Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1339107 > unrolled thread

[PATCH 0/3] video/fbdev: avoid module usage in non-modular sparc code

Back to article view | Back to linux.kernel

Contents

  [PATCH 0/3] video/fbdev: avoid module usage in non-modular sparc code Paul Gortmaker <paul.gortmaker@windriver.com> - 2016-02-22 04:20 +0100
    [PATCH 1/3] drivers/video: make fbdev/sunxvr500.c explicitly non-modular Paul Gortmaker <paul.gortmaker@windriver.com> - 2016-02-22 04:20 +0100

#1339107 — [PATCH 0/3] video/fbdev: avoid module usage in non-modular sparc code

This series of commits is a part of a larger project to ensure
people don't reference modular support functions in non-modular
code.  Overall there was roughly 5k lines of dead code in the
kernel due to this.  So far we've fixed several areas, like tty,
x86, net, ... and we continue to work on other areas.

There are several reasons to not use module support for code that
can never be built as a module, but the big ones are:

 (1) it is easy to accidentally write unused module_exit and remove code
 (2) it can be misleading when reading the source, thinking it can be
     modular when the Makefile and/or Kconfig prohibit it
 (3) it requires the include of the module.h header file which in turn
     includes nearly everything else, thus adding to CPP overhead.
 (4) it gets copied/replicated into other code and spreads like weeds.

For the video fb subsystem, I have about 40 commits in my personal
testing queue, but rather than overwhelm maintainers with a large
patch series, I'm looking for subsets within that to keep the Cc on
the series and the 00/N boiler-plate to a sane amount.

To that end, the sparc specific fb drivers is a nice small subset
that can be used to test the waters in the video subsystem, to ensure
the overall goals here are OK with everyone maintaining fb code.

The disallow of unbind might seem like overkill, but for drivers that
had a ".remove" function, it is the only way we can block people from
abusing existing infrastructure in order to continue getting at that
otherwise dead function call that we want to remove.

We toss out a net amount of about 80 lines of dead code here in just
three commits; not groundbreaking, but a step in the right direction.

Build tested for sparc64, allmodconfig; but with CONFIG_FB=y as the
drivers here all depend on this specific value to get enabled.

Paul.
---

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: linux-fbdev@vger.kernel.org
Cc: sparclinux@vger.kernel.org

Paul Gortmaker (3):
  drivers/video: make fbdev/sunxvr500.c explicitly non-modular
  drivers/video: make fbdev/sunxvr1000.c explicitly non-modular
  drivers/video: make fbdev/sunxvr2500.c explicitly non-modular

 drivers/video/fbdev/sunxvr1000.c | 42 +++++++---------------------------------
 drivers/video/fbdev/sunxvr2500.c | 39 +++++++------------------------------
 drivers/video/fbdev/sunxvr500.c  | 42 +++++++---------------------------------
 3 files changed, 21 insertions(+), 102 deletions(-)

-- 
2.6.1

[toc] | [next] | [standalone]

#1339112 — [PATCH 1/3] drivers/video: make fbdev/sunxvr500.c explicitly non-modular

The Kconfig currently controlling compilation of this code is:

config FB_XVR500
        bool "Sun XVR-500 3DLABS Wildcat support"

...meaning that it currently is not being built as a module by anyone.
Lets remove the modular code that is essentially orphaned, so that
when reading the driver there is no doubt it is builtin-only.

We explicitly disallow a driver unbind, since that doesn't have a
sensible use case anyway, and it allows us to drop the ".remove"
code for non-modular drivers.

Since module_init translates to device_initcall in the non-modular
case, the init ordering remains unchanged with this commit.

We don't replace module.h with init.h since the file already has that.

We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.

Cc: Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: sparclinux@vger.kernel.org
Cc: linux-fbdev@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
 drivers/video/fbdev/sunxvr500.c | 42 +++++++----------------------------------
 1 file changed, 7 insertions(+), 35 deletions(-)

diff --git a/drivers/video/fbdev/sunxvr500.c b/drivers/video/fbdev/sunxvr500.c
index 387350d004df..dc0d886e4e7e 100644
--- a/drivers/video/fbdev/sunxvr500.c
+++ b/drivers/video/fbdev/sunxvr500.c
@@ -1,9 +1,10 @@
-/* sunxvr500.c: Sun 3DLABS XVR-500 Expert3D driver for sparc64 systems
+/* sunxvr500.c: Sun 3DLABS XVR-500 Expert3D fb driver for sparc64 systems
+ *
+ * License: GPL
  *
  * Copyright (C) 2007 David S. Miller (davem@davemloft.net)
  */
 
-#include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/fb.h>
 #include <linux/pci.h>
@@ -392,25 +393,6 @@ err_out:
 	return err;
 }
 
-static void e3d_pci_unregister(struct pci_dev *pdev)
-{
-	struct fb_info *info = pci_get_drvdata(pdev);
-	struct e3d_info *ep = info->par;
-
-	unregister_framebuffer(info);
-
-	iounmap(ep->ramdac);
-	iounmap(ep->fb_base);
-
-	pci_release_region(pdev, 0);
-	pci_release_region(pdev, 1);
-
-	fb_dealloc_cmap(&info->cmap);
-        framebuffer_release(info);
-
-	pci_disable_device(pdev);
-}
-
 static struct pci_device_id e3d_pci_table[] = {
 	{	PCI_DEVICE(PCI_VENDOR_ID_3DLABS, 0x7a0),	},
 	{	PCI_DEVICE(0x1091, 0x7a0),			},
@@ -434,10 +416,12 @@ static struct pci_device_id e3d_pci_table[] = {
 };
 
 static struct pci_driver e3d_driver = {
+	.driver = {
+		.suppress_bind_attrs = true,
+	},
 	.name		= "e3d",
 	.id_table	= e3d_pci_table,
 	.probe		= e3d_pci_register,
-	.remove		= e3d_pci_unregister,
 };
 
 static int __init e3d_init(void)
@@ -447,16 +431,4 @@ static int __init e3d_init(void)
 
 	return pci_register_driver(&e3d_driver);
 }
-
-static void __exit e3d_exit(void)
-{
-	pci_unregister_driver(&e3d_driver);
-}
-
-module_init(e3d_init);
-module_exit(e3d_exit);
-
-MODULE_DESCRIPTION("framebuffer driver for Sun XVR-500 graphics");
-MODULE_AUTHOR("David S. Miller <davem@davemloft.net>");
-MODULE_VERSION("1.0");
-MODULE_LICENSE("GPL");
+device_initcall(e3d_init);
-- 
2.6.1

[toc] | [prev] | [standalone]

Back to top | Article view | linux.kernel

csiph-web