A recent innocuous internal optimization change in LLVM [1] causes the same issue that necessitated commit 660942f2441d ("drm: omapdrm: reduce clang stack usage") to occur in dispc_runtime_suspend() from inlinling dispc_save_context().

drivers/gpu/drm/omapdrm/dss/dispc.c:4720:27: error: stack frame size (2272) exceeds limit (2048) in 'dispc_runtime_suspend' [-Werror,-Wframe-larger-than] 4720 | static __maybe_unused int dispc_runtime_suspend(struct device *dev) | ^

There is an unfortunate interaction between the inner loops of dispc_save_context() getting unrolled and the calculation of the index into the ctx array being spilled to the stack when sanitizers are enabled [2].

While this should obviously be addressed on the LLVM side, such a fix may not be easy to craft and it is simple enough to work around the issue in the same manner as before by marking dispc_save_context() with noinline_for_stack, which makes it use the same amount of stack as dispc_restore_context() does after the same change.

Cc: stable@vger.kernel.org Link: https://github.com/llvm/llvm-project/commit/055bfc027141bbfafd51fb43f5ab81ba... [1] Link: https://llvm.org/pr143908 [2] Signed-off-by: Nathan Chancellor nathan@kernel.org --- drivers/gpu/drm/omapdrm/dss/dispc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/omapdrm/dss/dispc.c b/drivers/gpu/drm/omapdrm/dss/dispc.c index cf055815077cffad554a4ae58cfd7b81edcbb0d4..d079f557c8f24d1afd0bc182edd13165cb9c356c 100644 --- a/drivers/gpu/drm/omapdrm/dss/dispc.c +++ b/drivers/gpu/drm/omapdrm/dss/dispc.c @@ -417,7 +417,7 @@ static bool dispc_has_feature(struct dispc_device *dispc, #define RR(dispc, reg) \ dispc_write_reg(dispc, DISPC_##reg, dispc->ctx[DISPC_##reg / sizeof(u32)])

-static void dispc_save_context(struct dispc_device *dispc) +static noinline_for_stack void dispc_save_context(struct dispc_device *dispc) { int i, j;

--- base-commit: 76eeb9b8de9880ca38696b2fb56ac45ac0a25c6c change-id: 20250911-omapdrm-reduce-clang-stack-usage-pt-2-9a9ae9263b91

Best regards,