[PATCH 0/2] Removing dead code

[PATCH 0/2] Removing dead code

[Christian Dietrich]

Hi all!
       
        As part of the VAMOS[0] research project at the University of
Erlangen we are looking at multiple integrity errors in linux'
configuration system.

        I've been running a check on the drivers/video sourcetree for
config Items not defined in Kconfig and found 2 such cases. Sourcecode
blocks depending on these Items are not reachable from a vanilla
kernel -- dead code. I've seen such dead blocks made on purpose
e.g. while integrating new features into the kernel but generally
they're just useless.

        Each of the patches in this patchset removes on such dead
config Item, I'd be glad if you consider applying them. I've been
doing deeper analysis of such issues before and can do so again but
I'm not so sure they were fastly usefull.

        I build the patches against a vanilla kernel in order to
try if the kernel compiles with this patches

        Please keep me informed of this patch getting confirmed /
merged so we can keep track of it.

Regards

        Christian Dietrich

[0] http://vamos1.informatik.uni-erlangen.de/

Christian Dietrich (2):
  drivers/video: Removing dead FB_VIA_CAMERA config option
  drivers/video: Removing dead FB_68328_INVERT config option

 drivers/video/68328fb.c   |    4 ----
 drivers/video/via/accel.c |   16 ----------------
 include/linux/via-core.h  |    5 +----
 3 files changed, 1 insertions(+), 24 deletions(-)

[PATCH 1/2] drivers/video: Removing dead FB_VIA_CAMERA config

[Christian Dietrich]

CONFIG_FB_VIA_CAMERA doesn't exist in Kconfig, therefore removing
all references to it from the source.

Signed-off-by: Christian Dietrich <qy03fugy@stud.informatik.uni-erlangen.de>
---
 drivers/video/via/accel.c |   16 ----------------
 include/linux/via-core.h  |    5 +----
 2 files changed, 1 insertions(+), 20 deletions(-)

diff --git a/drivers/video/via/accel.c b/drivers/video/via/accel.c
index e44893e..43d4f30 100644
--- a/drivers/video/via/accel.c
+++ b/drivers/video/via/accel.c
@@ -370,22 +370,6 @@ int viafb_init_engine(struct fb_info *info)
 	viapar->shared->vq_vram_addr = viapar->fbmem_free;
 	viapar->fbmem_used += VQ_SIZE;
 
-#if defined(CONFIG_FB_VIA_CAMERA) || defined(CONFIG_FB_VIA_CAMERA_MODULE)
-	/*
-	 * Set aside a chunk of framebuffer memory for the camera
-	 * driver.  Someday this driver probably needs a proper allocator
-	 * for fbmem; for now, we just have to do this before the
-	 * framebuffer initializes itself.
-	 *
-	 * As for the size: the engine can handle three frames,
-	 * 16 bits deep, up to VGA resolution.
-	 */
-	viapar->shared->vdev->camera_fbmem_size = 3*VGA_HEIGHT*VGA_WIDTH*2;
-	viapar->fbmem_free -= viapar->shared->vdev->camera_fbmem_size;
-	viapar->fbmem_used += viapar->shared->vdev->camera_fbmem_size;
-	viapar->shared->vdev->camera_fbmem_offset = viapar->fbmem_free;
-#endif
-
 	/* Init AGP and VQ regs */
 	switch (chip_name) {
 	case UNICHROME_K8M890:
diff --git a/include/linux/via-core.h b/include/linux/via-core.h
index 7ffb521..7fc611e 100644
--- a/include/linux/via-core.h
+++ b/include/linux/via-core.h
@@ -81,10 +81,7 @@ struct viafb_dev {
 	unsigned long fbmem_start;
 	long fbmem_len;
 	void __iomem *fbmem;
-#if defined(CONFIG_FB_VIA_CAMERA) || defined(CONFIG_FB_VIA_CAMERA_MODULE)
-	long camera_fbmem_offset;
-	long camera_fbmem_size;
-#endif
+
 	/*
 	 * The MMIO region for device registers.
 	 */
-- 
1.7.0.4

Re: [PATCH 1/2] drivers/video: Removing dead FB_VIA_CAMERA config

[Jonathan Corbet]

On Mon, 23 Aug 2010 11:59:41 +0200
Christian Dietrich <qy03fugy@stud.informatik.uni-erlangen.de> wrote:

> CONFIG_FB_VIA_CAMERA doesn't exist in Kconfig, therefore removing
> all references to it from the source.

The driver using this option has been posted to the lists a few times.
I have been unforgivably slow in dealing with some review comments, and
so missed the 2.6.36 merge window.  I don't plan to let that happen
again, though.  So my preference would be to leave this code in place;
if it goes away, I'll just have to put it back.

Thanks,

jon