When I was writing an atomic wrapper for rmfb, I ran into the
following backtrace from lockdep:
=============================================
[ INFO: possible recursive locking detected ]
4.5.0-patser+ #4696 Tainted: G U
---------------------------------------------
kworker/2:2/2608 is trying to acquire lock:
(crtc_ww_class_mutex){+.+.+.}, at: [<ffffffffc00c9ddc>] drm_modeset_lock+0x7c/0x120 [drm]
but task is already holding lock:
(crtc_ww_class_mutex){+.+.+.}, at: [<ffffffffc00c98cd>] modeset_backoff+0x8d/0x220 [drm]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(crtc_ww_class_mutex);
lock(crtc_ww_class_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
4 locks held by kworker/2:2/2608:
#0: ("events"){.+.+.+}, at: [<ffffffff810a5eea>] process_one_work+0x15a/0x6c0
#1: ((&arg.work)){+.+.+.}, at: [<ffffffff810a5eea>] process_one_work+0x15a/0x6c0
#2: (crtc_ww_class_acquire){+.+.+.}, at: [<ffffffffc004532a>] drm_atomic_helper_remove_fb+0x4a/0x1d0 [drm_kms_helper]
#3: (crtc_ww_class_mutex){+.+.+.}, at: [<ffffffffc00c98cd>] modeset_backoff+0x8d/0x220 [drm]
While lockdep probably catches this bug when it happens, it's better
to explicitly warn when state->acquire_ctx is not set.
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1462266751-29123-1-git-send-email-maarten.lankhorst@linux.intel.com
The fsl dcu now uses the clk-provider interfaces, which are not available
when CONFIG_COMMON_CLK is disabled:
drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c: In function 'fsl_dcu_drm_probe':
drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_drv.c:362:20: error: implicit declaration of function '__clk_get_name' [-Werror=implicit-function-declaration]
pix_clk_in_name = __clk_get_name(pix_clk_in);
This adds a Kconfig dependency to prevent the driver from being enabled
in this case.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 2d701449bc ("drm/fsl-dcu: use common clock framework for pixel clock divider")
Acked-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1462186839-2224021-1-git-send-email-arnd@arndb.de
This is the first step of renaming async commit to nonblocking commit.
The flag passed by userspace is NONBLOCKING, and async has a different
meaning for page flips, where it means as soon as possible.
Fixing up comments in drm core is done manually, to make sure I didn't
miss anything.
For drivers, the following cocci script is used to rename bool async to bool
nonblock:
@@
identifier I =~ "^async";
identifier func;
@@
func(..., bool
- I
+ nonblock
, ...)
{
<...
- I
+ nonblock
...>
}
@@
identifier func;
type T;
identifier I =~ "^async";
@@
T func(..., bool
- I
+ nonblock
, ...);
Thanks to Tvrtko Ursulin for the cocci script.
Cc: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com>
Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461679905-30177-2-git-send-email-maarten.lankhorst@linux.intel.com
This adds fbdev deferred io support if CONFIG_FB_DEFERRED_IO is enabled.
The driver has to provide a (struct drm_framebuffer_funcs *)->dirty()
callback to get notification of fbdev framebuffer changes.
If the dirty() hook is set, then fb_deferred_io is set up automatically
by the helper.
Two functions have been added so that the driver can provide a dirty()
function:
- drm_fbdev_cma_init_with_funcs()
This makes it possible for the driver to provided a custom
(struct drm_fb_helper_funcs *)->fb_probe() function.
- drm_fbdev_cma_create_with_funcs()
This is used by the .fb_probe hook to set a driver provided
(struct drm_framebuffer_funcs *)->dirty() function.
Cc: laurent.pinchart@ideasonboard.com
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461856717-6476-6-git-send-email-noralf@tronnes.org
Export fb_deferred_io_mmap so drivers can change vma->vm_page_prot.
When the framebuffer memory is allocated using dma_alloc_writecombine()
instead of vmalloc(), I get cache syncing problems on ARM.
This solves it:
static int drm_fbdev_cma_deferred_io_mmap(struct fb_info *info,
struct vm_area_struct *vma)
{
fb_deferred_io_mmap(info, vma);
vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
return 0;
}
Could this have been done in the core?
Drivers that don't set (struct fb_ops *)->fb_mmap, gets a call to
fb_pgprotect() at the end of the default fb_mmap implementation
(drivers/video/fbdev/core/fbmem.c). This is an architecture specific
function that on many platforms uses pgprot_writecombine(), but not on
all. And looking at some of the fb_mmap implementations, some of them
sets vm_page_prot to nocache for instance, so I think the safest bet is
to do this in the driver and not in the fbdev core. And we can't call
fb_pgprotect() from fb_deferred_io_mmap() either because we don't have
access to the file pointer that powerpc needs.
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Acked-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461856717-6476-5-git-send-email-noralf@tronnes.org
