From efe0758081f25b39d5bb8b097fc0ae64d0e47c3f Mon Sep 17 00:00:00 2001 From: Mahantesh Kumbar Date: Mon, 14 Nov 2016 11:27:38 +0530 Subject: gpu: nvgpu: fix pmu->mscg_stat optimization issue - with help of WRITE_ONCE() & ACCESS_ONCE() make sure variable pmu->mscg_stat read/write goes through without optimization - Added WRITE_ONCE() define for kernel-3.18 version & below to support backward compatibility issue: inconsistencies on getting MSCG to trigger consistently in P5 due to a lack of memory barrier around and volatile accesses to the variable pmu->mscg_stat JIRA DNVGPU-71 Change-Id: I04d30493d42c52710304dbdfb9cb4a1e9a76f2c0 Signed-off-by: Mahantesh Kumbar Reviewed-on: http://git-master/r/1252524 (cherry picked from commit 8af7fc68e7ab06a856ba4ef4e44de7336682361b) Reviewed-on: http://git-master/r/1271614 Reviewed-by: svccoveritychecker GVS: Gerrit_Virtual_Submit Reviewed-by: Terje Bergstrom --- drivers/gpu/nvgpu/gk20a/gk20a.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'drivers/gpu/nvgpu/gk20a/gk20a.h') diff --git a/drivers/gpu/nvgpu/gk20a/gk20a.h b/drivers/gpu/nvgpu/gk20a/gk20a.h index 5e2344cf..692f054f 100644 --- a/drivers/gpu/nvgpu/gk20a/gk20a.h +++ b/drivers/gpu/nvgpu/gk20a/gk20a.h @@ -64,6 +64,10 @@ struct acr_desc; #endif #include "gm206/bios_gm206.h" +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 18, 0) +#define WRITE_ONCE(x, val) \ + x = val +#endif /* PTIMER_REF_FREQ_HZ corresponds to a period of 32 nanoseconds. 32 ns is the resolution of ptimer. */ -- cgit v1.2.2