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/os/linux/debug_clk_gm20b.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/gpu/nvgpu/os/linux/debug_clk_gm20b.c') diff --git a/drivers/gpu/nvgpu/os/linux/debug_clk_gm20b.c b/drivers/gpu/nvgpu/os/linux/debug_clk_gm20b.c index 52eea83f..b8b95fd7 100644 --- a/drivers/gpu/nvgpu/os/linux/debug_clk_gm20b.c +++ b/drivers/gpu/nvgpu/os/linux/debug_clk_gm20b.c @@ -17,6 +17,7 @@ #include #include +#include #include "gm20b/clk_gm20b.h" #include "os_linux.h" @@ -33,6 +34,8 @@ static int rate_get(void *data, u64 *val) static int rate_set(void *data, u64 val) { struct gk20a *g = (struct gk20a *)data; + if (nvgpu_clk_arb_has_active_req(g)) + return 0; return g->ops.clk.set_rate(g, CTRL_CLK_DOMAIN_GPCCLK, (u32)val); } DEFINE_SIMPLE_ATTRIBUTE(rate_fops, rate_get, rate_set, "%llu\n"); -- cgit v1.2.2