From 6da1d503e7426a88139cb8f6e8b6fb1a412a036a Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Thu, 8 Aug 2013 15:41:23 +0200
Subject: drm: remove FASYNC support

So I've stumbled over drm_fasync and wondered what it does. Digging
that up is quite a story.

First I've had to read up on what this does and ended up being rather
bewildered why peopled loved signals so much back in the days that
they've created SIGIO just for that ...

Then I wondered how this ever works, and what that strange "No-op."
comment right above it should mean. After all calling the core fasync
helper is pretty obviously not a noop. After reading through the
kernels FASYNC implementation I've noticed that signals are only sent
out to the processes attached with FASYNC by calling kill_fasync.

No merged drm driver has ever done that.

After more digging I've found out that the only driver that ever used
this is the so called GAMMA driver. I've frankly never heard of such a
gpu brand ever before. Now FASYNC seems to not have been the only bad
thing with that driver, since Dave Airlie removed it from the drm
driver with prejudice:

commit 1430163b4bbf7b00367ea1066c1c5fe85dbeefed
Author: Dave Airlie <airlied@linux.ie>
Date:   Sun Aug 29 12:04:35 2004 +0000

    Drop GAMMA DRM from a great height ...

Long story short, the drm fasync support seems to be doing absolutely
nothing. And the only user of it was never merged into the upstream
kernel. And we don't need any fops->fasync callback since the fcntl
implementation in the kernel already implements the noop case
correctly.

So stop this particular cargo-cult and rip it all out.

v2: Kill drm_fasync assignments in rcar (newly added) and imx drivers
(somehow I've missed that one in staging). Also drop the reference in
the drm DocBook. ARM compile-fail reported by Rob Clark.

v3: Move the removal of dev->buf_asnyc assignment in drm_setup to this
patch here.

v4: Actually git add ... tsk.

Cc: Dave Airlie <airlied@linux.ie>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Rob Clark <robdclark@gmail.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
(cherry picked from commit b0e898ac555e96e7863a5ee95d70f3625f1db5e2)
Signed-off-by: James Ausmus <james.ausmus@intel.com>

Conflicts:
	drivers/gpu/drm/rcar-du/rcar_du_drv.c
	(driver not in this tree)
Signed-off-by: Darren Hart <dvhart@linux.intel.com>
---
 Documentation/DocBook/drm.tmpl           |    1 -
 drivers/gpu/drm/ast/ast_drv.c            |    1 -
 drivers/gpu/drm/cirrus/cirrus_drv.c      |    1 -
 drivers/gpu/drm/drm_fops.c               |   14 --------------
 drivers/gpu/drm/gma500/psb_drv.c         |    1 -
 drivers/gpu/drm/i810/i810_dma.c          |    1 -
 drivers/gpu/drm/i810/i810_drv.c          |    1 -
 drivers/gpu/drm/i915/i915_drv.c          |    1 -
 drivers/gpu/drm/mga/mga_drv.c            |    1 -
 drivers/gpu/drm/mgag200/mgag200_drv.c    |    1 -
 drivers/gpu/drm/nouveau/nouveau_drm.c    |    1 -
 drivers/gpu/drm/omapdrm/omap_drv.c       |    1 -
 drivers/gpu/drm/qxl/qxl_drv.c            |    1 -
 drivers/gpu/drm/r128/r128_drv.c          |    1 -
 drivers/gpu/drm/radeon/radeon_drv.c      |    2 --
 drivers/gpu/drm/savage/savage_drv.c      |    1 -
 drivers/gpu/drm/shmobile/shmob_drm_drv.c |    1 -
 drivers/gpu/drm/sis/sis_drv.c            |    1 -
 drivers/gpu/drm/tdfx/tdfx_drv.c          |    1 -
 drivers/gpu/drm/tilcdc/tilcdc_drv.c      |    1 -
 drivers/gpu/drm/udl/udl_drv.c            |    1 -
 drivers/gpu/drm/via/via_drv.c            |    1 -
 drivers/gpu/drm/vmwgfx/vmwgfx_drv.c      |    1 -
 drivers/gpu/host1x/drm/drm.c             |    1 -
 drivers/staging/imx-drm/imx-drm-core.c   |    1 -
 include/drm/drmP.h                       |    3 ---
 26 files changed, 42 deletions(-)

--- a/Documentation/DocBook/drm.tmpl
+++ b/Documentation/DocBook/drm.tmpl
@@ -2339,7 +2339,6 @@ void (*postclose) (struct drm_device *,
 	<programlisting>
 	.poll = drm_poll,
 	.read = drm_read,
-	.fasync = drm_fasync,
 	.llseek = no_llseek,
 	</programlisting>
       </para>
--- a/drivers/gpu/drm/ast/ast_drv.c
+++ b/drivers/gpu/drm/ast/ast_drv.c
@@ -190,7 +190,6 @@ static const struct file_operations ast_
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = ast_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = drm_compat_ioctl,
 #endif
--- a/drivers/gpu/drm/cirrus/cirrus_drv.c
+++ b/drivers/gpu/drm/cirrus/cirrus_drv.c
@@ -121,7 +121,6 @@ static const struct file_operations cirr
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = drm_compat_ioctl,
 #endif
-	.fasync = drm_fasync,
 };
 static struct drm_driver driver = {
 	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_USE_MTRR,
--- a/drivers/gpu/drm/drm_fops.c
+++ b/drivers/gpu/drm/drm_fops.c
@@ -79,8 +79,6 @@ static int drm_setup(struct drm_device *
 	dev->last_context = 0;
 	dev->if_version = 0;
 
-	dev->buf_async = NULL;
-
 	DRM_DEBUG("\n");
 
 	/*
@@ -363,18 +361,6 @@ static int drm_open_helper(struct inode
 	return ret;
 }
 
-/** No-op. */
-int drm_fasync(int fd, struct file *filp, int on)
-{
-	struct drm_file *priv = filp->private_data;
-	struct drm_device *dev = priv->minor->dev;
-
-	DRM_DEBUG("fd = %d, device = 0x%lx\n", fd,
-		  (long)old_encode_dev(priv->minor->device));
-	return fasync_helper(fd, filp, on, &dev->buf_async);
-}
-EXPORT_SYMBOL(drm_fasync);
-
 static void drm_master_release(struct drm_device *dev, struct file *filp)
 {
 	struct drm_file *file_priv = filp->private_data;
--- a/drivers/gpu/drm/gma500/psb_drv.c
+++ b/drivers/gpu/drm/gma500/psb_drv.c
@@ -622,7 +622,6 @@ static const struct file_operations psb_
 	.unlocked_ioctl = psb_unlocked_ioctl,
 	.mmap = drm_gem_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 	.read = drm_read,
 };
 
--- a/drivers/gpu/drm/i810/i810_dma.c
+++ b/drivers/gpu/drm/i810/i810_dma.c
@@ -113,7 +113,6 @@ static const struct file_operations i810
 	.release = drm_release,
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = i810_mmap_buffers,
-	.fasync = drm_fasync,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = drm_compat_ioctl,
 #endif
--- a/drivers/gpu/drm/i810/i810_drv.c
+++ b/drivers/gpu/drm/i810/i810_drv.c
@@ -49,7 +49,6 @@ static const struct file_operations i810
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = drm_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = drm_compat_ioctl,
 #endif
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -994,7 +994,6 @@ static const struct file_operations i915
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = drm_gem_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 	.read = drm_read,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = i915_compat_ioctl,
--- a/drivers/gpu/drm/mga/mga_drv.c
+++ b/drivers/gpu/drm/mga/mga_drv.c
@@ -50,7 +50,6 @@ static const struct file_operations mga_
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = drm_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = mga_compat_ioctl,
 #endif
--- a/drivers/gpu/drm/mgag200/mgag200_drv.c
+++ b/drivers/gpu/drm/mgag200/mgag200_drv.c
@@ -81,7 +81,6 @@ static const struct file_operations mgag
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = mgag200_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = drm_compat_ioctl,
 #endif
--- a/drivers/gpu/drm/nouveau/nouveau_drm.c
+++ b/drivers/gpu/drm/nouveau/nouveau_drm.c
@@ -667,7 +667,6 @@ nouveau_driver_fops = {
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = nouveau_ttm_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 	.read = drm_read,
 #if defined(CONFIG_COMPAT)
 	.compat_ioctl = nouveau_compat_ioctl,
--- a/drivers/gpu/drm/omapdrm/omap_drv.c
+++ b/drivers/gpu/drm/omapdrm/omap_drv.c
@@ -583,7 +583,6 @@ static const struct file_operations omap
 		.release = drm_release,
 		.mmap = omap_gem_mmap,
 		.poll = drm_poll,
-		.fasync = drm_fasync,
 		.read = drm_read,
 		.llseek = noop_llseek,
 };
--- a/drivers/gpu/drm/qxl/qxl_drv.c
+++ b/drivers/gpu/drm/qxl/qxl_drv.c
@@ -86,7 +86,6 @@ static const struct file_operations qxl_
 	.release = drm_release,
 	.unlocked_ioctl = drm_ioctl,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 	.mmap = qxl_mmap,
 };
 
--- a/drivers/gpu/drm/r128/r128_drv.c
+++ b/drivers/gpu/drm/r128/r128_drv.c
@@ -48,7 +48,6 @@ static const struct file_operations r128
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = drm_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = r128_compat_ioctl,
 #endif
--- a/drivers/gpu/drm/radeon/radeon_drv.c
+++ b/drivers/gpu/drm/radeon/radeon_drv.c
@@ -259,7 +259,6 @@ static const struct file_operations rade
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = drm_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 	.read = drm_read,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = radeon_compat_ioctl,
@@ -368,7 +367,6 @@ static const struct file_operations rade
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = radeon_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 	.read = drm_read,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = radeon_kms_compat_ioctl,
--- a/drivers/gpu/drm/savage/savage_drv.c
+++ b/drivers/gpu/drm/savage/savage_drv.c
@@ -42,7 +42,6 @@ static const struct file_operations sava
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = drm_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = drm_compat_ioctl,
 #endif
--- a/drivers/gpu/drm/shmobile/shmob_drm_drv.c
+++ b/drivers/gpu/drm/shmobile/shmob_drm_drv.c
@@ -267,7 +267,6 @@ static const struct file_operations shmo
 #endif
 	.poll		= drm_poll,
 	.read		= drm_read,
-	.fasync		= drm_fasync,
 	.llseek		= no_llseek,
 	.mmap		= drm_gem_cma_mmap,
 };
--- a/drivers/gpu/drm/sis/sis_drv.c
+++ b/drivers/gpu/drm/sis/sis_drv.c
@@ -72,7 +72,6 @@ static const struct file_operations sis_
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = drm_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = drm_compat_ioctl,
 #endif
--- a/drivers/gpu/drm/tdfx/tdfx_drv.c
+++ b/drivers/gpu/drm/tdfx/tdfx_drv.c
@@ -48,7 +48,6 @@ static const struct file_operations tdfx
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = drm_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = drm_compat_ioctl,
 #endif
--- a/drivers/gpu/drm/tilcdc/tilcdc_drv.c
+++ b/drivers/gpu/drm/tilcdc/tilcdc_drv.c
@@ -509,7 +509,6 @@ static const struct file_operations fops
 #endif
 	.poll               = drm_poll,
 	.read               = drm_read,
-	.fasync             = drm_fasync,
 	.llseek             = no_llseek,
 	.mmap               = drm_gem_cma_mmap,
 };
--- a/drivers/gpu/drm/udl/udl_drv.c
+++ b/drivers/gpu/drm/udl/udl_drv.c
@@ -65,7 +65,6 @@ static const struct file_operations udl_
 	.read = drm_read,
 	.unlocked_ioctl	= drm_ioctl,
 	.release = drm_release,
-	.fasync = drm_fasync,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = drm_compat_ioctl,
 #endif
--- a/drivers/gpu/drm/via/via_drv.c
+++ b/drivers/gpu/drm/via/via_drv.c
@@ -64,7 +64,6 @@ static const struct file_operations via_
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = drm_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = drm_compat_ioctl,
 #endif
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -1130,7 +1130,6 @@ static const struct file_operations vmwg
 	.mmap = vmw_mmap,
 	.poll = vmw_fops_poll,
 	.read = vmw_fops_read,
-	.fasync = drm_fasync,
 #if defined(CONFIG_COMPAT)
 	.compat_ioctl = drm_compat_ioctl,
 #endif
--- a/drivers/gpu/host1x/drm/drm.c
+++ b/drivers/gpu/host1x/drm/drm.c
@@ -500,7 +500,6 @@ static const struct file_operations tegr
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = tegra_drm_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 	.read = drm_read,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl = drm_compat_ioctl,
--- a/drivers/staging/imx-drm/imx-drm-core.c
+++ b/drivers/staging/imx-drm/imx-drm-core.c
@@ -207,7 +207,6 @@ static const struct file_operations imx_
 	.unlocked_ioctl = drm_ioctl,
 	.mmap = drm_gem_cma_mmap,
 	.poll = drm_poll,
-	.fasync = drm_fasync,
 	.read = drm_read,
 	.llseek = noop_llseek,
 };
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -1169,8 +1169,6 @@ struct drm_device {
 
 	/*@} */
 
-	struct fasync_struct *buf_async;/**< Processes waiting for SIGIO */
-
 	struct drm_agp_head *agp;	/**< AGP data */
 
 	struct device *dev;             /**< Device structure */
@@ -1306,7 +1304,6 @@ extern int drm_lastclose(struct drm_devi
 extern struct mutex drm_global_mutex;
 extern int drm_open(struct inode *inode, struct file *filp);
 extern int drm_stub_open(struct inode *inode, struct file *filp);
-extern int drm_fasync(int fd, struct file *filp, int on);
 extern ssize_t drm_read(struct file *filp, char __user *buffer,
 			size_t count, loff_t *offset);
 extern int drm_release(struct inode *inode, struct file *filp);