6.6-stable review patch. If anyone has any objections, please let me know.
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From: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com
[ Upstream commit 22aa1a209018dc2eca78745f7666db63637cd5dc ]
The layout of the registers {TILER,SHADER,L2}_PWROFF_LO, used to request powering off cores, is the same as the {TILER,SHADER,L2}_PWRON_LO ones: this means that in order to request poweroff of cores, we are supposed to write a bitmask of cores that should be powered off! This means that the panfrost_gpu_power_off() function has always been doing nothing.
Fix powering off the GPU by writing a bitmask of the cores to poweroff to the relevant PWROFF_LO registers and then check that the transition (from ON to OFF) has finished by polling the relevant PWRTRANS_LO registers.
While at it, in order to avoid code duplication, move the core mask logic from panfrost_gpu_power_on() to a new panfrost_get_core_mask() function, used in both poweron and poweroff.
Fixes: f3ba91228e8e ("drm/panfrost: Add initial panfrost driver") Signed-off-by: AngeloGioacchino Del Regno angelogioacchino.delregno@collabora.com Reviewed-by: Steven Price steven.price@arm.com Signed-off-by: Steven Price steven.price@arm.com Link: https://patchwork.freedesktop.org/patch/msgid/20231102141507.73481-1-angelog... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/panfrost/panfrost_gpu.c | 64 ++++++++++++++++++------- 1 file changed, 46 insertions(+), 18 deletions(-)
diff --git a/drivers/gpu/drm/panfrost/panfrost_gpu.c b/drivers/gpu/drm/panfrost/panfrost_gpu.c index d28b99732dde..e20619169fe1 100644 --- a/drivers/gpu/drm/panfrost/panfrost_gpu.c +++ b/drivers/gpu/drm/panfrost/panfrost_gpu.c @@ -321,28 +321,38 @@ static void panfrost_gpu_init_features(struct panfrost_device *pfdev) pfdev->features.shader_present, pfdev->features.l2_present); }
+static u64 panfrost_get_core_mask(struct panfrost_device *pfdev) +{ + u64 core_mask; + + if (pfdev->features.l2_present == 1) + return U64_MAX; + + /* + * Only support one core group now. + * ~(l2_present - 1) unsets all bits in l2_present except + * the bottom bit. (l2_present - 2) has all the bits in + * the first core group set. AND them together to generate + * a mask of cores in the first core group. + */ + core_mask = ~(pfdev->features.l2_present - 1) & + (pfdev->features.l2_present - 2); + dev_info_once(pfdev->dev, "using only 1st core group (%lu cores from %lu)\n", + hweight64(core_mask), + hweight64(pfdev->features.shader_present)); + + return core_mask; +} + void panfrost_gpu_power_on(struct panfrost_device *pfdev) { int ret; u32 val; - u64 core_mask = U64_MAX; + u64 core_mask;
panfrost_gpu_init_quirks(pfdev); + core_mask = panfrost_get_core_mask(pfdev);
- if (pfdev->features.l2_present != 1) { - /* - * Only support one core group now. - * ~(l2_present - 1) unsets all bits in l2_present except - * the bottom bit. (l2_present - 2) has all the bits in - * the first core group set. AND them together to generate - * a mask of cores in the first core group. - */ - core_mask = ~(pfdev->features.l2_present - 1) & - (pfdev->features.l2_present - 2); - dev_info_once(pfdev->dev, "using only 1st core group (%lu cores from %lu)\n", - hweight64(core_mask), - hweight64(pfdev->features.shader_present)); - } gpu_write(pfdev, L2_PWRON_LO, pfdev->features.l2_present & core_mask); ret = readl_relaxed_poll_timeout(pfdev->iomem + L2_READY_LO, val, val == (pfdev->features.l2_present & core_mask), @@ -367,9 +377,27 @@ void panfrost_gpu_power_on(struct panfrost_device *pfdev)
void panfrost_gpu_power_off(struct panfrost_device *pfdev) { - gpu_write(pfdev, TILER_PWROFF_LO, 0); - gpu_write(pfdev, SHADER_PWROFF_LO, 0); - gpu_write(pfdev, L2_PWROFF_LO, 0); + u64 core_mask = panfrost_get_core_mask(pfdev); + int ret; + u32 val; + + gpu_write(pfdev, SHADER_PWROFF_LO, pfdev->features.shader_present & core_mask); + ret = readl_relaxed_poll_timeout(pfdev->iomem + SHADER_PWRTRANS_LO, + val, !val, 1, 1000); + if (ret) + dev_err(pfdev->dev, "shader power transition timeout"); + + gpu_write(pfdev, TILER_PWROFF_LO, pfdev->features.tiler_present); + ret = readl_relaxed_poll_timeout(pfdev->iomem + TILER_PWRTRANS_LO, + val, !val, 1, 1000); + if (ret) + dev_err(pfdev->dev, "tiler power transition timeout"); + + gpu_write(pfdev, L2_PWROFF_LO, pfdev->features.l2_present & core_mask); + ret = readl_poll_timeout(pfdev->iomem + L2_PWRTRANS_LO, + val, !val, 0, 1000); + if (ret) + dev_err(pfdev->dev, "l2 power transition timeout"); }
int panfrost_gpu_init(struct panfrost_device *pfdev)