[bug report] drm: atmel-hlcdc: add driver ops to differentiate HLCDC and XLCDC IP

[Manikandan.M at microchip.com]

Hi Dan,

Thank you for reporting the bug.I will prepare and send a fix-up patch soon.

On 20/06/24 2:20 pm, Dan Carpenter wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> Hello Manikandan Muralidharan,
> 
> Commit aa71584b323a ("drm: atmel-hlcdc: add driver ops to
> differentiate HLCDC and XLCDC IP") from Apr 24, 2024 (linux-next),
> leads to the following Smatch static checker warning:
> 
>          drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c:573 atmel_hlcdc_plane_update_buffers()
>          error: uninitialized symbol 'sr'.
> 
> drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c
>      556 static void atmel_hlcdc_plane_update_buffers(struct atmel_hlcdc_plane *plane,
>      557                                              struct atmel_hlcdc_plane_state *state)
>      558 {
>      559         const struct atmel_hlcdc_layer_desc *desc = plane->layer.desc;
>      560         struct atmel_hlcdc_dc *dc = plane->base.dev->dev_private;
>      561         struct drm_framebuffer *fb = state->base.fb;
>      562         u32 sr;
>      563         int i;
>      564
>      565         if (!dc->desc->is_xlcdc)
>      566                 sr = atmel_hlcdc_layer_read_reg(&plane->layer, ATMEL_HLCDC_LAYER_CHSR);
> 
> sr is uninitialized on else path.
> 
>      567
>      568         for (i = 0; i < state->nplanes; i++) {
>      569                 struct drm_gem_dma_object *gem = drm_fb_dma_get_gem_obj(fb, i);
>      570
>      571                 state->dscrs[i]->addr = gem->dma_addr + state->offsets[i];
>      572
> --> 573                 dc->desc->ops->lcdc_update_buffers(plane, state, sr, i);
>                                                                           ^^
> Uninitialized.
> 
>      574
>      575                 if (desc->layout.xstride[i])
>      576                         atmel_hlcdc_layer_write_cfg(&plane->layer,
>      577                                                     desc->layout.xstride[i],
>      578                                                     state->xstride[i]);
>      579
>      580                 if (desc->layout.pstride[i])
>      581                         atmel_hlcdc_layer_write_cfg(&plane->layer,
>      582                                                     desc->layout.pstride[i],
>      583                                                     state->pstride[i]);
>      584         }
>      585 }
> 
> regards,
> dan carpenter

-- 
Thanks and Regards,
Manikandan M.