Re: [PATCH][next] drm/nouveau: Avoid -Wflex-array-member-not-at-end warning

[Danilo Krummrich]

On 9/13/24 12:23 PM, Danilo Krummrich wrote:

Hi,

On 9/13/24 10:09 AM, Gustavo A. R. Silva wrote:

Hi all,

Friendly ping: who can take this, please? 🙂

Usually, that's me. But I thought you might want to send a v2 based on Kees'
comments?

Do you plan to follow up on this? I'd prefer if we could get rid of the open-
coded "17". So, maybe just go with the define until we have something like
STACK_FLEX_COUNT()?

- Danilo

Thanks
-Gustavo

On 21/08/24 22:16, Gustavo A. R. Silva wrote:

Use the `DEFINE_RAW_FLEX()` helper for an on-stack definition of
a flexible structure where the size of the flexible-array member
is known at compile-time, and refactor the rest of the code,
accordingly.

So, with this, fix the following warning:

drivers/gpu/drm/nouveau/dispnv50/disp.c:779:47: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array- member-not-at-end]

Signed-off-by: Gustavo A. R. Silva <gustavo...@kernel.org>
---
  drivers/gpu/drm/nouveau/dispnv50/disp.c | 20 +++++++++-----------
  1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/ nouveau/dispnv50/disp.c

index eed579a6c858..ddddc69640be 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c

@@ -774,11 +774,9 @@ nv50_hdmi_enable(struct drm_encoder *encoder, struct nouveau_crtc *nv_crtc,

      struct drm_hdmi_info *hdmi = &nv_connector->base.display_info.hdmi;
      union hdmi_infoframe infoframe = { 0 };
      const u8 rekey = 56; /* binary driver, and tegra, constant */
+    DEFINE_RAW_FLEX(struct nvif_outp_infoframe_v0, args, data, 17);
+    const u8 data_len = 17; /* same length as in DEFINE_RAW_FLEX above. */
      u32 max_ac_packet;
-    struct {
-        struct nvif_outp_infoframe_v0 infoframe;
-        u8 data[17];
-    } args = { 0 };
      int ret, size;
      max_ac_packet  = mode->htotal - mode->hdisplay;

@@ -815,29 +813,29 @@ nv50_hdmi_enable(struct drm_encoder *encoder, struct nouveau_crtc *nv_crtc,

          return;
      /* AVI InfoFrame. */
-    args.infoframe.version = 0;
-    args.infoframe.head = nv_crtc->index;
+    args->version = 0;
+    args->head = nv_crtc->index;

      if (!drm_hdmi_avi_infoframe_from_display_mode(&infoframe.avi, &nv_connector->base, mode)) {           drm_hdmi_avi_infoframe_quant_range(&infoframe.avi, &nv_connector- >base, mode,

                             HDMI_QUANTIZATION_RANGE_FULL);

-        size = hdmi_infoframe_pack(&infoframe, args.data, ARRAY_SIZE(args.data));

+        size = hdmi_infoframe_pack(&infoframe, args->data, data_len);
      } else {
          size = 0;
      }

-    nvif_outp_infoframe(&nv_encoder->outp, NVIF_OUTP_INFOFRAME_V0_AVI, &args.infoframe, size); +    nvif_outp_infoframe(&nv_encoder->outp, NVIF_OUTP_INFOFRAME_V0_AVI, args, size);

      /* Vendor InfoFrame. */
-    memset(&args.data, 0, sizeof(args.data));
+    memset(args->data, 0, data_len);
      if (!drm_hdmi_vendor_infoframe_from_display_mode(&infoframe.vendor.hdmi,
                               &nv_connector->base, mode))

-        size = hdmi_infoframe_pack(&infoframe, args.data, ARRAY_SIZE(args.data));

+        size = hdmi_infoframe_pack(&infoframe, args->data, data_len);
      else
          size = 0;

-    nvif_outp_infoframe(&nv_encoder->outp, NVIF_OUTP_INFOFRAME_V0_VSI, &args.infoframe, size); +    nvif_outp_infoframe(&nv_encoder->outp, NVIF_OUTP_INFOFRAME_V0_VSI, args, size);

      nv_encoder->hdmi.enabled = true;
  }