Subject: Re: [PATCH] drm: move allocation out of drm_get_format_name()
To: Eric Engestrom <eric@engestrom.ch>, <linux-kernel@vger.kernel.org>
References: <20161105012344.GA28349@engestrom.ch>
 <20161105013325.3889-1-eric@engestrom.ch>
CC: =?UTF-8?B?VmlsbGUgU3lyasOkbMOk?= <ville.syrjala@linux.intel.com>,
        "Alex Deucher" <alexander.deucher@amd.com>,
        =?UTF-8?Q?Christian_K=c3=b6nig?= <christian.koenig@amd.com>,
        David Airlie <airlied@linux.ie>,
        Xinliang Liu <z.liuxinliang@hisilicon.com>,
        Daniel Vetter <daniel.vetter@intel.com>,
        "Jani Nikula" <jani.nikula@linux.intel.com>,
        VMware Graphics <linux-graphics-maintainer@vmware.com>,
        Sinclair Yeh <syeh@vmware.com>, "Tom St Denis" <tom.stdenis@amd.com>,
        =?UTF-8?Q?Michel_D=c3=a4nzer?= <michel.daenzer@amd.com>,
        Gustavo Padovan <gustavo.padovan@collabora.co.uk>,
        Emily Deng <Emily.Deng@amd.com>, Chunming Zhou <David1.Zhou@amd.com>,
        "Flora Cui" <Flora.Cui@amd.com>,
        Vitaly Prosyak <vitaly.prosyak@amd.com>,
        Ken Wang <Qingqing.Wang@amd.com>,
        Colin Ian King <colin.king@canonical.com>,
        "Alexandre Demers" <alexandre.f.demers@gmail.com>,
        Junwei Zhang <Jerry.Zhang@amd.com>,
        Xinwei Kong <kong.kongxinwei@hisilicon.com>,
        Chris Wilson <chris@chris-wilson.co.uk>,
        Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>,
        Wei Yongjun <yongjun_wei@trendmicro.com.cn>,
        <dri-devel@lists.freedesktop.org>, <intel-gfx@lists.freedesktop.org>
From: Thomas Hellstrom <thellstrom@vmware.com>
Message-ID: <2de17266-3532-7b13-5b35-d4cf3eaa4144@vmware.com>
Date: Sat, 5 Nov 2016 13:56:55 +0700
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For the vmwgfx part:

Acked-by: Thomas Hellstrom <thellstrom@vmware.com>


On 11/05/2016 08:33 AM, Eric Engestrom wrote:
> Fixes: 90844f00049e9f42573fd31d7c32e8fd31d3fd07
>
>     drm: make drm_get_format_name thread-safe
>
>     Signed-off-by: Eric Engestrom <eric@engestrom.ch>
>     [danvet: Clarify that the returned pointer must be freed with
>     kfree().]
>     Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>
> Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Signed-off-by: Eric Engestrom <eric@engestrom.ch>
> ---
>  drivers/gpu/drm/amd/amdgpu/dce_v10_0.c          |  7 ++---
>  drivers/gpu/drm/amd/amdgpu/dce_v11_0.c          |  7 ++---
>  drivers/gpu/drm/amd/amdgpu/dce_v6_0.c           |  3 +-
>  drivers/gpu/drm/amd/amdgpu/dce_v8_0.c           |  7 ++---
>  drivers/gpu/drm/drm_atomic.c                    |  7 +++--
>  drivers/gpu/drm/drm_crtc.c                      |  7 +++--
>  drivers/gpu/drm/drm_fourcc.c                    | 12 +++-----
>  drivers/gpu/drm/drm_framebuffer.c               |  7 +++--
>  drivers/gpu/drm/drm_modeset_helper.c            |  7 +++--
>  drivers/gpu/drm/drm_plane.c                     |  7 +++--
>  drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c |  7 ++---
>  drivers/gpu/drm/i915/i915_debugfs.c             |  8 ++---
>  drivers/gpu/drm/i915/intel_atomic_plane.c       |  8 ++---
>  drivers/gpu/drm/i915/intel_display.c            | 41 ++++++++++---------------
>  drivers/gpu/drm/radeon/atombios_crtc.c          | 14 ++++-----
>  drivers/gpu/drm/vmwgfx/vmwgfx_kms.c             |  3 +-
>  include/drm/drm_fourcc.h                        |  3 +-
>  17 files changed, 71 insertions(+), 84 deletions(-)
>
> diff --git a/include/drm/drm_fourcc.h b/include/drm/drm_fourcc.h
> index dc0aafa..5a8cb4b 100644
> --- a/include/drm/drm_fourcc.h
> +++ b/include/drm/drm_fourcc.h
> @@ -54,6 +54,7 @@ int drm_format_horz_chroma_subsampling(uint32_t format);
>  int drm_format_vert_chroma_subsampling(uint32_t format);
>  int drm_format_plane_width(int width, uint32_t format, int plane);
>  int drm_format_plane_height(int height, uint32_t format, int plane);
> -char *drm_get_format_name(uint32_t format) __malloc;
> +typedef char drm_format_name_buf[32];
> +char *drm_get_format_name(uint32_t format, drm_format_name_buf buf);
>  
>  #endif /* __DRM_FOURCC_H__ */
> diff --git a/drivers/gpu/drm/drm_fourcc.c b/drivers/gpu/drm/drm_fourcc.c
> index cbb8b77..34ed520 100644
> --- a/drivers/gpu/drm/drm_fourcc.c
> +++ b/drivers/gpu/drm/drm_fourcc.c
> @@ -79,17 +79,13 @@ uint32_t drm_mode_legacy_fb_format(uint32_t bpp, uint32_t depth)
>  EXPORT_SYMBOL(drm_mode_legacy_fb_format);
>  
>  /**
> - * drm_get_format_name - return a string for drm fourcc format
> + * drm_get_format_name - fill a string with a drm fourcc format's name
>   * @format: format to compute name of
> + * @buf: caller-supplied buffer
> - *
> - * Note that the buffer returned by this function is owned by the caller
> - * and will need to be freed using kfree().
>   */
> -char *drm_get_format_name(uint32_t format)
> +char *drm_get_format_name(uint32_t format, drm_format_name_buf buf)
>  {
> -	char *buf = kmalloc(32, GFP_KERNEL);
> -
> -	snprintf(buf, 32,
> +	snprintf(buf, sizeof(drm_format_name_buf),
>  		 "%c%c%c%c %s-endian (0x%08x)",
>  		 printable_char(format & 0xff),
>  		 printable_char((format >> 8) & 0xff),
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> index 199d3f7..cefa3d8 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v10_0.c
> @@ -2032,7 +2032,7 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
>  	u32 tmp, viewport_w, viewport_h;
>  	int r;
>  	bool bypass_lut = false;
> -	char *format_name;
> +	drm_format_name_buf format_name;
>  
>  	/* no fb bound */
>  	if (!atomic && !crtc->primary->fb) {
> @@ -2144,9 +2144,8 @@ static int dce_v10_0_crtc_do_set_base(struct drm_crtc *crtc,
>  		bypass_lut = true;
>  		break;
>  	default:
> -		format_name = drm_get_format_name(target_fb->pixel_format);
> -		DRM_ERROR("Unsupported screen format %s\n", format_name);
> -		kfree(format_name);
> +		DRM_ERROR("Unsupported screen format %s\n",
> +		          drm_get_format_name(target_fb->pixel_format, format_name));
>  		return -EINVAL;
>  	}
>  
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> index ecd000e..462abb8 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v11_0.c
> @@ -2013,7 +2013,7 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
>  	u32 tmp, viewport_w, viewport_h;
>  	int r;
>  	bool bypass_lut = false;
> -	char *format_name;
> +	drm_format_name_buf format_name;
>  
>  	/* no fb bound */
>  	if (!atomic && !crtc->primary->fb) {
> @@ -2125,9 +2125,8 @@ static int dce_v11_0_crtc_do_set_base(struct drm_crtc *crtc,
>  		bypass_lut = true;
>  		break;
>  	default:
> -		format_name = drm_get_format_name(target_fb->pixel_format);
> -		DRM_ERROR("Unsupported screen format %s\n", format_name);
> -		kfree(format_name);
> +		DRM_ERROR("Unsupported screen format %s\n",
> +		          drm_get_format_name(target_fb->pixel_format, format_name));
>  		return -EINVAL;
>  	}
>  
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> index 44547f9..3b8cea3 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v6_0.c
> @@ -1456,6 +1456,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
>  	u32 viewport_w, viewport_h;
>  	int r;
>  	bool bypass_lut = false;
> +	drm_format_name_buf format_name;
>  
>  	/* no fb bound */
>  	if (!atomic && !crtc->primary->fb) {
> @@ -1559,7 +1560,7 @@ static int dce_v6_0_crtc_do_set_base(struct drm_crtc *crtc,
>  		break;
>  	default:
>  		DRM_ERROR("Unsupported screen format %s\n",
> -			  drm_get_format_name(target_fb->pixel_format));
> +		          drm_get_format_name(target_fb->pixel_format, format_name));
>  		return -EINVAL;
>  	}
>  
> diff --git a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> index 979aedf..8c624b5 100644
> --- a/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> +++ b/drivers/gpu/drm/amd/amdgpu/dce_v8_0.c
> @@ -1910,7 +1910,7 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
>  	u32 viewport_w, viewport_h;
>  	int r;
>  	bool bypass_lut = false;
> -	char *format_name;
> +	drm_format_name_buf format_name;
>  
>  	/* no fb bound */
>  	if (!atomic && !crtc->primary->fb) {
> @@ -2015,9 +2015,8 @@ static int dce_v8_0_crtc_do_set_base(struct drm_crtc *crtc,
>  		bypass_lut = true;
>  		break;
>  	default:
> -		format_name = drm_get_format_name(target_fb->pixel_format);
> -		DRM_ERROR("Unsupported screen format %s\n", format_name);
> -		kfree(format_name);
> +		DRM_ERROR("Unsupported screen format %s\n",
> +		          drm_get_format_name(target_fb->pixel_format, format_name));
>  		return -EINVAL;
>  	}
>  
> diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> index c32fb3c..8d2e6a5 100644
> --- a/drivers/gpu/drm/drm_atomic.c
> +++ b/drivers/gpu/drm/drm_atomic.c
> @@ -835,9 +835,10 @@ static int drm_atomic_plane_check(struct drm_plane *plane,
>  	/* Check whether this plane supports the fb pixel format. */
>  	ret = drm_plane_check_pixel_format(plane, state->fb->pixel_format);
>  	if (ret) {
> -		char *format_name = drm_get_format_name(state->fb->pixel_format);
> -		DRM_DEBUG_ATOMIC("Invalid pixel format %s\n", format_name);
> -		kfree(format_name);
> +		drm_format_name_buf format_name;
> +		DRM_DEBUG_ATOMIC("Invalid pixel format %s\n",
> +		                 drm_get_format_name(state->fb->pixel_format,
> +		                                     format_name));
>  		return ret;
>  	}
>  
> diff --git a/drivers/gpu/drm/drm_crtc.c b/drivers/gpu/drm/drm_crtc.c
> index 13441e2..7f5bbe3 100644
> --- a/drivers/gpu/drm/drm_crtc.c
> +++ b/drivers/gpu/drm/drm_crtc.c
> @@ -827,9 +827,10 @@ int drm_mode_setcrtc(struct drm_device *dev, void *data,
>  			ret = drm_plane_check_pixel_format(crtc->primary,
>  							   fb->pixel_format);
>  			if (ret) {
> -				char *format_name = drm_get_format_name(fb->pixel_format);
> -				DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
> -				kfree(format_name);
> +				drm_format_name_buf format_name;
> +				DRM_DEBUG_KMS("Invalid pixel format %s\n",
> +				              drm_get_format_name(fb->pixel_format,
> +				                                  format_name));
>  				goto out;
>  			}
>  		}
> diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
> index 49fd7db..12ad188 100644
> --- a/drivers/gpu/drm/drm_framebuffer.c
> +++ b/drivers/gpu/drm/drm_framebuffer.c
> @@ -133,9 +133,10 @@ static int framebuffer_check(const struct drm_mode_fb_cmd2 *r)
>  
>  	info = __drm_format_info(r->pixel_format & ~DRM_FORMAT_BIG_ENDIAN);
>  	if (!info) {
> -		char *format_name = drm_get_format_name(r->pixel_format);
> -		DRM_DEBUG_KMS("bad framebuffer format %s\n", format_name);
> -		kfree(format_name);
> +		drm_format_name_buf format_name;
> +		DRM_DEBUG_KMS("bad framebuffer format %s\n",
> +		              drm_get_format_name(r->pixel_format,
> +		                                  format_name));
>  		return -EINVAL;
>  	}
>  
> diff --git a/drivers/gpu/drm/drm_modeset_helper.c b/drivers/gpu/drm/drm_modeset_helper.c
> index 2544dfe..b6ab72a 100644
> --- a/drivers/gpu/drm/drm_modeset_helper.c
> +++ b/drivers/gpu/drm/drm_modeset_helper.c
> @@ -75,10 +75,11 @@ void drm_helper_mode_fill_fb_struct(struct drm_framebuffer *fb,
>  
>  	info = drm_format_info(mode_cmd->pixel_format);
>  	if (!info || !info->depth) {
> -		char *format_name = drm_get_format_name(mode_cmd->pixel_format);
> +		drm_format_name_buf format_name;
>  
> -		DRM_DEBUG_KMS("non-RGB pixel format %s\n", format_name);
> -		kfree(format_name);
> +		DRM_DEBUG_KMS("non-RGB pixel format %s\n",
> +		              drm_get_format_name(mode_cmd->pixel_format,
> +		                                  format_name));
>  
>  		fb->depth = 0;
>  		fb->bits_per_pixel = 0;
> diff --git a/drivers/gpu/drm/drm_plane.c b/drivers/gpu/drm/drm_plane.c
> index 249c0ae..9a45c52 100644
> --- a/drivers/gpu/drm/drm_plane.c
> +++ b/drivers/gpu/drm/drm_plane.c
> @@ -479,9 +479,10 @@ static int __setplane_internal(struct drm_plane *plane,
>  	/* Check whether this plane supports the fb pixel format. */
>  	ret = drm_plane_check_pixel_format(plane, fb->pixel_format);
>  	if (ret) {
> -		char *format_name = drm_get_format_name(fb->pixel_format);
> -		DRM_DEBUG_KMS("Invalid pixel format %s\n", format_name);
> -		kfree(format_name);
> +		drm_format_name_buf format_name;
> +		DRM_DEBUG_KMS("Invalid pixel format %s\n",
> +		              drm_get_format_name(fb->pixel_format,
> +		                                  format_name));
>  		goto out;
>  	}
>  
> diff --git a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> index 7e7a4d4..c5c0b38 100644
> --- a/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> +++ b/drivers/gpu/drm/hisilicon/kirin/kirin_drm_ade.c
> @@ -608,17 +608,16 @@ static void ade_rdma_set(void __iomem *base, struct drm_framebuffer *fb,
>  			 u32 ch, u32 y, u32 in_h, u32 fmt)
>  {
>  	struct drm_gem_cma_object *obj = drm_fb_cma_get_gem_obj(fb, 0);
> -	char *format_name;
> +	drm_format_name_buf format_name;
>  	u32 reg_ctrl, reg_addr, reg_size, reg_stride, reg_space, reg_en;
>  	u32 stride = fb->pitches[0];
>  	u32 addr = (u32)obj->paddr + y * stride;
>  
>  	DRM_DEBUG_DRIVER("rdma%d: (y=%d, height=%d), stride=%d, paddr=0x%x\n",
>  			 ch + 1, y, in_h, stride, (u32)obj->paddr);
> -	format_name = drm_get_format_name(fb->pixel_format);
>  	DRM_DEBUG_DRIVER("addr=0x%x, fb:%dx%d, pixel_format=%d(%s)\n",
> -			 addr, fb->width, fb->height, fmt, format_name);
> +			 addr, fb->width, fb->height, fmt,
> +			 drm_get_format_name(fb->pixel_format, format_name));
> -	kfree(format_name);
>  
>  	/* get reg offset */
>  	reg_ctrl = RD_CH_CTRL(ch);
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 20638d2..39f76b1 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2971,7 +2971,7 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
>  	for_each_intel_plane_on_crtc(dev, intel_crtc, intel_plane) {
>  		struct drm_plane_state *state;
>  		struct drm_plane *plane = &intel_plane->base;
> -		char *format_name;
> +		drm_format_name_buf format_name;
>  
>  		if (!plane->state) {
>  			seq_puts(m, "plane->state is NULL!\n");
> @@ -2981,9 +2981,9 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
>  		state = plane->state;
>  
>  		if (state->fb) {
> -			format_name = drm_get_format_name(state->fb->pixel_format);
> +			drm_get_format_name(state->fb->pixel_format, format_name);
>  		} else {
> -			format_name = kstrdup("N/A", GFP_KERNEL);
> +			sprintf(format_name, "N/A");
>  		}
>  
>  		seq_printf(m, "\t--Plane id %d: type=%s, crtc_pos=%4dx%4d, crtc_size=%4dx%4d, src_pos=%d.%04ux%d.%04u, src_size=%d.%04ux%d.%04u, format=%s, rotation=%s\n",
> @@ -3001,8 +3001,6 @@ static void intel_plane_info(struct seq_file *m, struct intel_crtc *intel_crtc)
>  			   ((state->src_h & 0xffff) * 15625) >> 10,
>  			   format_name,
>  			   plane_rotation(state->rotation));
> -
> -		kfree(format_name);
>  	}
>  }
>  
> diff --git a/drivers/gpu/drm/i915/intel_atomic_plane.c b/drivers/gpu/drm/i915/intel_atomic_plane.c
> index c762ae5..289ebc9 100644
> --- a/drivers/gpu/drm/i915/intel_atomic_plane.c
> +++ b/drivers/gpu/drm/i915/intel_atomic_plane.c
> @@ -143,7 +143,7 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
>  		crtc_state->base.enable ? crtc_state->pipe_src_h : 0;
>  
>  	if (state->fb && drm_rotation_90_or_270(state->rotation)) {
> -		char *format_name;
> +		drm_format_name_buf format_name;
>  
>  		if (!(state->fb->modifier[0] == I915_FORMAT_MOD_Y_TILED ||
>  			state->fb->modifier[0] == I915_FORMAT_MOD_Yf_TILED)) {
> @@ -159,9 +159,9 @@ static int intel_plane_atomic_check(struct drm_plane *plane,
>  		switch (state->fb->pixel_format) {
>  		case DRM_FORMAT_C8:
>  		case DRM_FORMAT_RGB565:
> -			format_name = drm_get_format_name(state->fb->pixel_format);
> -			DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n", format_name);
> -			kfree(format_name);
> +			DRM_DEBUG_KMS("Unsupported pixel format %s for 90/270!\n",
> +			              drm_get_format_name(state->fb->pixel_format,
> +			                                  format_name));
>  			return -EINVAL;
>  
>  		default:
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 6f8f6ec..ab0882f 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -12871,7 +12871,7 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
>  
>  	DRM_DEBUG_KMS("planes on this crtc\n");
>  	list_for_each_entry(plane, &dev->mode_config.plane_list, head) {
> -		char *format_name;
> +		drm_format_name_buf format_name;
>  		intel_plane = to_intel_plane(plane);
>  		if (intel_plane->pipe != crtc->pipe)
>  			continue;
> @@ -12884,12 +12884,11 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
>  			continue;
>  		}
>  
> -		format_name = drm_get_format_name(fb->pixel_format);
> -
>  		DRM_DEBUG_KMS("[PLANE:%d:%s] enabled",
>  			      plane->base.id, plane->name);
>  		DRM_DEBUG_KMS("\tFB:%d, fb = %ux%u format = %s",
> -			      fb->base.id, fb->width, fb->height, format_name);
> +			      fb->base.id, fb->width, fb->height,
> +			      drm_get_format_name(fb->pixel_format, format_name));
>  		DRM_DEBUG_KMS("\tscaler:%d src %dx%d+%d+%d dst %dx%d+%d+%d\n",
>  			      state->scaler_id,
>  			      state->base.src.x1 >> 16,
> @@ -12899,8 +12898,6 @@ static void intel_dump_pipe_config(struct intel_crtc *crtc,
>  			      state->base.dst.x1, state->base.dst.y1,
>  			      drm_rect_width(&state->base.dst),
>  			      drm_rect_height(&state->base.dst));
> -
> -		kfree(format_name);
>  	}
>  }
>  
> @@ -15749,7 +15746,7 @@ static int intel_framebuffer_init(struct drm_device *dev,
>  	unsigned int tiling = i915_gem_object_get_tiling(obj);
>  	int ret;
>  	u32 pitch_limit, stride_alignment;
> -	char *format_name;
> +	drm_format_name_buf format_name;
>  
>  	WARN_ON(!mutex_is_locked(&dev->struct_mutex));
>  
> @@ -15840,18 +15837,16 @@ static int intel_framebuffer_init(struct drm_device *dev,
>  		break;
>  	case DRM_FORMAT_XRGB1555:
>  		if (INTEL_INFO(dev)->gen > 3) {
> -			format_name = drm_get_format_name(mode_cmd->pixel_format);
> -			DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> -			kfree(format_name);
> +			DRM_DEBUG("unsupported pixel format: %s\n",
> +			          drm_get_format_name(mode_cmd->pixel_format, format_name));
>  			return -EINVAL;
>  		}
>  		break;
>  	case DRM_FORMAT_ABGR8888:
>  		if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv) &&
>  		    INTEL_INFO(dev)->gen < 9) {
> -			format_name = drm_get_format_name(mode_cmd->pixel_format);
> -			DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> -			kfree(format_name);
> +			DRM_DEBUG("unsupported pixel format: %s\n",
> +			          drm_get_format_name(mode_cmd->pixel_format, format_name));
>  			return -EINVAL;
>  		}
>  		break;
> @@ -15859,17 +15854,15 @@ static int intel_framebuffer_init(struct drm_device *dev,
>  	case DRM_FORMAT_XRGB2101010:
>  	case DRM_FORMAT_XBGR2101010:
>  		if (INTEL_INFO(dev)->gen < 4) {
> -			format_name = drm_get_format_name(mode_cmd->pixel_format);
> -			DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> -			kfree(format_name);
> +			DRM_DEBUG("unsupported pixel format: %s\n",
> +			          drm_get_format_name(mode_cmd->pixel_format, format_name));
>  			return -EINVAL;
>  		}
>  		break;
>  	case DRM_FORMAT_ABGR2101010:
>  		if (!IS_VALLEYVIEW(dev_priv) && !IS_CHERRYVIEW(dev_priv)) {
> -			format_name = drm_get_format_name(mode_cmd->pixel_format);
> -			DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> -			kfree(format_name);
> +			DRM_DEBUG("unsupported pixel format: %s\n",
> +			          drm_get_format_name(mode_cmd->pixel_format, format_name));
>  			return -EINVAL;
>  		}
>  		break;
> @@ -15878,16 +15871,14 @@ static int intel_framebuffer_init(struct drm_device *dev,
>  	case DRM_FORMAT_YVYU:
>  	case DRM_FORMAT_VYUY:
>  		if (INTEL_INFO(dev)->gen < 5) {
> -			format_name = drm_get_format_name(mode_cmd->pixel_format);
> -			DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> -			kfree(format_name);
> +			DRM_DEBUG("unsupported pixel format: %s\n",
> +			          drm_get_format_name(mode_cmd->pixel_format, format_name));
>  			return -EINVAL;
>  		}
>  		break;
>  	default:
> -		format_name = drm_get_format_name(mode_cmd->pixel_format);
> -		DRM_DEBUG("unsupported pixel format: %s\n", format_name);
> -		kfree(format_name);
> +		DRM_DEBUG("unsupported pixel format: %s\n",
> +		          drm_get_format_name(mode_cmd->pixel_format, format_name));
>  		return -EINVAL;
>  	}
>  
> diff --git a/drivers/gpu/drm/radeon/atombios_crtc.c b/drivers/gpu/drm/radeon/atombios_crtc.c
> index 74f99ba..adff13b 100644
> --- a/drivers/gpu/drm/radeon/atombios_crtc.c
> +++ b/drivers/gpu/drm/radeon/atombios_crtc.c
> @@ -1156,7 +1156,7 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
>  	u32 tmp, viewport_w, viewport_h;
>  	int r;
>  	bool bypass_lut = false;
> -	char *format_name;
> +	drm_format_name_buf format_name;
>  
>  	/* no fb bound */
>  	if (!atomic && !crtc->primary->fb) {
> @@ -1260,9 +1260,8 @@ static int dce4_crtc_do_set_base(struct drm_crtc *crtc,
>  		bypass_lut = true;
>  		break;
>  	default:
> -		format_name = drm_get_format_name(target_fb->pixel_format);
> -		DRM_ERROR("Unsupported screen format %s\n", format_name);
> -		kfree(format_name);
> +		DRM_ERROR("Unsupported screen format %s\n",
> +		          drm_get_format_name(target_fb->pixel_format, format_name));
>  		return -EINVAL;
>  	}
>  
> @@ -1473,7 +1472,7 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
>  	u32 viewport_w, viewport_h;
>  	int r;
>  	bool bypass_lut = false;
> -	char *format_name;
> +	drm_format_name_buf format_name;
>  
>  	/* no fb bound */
>  	if (!atomic && !crtc->primary->fb) {
> @@ -1563,9 +1562,8 @@ static int avivo_crtc_do_set_base(struct drm_crtc *crtc,
>  		bypass_lut = true;
>  		break;
>  	default:
> -		format_name = drm_get_format_name(target_fb->pixel_format);
> -		DRM_ERROR("Unsupported screen format %s\n", format_name);
> -		kfree(format_name);
> +		DRM_ERROR("Unsupported screen format %s\n",
> +		          drm_get_format_name(target_fb->pixel_format, format_name));
>  		return -EINVAL;
>  	}
>  
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> index c965514..7376307 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> @@ -985,8 +985,9 @@ static struct drm_framebuffer *vmw_kms_fb_create(struct drm_device *dev,
>  
>  	info = drm_format_info(mode_cmd2->pixel_format);
>  	if (!info || !info->depth) {
> +		drm_format_name_buf format_name;
>  		DRM_ERROR("Unsupported framebuffer format %s\n",
> -			  drm_get_format_name(mode_cmd2->pixel_format));
> +		          drm_get_format_name(mode_cmd2->pixel_format, format_name));
>  		return ERR_PTR(-EINVAL);
>  	}
>