire reset: %d\n", err);
+        return err;
+    }
+
+    err = clk_prepare_enable(host->clk);
+    if (err) {
+        dev_err(dev, "failed to enable clock: %d\n", err);
+        goto release_reset;
+    }
+
+    return 0;
+
+release_reset:
+    reset_control_release(host->rst);
+
+    return err;
+}
+
+static __maybe_unused int host1x_suspend(struct device *dev)
+{
+    struct host1x *host = dev_get_drvdata(dev);
+    int err;
+
+    host1x_syncpt_save(host);
+
+    err = pm_runtime_force_suspend(dev);
+    if (err < 0)
+        return err;
+
+    return 0;
+}
+
+static __maybe_unused int host1x_resume(struct device *dev)
+{
+    struct host1x *host = dev_get_drvdata(dev);
+    struct host1x_channel *channel;
+    unsigned int index;
+    int err;
+
+    err = pm_runtime_force_resume(dev);
+    if (err < 0)
+        return err;
+
+    host1x_syncpt_restore(host);

We also need to execute 'host1x_setup_sid_table' upon resume.

Indeed, thanks. I'll correct it in the next revision.

Perhaps the actual save/restore needs to be moved to the runtime
callbacks. At least I can't remember right now why this wasn't done in
the first place.