Re: [PATCH 1/5] drm/msm/adreno: Use OPP for every GPU generation
From: Dmitry Baryshkov
Date: Wed Feb 22 2023 - 17:47:44 EST
On 22/02/2023 23:47, Konrad Dybcio wrote:
Some older GPUs (namely a2xx with no opp tables at all and a320 with
downstream-remnants gpu pwrlevels) used not to have OPP tables. They
both however had just one frequency defined, making it extremely easy
to construct such an OPP table from within the driver if need be.
Do so and switch all clk_set_rate calls on core_clk to their OPP
counterparts.
Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxx>
---
drivers/gpu/drm/msm/adreno/adreno_gpu.c | 94 +++++++++++++++------------------
drivers/gpu/drm/msm/msm_gpu.c | 4 +-
drivers/gpu/drm/msm/msm_gpu_devfreq.c | 2 +-
3 files changed, 45 insertions(+), 55 deletions(-)
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index ce6b76c45b6f..9b940c0f063f 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -922,73 +922,50 @@ void adreno_wait_ring(struct msm_ringbuffer *ring, uint32_t ndwords)
ring->id);
}
-/* Get legacy powerlevels from qcom,gpu-pwrlevels and populate the opp table */
-static int adreno_get_legacy_pwrlevels(struct device *dev)
-{
- struct device_node *child, *node;
- int ret;
-
- node = of_get_compatible_child(dev->of_node, "qcom,gpu-pwrlevels");
- if (!node) {
- DRM_DEV_DEBUG(dev, "Could not find the GPU powerlevels\n");
- return -ENXIO;
- }
-
- for_each_child_of_node(node, child) {
- unsigned int val;
-
- ret = of_property_read_u32(child, "qcom,gpu-freq", &val);
- if (ret)
- continue;
-
- /*
- * Skip the intentionally bogus clock value found at the bottom
- * of most legacy frequency tables
- */
- if (val != 27000000)
- dev_pm_opp_add(dev, val, 0);
- }
-
- of_node_put(node);
-
- return 0;
-}
-
-static void adreno_get_pwrlevels(struct device *dev,
+static int adreno_get_pwrlevels(struct device *dev,
struct msm_gpu *gpu)
{
+ struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
unsigned long freq = ULONG_MAX;
struct dev_pm_opp *opp;
int ret;
gpu->fast_rate = 0;
- /* You down with OPP? */
- if (!of_find_property(dev->of_node, "operating-points-v2", NULL))
- ret = adreno_get_legacy_pwrlevels(dev);
- else {
- ret = devm_pm_opp_of_add_table(dev);
- if (ret)
- DRM_DEV_ERROR(dev, "Unable to set the OPP table\n");
- }
-
- if (!ret) {
+ /* devm_pm_opp_of_add_table may error out but will still create an OPP table */
+ ret = devm_pm_opp_of_add_table(dev);
+ if (ret == -ENODEV) {
+ /* Special cases for ancient hw with ancient DT bindings */
+ if (adreno_is_a2xx(adreno_gpu)) {
+ dev_warn(dev, "Unable to find the OPP table. Falling back to 200 MHz.\n");
+ dev_pm_opp_add(dev, 200000000, 0);
+ gpu->fast_rate = 200000000;
We can skip setting the fast_rate, dev_pm_opp_find_freq_floor below will
get it from our freshly generated opp table.
+ } else if (adreno_is_a320(adreno_gpu)) {
+ dev_warn(dev, "Unable to find the OPP table. Falling back to 450 MHz.\n");
+ dev_pm_opp_add(dev, 450000000, 0);
+ gpu->fast_rate = 450000000;
+ } else {
+ DRM_DEV_ERROR(dev, "Unable to find the OPP table\n");
+ return -ENODEV;
+ }
+ } else if (ret) {
+ DRM_DEV_ERROR(dev, "Unable to set the OPP table\n");
+ return ret;
+ } else {
/* Find the fastest defined rate */
opp = dev_pm_opp_find_freq_floor(dev, &freq);
- if (!IS_ERR(opp)) {
+
+ if (IS_ERR(opp))
+ return PTR_ERR(opp);
+ else {
gpu->fast_rate = freq;
dev_pm_opp_put(opp);
}
}
- if (!gpu->fast_rate) {
- dev_warn(dev,
- "Could not find a clock rate. Using a reasonable default\n");
- /* Pick a suitably safe clock speed for any target */
- gpu->fast_rate = 200000000;
- }
-
DBG("fast_rate=%u, slow_rate=27000000", gpu->fast_rate);
+
+ return 0;
}
int adreno_gpu_ocmem_init(struct device *dev, struct adreno_gpu *adreno_gpu,
@@ -1046,6 +1023,17 @@ int adreno_gpu_init(struct drm_device *drm, struct platform_device *pdev,
struct adreno_rev *rev = &config->rev;
const char *gpu_name;
u32 speedbin;
+ int ret;
+
+ /* This can only be done here, or devm_pm_opp_set_supported_hw will WARN_ON() */
I'd rephrase this to '...done before devm_pm_opp_of_add_table(), or
dev_pm_opp_set_config() will...'. It took me a while to find correct
limitation.
I wanted to move the code below to msm_gpu_init(), but after digging in
found that it's not possible.
+ if (IS_ERR(devm_clk_get(dev, "core"))) {
+ /*
+ * If "core" is absent, go for the legacy clock name.
+ * If we got this far in probing, it's a given one of them exists.
+ */
+ devm_pm_opp_set_clkname(dev, "core_clk");
+ } else
+ devm_pm_opp_set_clkname(dev, "core");
adreno_gpu->funcs = funcs;
adreno_gpu->info = adreno_info(config->rev);
@@ -1070,7 +1058,9 @@ int adreno_gpu_init(struct drm_device *drm, struct platform_device *pdev,
adreno_gpu_config.nr_rings = nr_rings;
- adreno_get_pwrlevels(dev, gpu);
+ ret = adreno_get_pwrlevels(dev, gpu);
+ if (ret)
+ return ret;
pm_runtime_set_autosuspend_delay(dev,
adreno_gpu->info->inactive_period);
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c
index 380249500325..cdcb00df3f25 100644
--- a/drivers/gpu/drm/msm/msm_gpu.c
+++ b/drivers/gpu/drm/msm/msm_gpu.c
@@ -59,7 +59,7 @@ static int disable_pwrrail(struct msm_gpu *gpu)
static int enable_clk(struct msm_gpu *gpu)
{
if (gpu->core_clk && gpu->fast_rate)
- clk_set_rate(gpu->core_clk, gpu->fast_rate);
+ dev_pm_opp_set_rate(&gpu->pdev->dev, gpu->fast_rate);
/* Set the RBBM timer rate to 19.2Mhz */
if (gpu->rbbmtimer_clk)
@@ -78,7 +78,7 @@ static int disable_clk(struct msm_gpu *gpu)
* will be rounded down to zero anyway so it all works out.
*/
if (gpu->core_clk)
- clk_set_rate(gpu->core_clk, 27000000);
+ dev_pm_opp_set_rate(&gpu->pdev->dev, 27000000);
if (gpu->rbbmtimer_clk)
clk_set_rate(gpu->rbbmtimer_clk, 0);
diff --git a/drivers/gpu/drm/msm/msm_gpu_devfreq.c b/drivers/gpu/drm/msm/msm_gpu_devfreq.c
index e27dbf12b5e8..ea70c1c32d94 100644
--- a/drivers/gpu/drm/msm/msm_gpu_devfreq.c
+++ b/drivers/gpu/drm/msm/msm_gpu_devfreq.c
@@ -48,7 +48,7 @@ static int msm_devfreq_target(struct device *dev, unsigned long *freq,
gpu->funcs->gpu_set_freq(gpu, opp, df->suspended);
mutex_unlock(&df->lock);
} else {
- clk_set_rate(gpu->core_clk, *freq);
+ dev_pm_opp_set_rate(dev, *freq);
}
dev_pm_opp_put(opp);
--
With best wishes
Dmitry