From 85c323c3e89d6e1b624b839c3325ae072952e545 Mon Sep 17 00:00:00 2001 From: Debarshi Dutta Date: Wed, 8 Aug 2018 17:36:01 +0530 Subject: gpu: nvgpu: restrict devfreq during active clk_arb set requests Restrict access to devfreq when there are active set requests in the clk_arbiter. We make the following changes in the patch. 1) Add a global counter in the struct gk20a named clk_arb_global_nr which is used to track the number of active set requests in the system. 2) Anytime a set request is successfully made by the userspace, clk_arb_global_nr is incremented by 1 and during the completion of request(releasing the corresponding file handle), clk_arb_global_nr is decremented by 1. 3) gk20a_scale_target(invoked by devfreq to set the new frequency based on load) atomically checks clk_arb_global_nr. If the value = 0, the code simply continue or else if its > 0, it quits thus making devfreq requests mutually exclusive with the clk_arbiter. Bug 2061372 Change-Id: I5d19de03e45520f4ff8fccb97b1f1589d04c8ab8 Signed-off-by: Debarshi Dutta Reviewed-on: https://git-master.nvidia.com/r/1790002 Reviewed-by: mobile promotions Tested-by: mobile promotions --- drivers/gpu/nvgpu/clk/clk_arb.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) (limited to 'drivers/gpu/nvgpu/clk') diff --git a/drivers/gpu/nvgpu/clk/clk_arb.c b/drivers/gpu/nvgpu/clk/clk_arb.c index 452d9de3..3d97535d 100644 --- a/drivers/gpu/nvgpu/clk/clk_arb.c +++ b/drivers/gpu/nvgpu/clk/clk_arb.c @@ -772,6 +772,11 @@ int nvgpu_clk_arb_init_arbiter(struct gk20a *g) return err; } +bool nvgpu_clk_arb_has_active_req(struct gk20a *g) +{ + return (nvgpu_atomic_read(&g->clk_arb_global_nr) > 0); +} + void nvgpu_clk_arb_send_thermal_alarm(struct gk20a *g) { nvgpu_clk_arb_schedule_alarm(g, @@ -854,10 +859,12 @@ void nvgpu_clk_arb_free_fd(struct nvgpu_ref *refcount) struct nvgpu_clk_dev *dev = container_of(refcount, struct nvgpu_clk_dev, refcount); struct nvgpu_clk_session *session = dev->session; + struct gk20a *g = session->g; - nvgpu_clk_notification_queue_free(session->g, &dev->queue); + nvgpu_clk_notification_queue_free(g, &dev->queue); - nvgpu_kfree(session->g, dev); + nvgpu_atomic_dec(&g->clk_arb_global_nr); + nvgpu_kfree(g, dev); } void nvgpu_clk_arb_free_session(struct nvgpu_ref *refcount) -- cgit v1.2.2