diff options
| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-05-31 11:22:53 +0200 |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2017-06-01 08:02:14 +0200 |
| commit | 16584b204573ece64de80f20eb6202495aeb35c2 (patch) | |
| tree | 655ffd124df38ea5883e146ece397bb270bcffdc /Documentation | |
| parent | drm: Extract drm_vblank.[hc] (diff) | |
| download | linux-16584b204573ece64de80f20eb6202495aeb35c2.tar.xz linux-16584b204573ece64de80f20eb6202495aeb35c2.zip | |
drm/doc: Polish irq helper documentation
Pull a (much shorter) overview into drm_irq.c, and instead put the
callback documentation into in-line comments in drm_drv.h.
v2: Move the include stanzas back to the split-up patch (Stefan).
Cc: Stefan Agner <stefan@agner.ch>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20170531092253.12833-1-daniel.vetter@ffwll.ch
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/gpu/drm-internals.rst | 54 |
1 files changed, 0 insertions, 54 deletions
diff --git a/Documentation/gpu/drm-internals.rst b/Documentation/gpu/drm-internals.rst index 9067cd9586bd..f6882ad0b3c3 100644 --- a/Documentation/gpu/drm-internals.rst +++ b/Documentation/gpu/drm-internals.rst @@ -149,60 +149,6 @@ Device Instance and Driver Handling Driver Load ----------- -IRQ Registration -~~~~~~~~~~~~~~~~ - -The DRM core tries to facilitate IRQ handler registration and -unregistration by providing :c:func:`drm_irq_install()` and -:c:func:`drm_irq_uninstall()` functions. Those functions only -support a single interrupt per device, devices that use more than one -IRQs need to be handled manually. - -Managed IRQ Registration -'''''''''''''''''''''''' - -:c:func:`drm_irq_install()` starts by calling the irq_preinstall -driver operation. The operation is optional and must make sure that the -interrupt will not get fired by clearing all pending interrupt flags or -disabling the interrupt. - -The passed-in IRQ will then be requested by a call to -:c:func:`request_irq()`. If the DRIVER_IRQ_SHARED driver feature -flag is set, a shared (IRQF_SHARED) IRQ handler will be requested. - -The IRQ handler function must be provided as the mandatory irq_handler -driver operation. It will get passed directly to -:c:func:`request_irq()` and thus has the same prototype as all IRQ -handlers. It will get called with a pointer to the DRM device as the -second argument. - -Finally the function calls the optional irq_postinstall driver -operation. The operation usually enables interrupts (excluding the -vblank interrupt, which is enabled separately), but drivers may choose -to enable/disable interrupts at a different time. - -:c:func:`drm_irq_uninstall()` is similarly used to uninstall an -IRQ handler. It starts by waking up all processes waiting on a vblank -interrupt to make sure they don't hang, and then calls the optional -irq_uninstall driver operation. The operation must disable all hardware -interrupts. Finally the function frees the IRQ by calling -:c:func:`free_irq()`. - -Manual IRQ Registration -''''''''''''''''''''''' - -Drivers that require multiple interrupt handlers can't use the managed -IRQ registration functions. In that case IRQs must be registered and -unregistered manually (usually with the :c:func:`request_irq()` and -:c:func:`free_irq()` functions, or their :c:func:`devm_request_irq()` and -:c:func:`devm_free_irq()` equivalents). - -When manually registering IRQs, drivers must not set the -DRIVER_HAVE_IRQ driver feature flag, and must not provide the -irq_handler driver operation. They must set the :c:type:`struct -drm_device <drm_device>` irq_enabled field to 1 upon -registration of the IRQs, and clear it to 0 after unregistering the -IRQs. IRQ Helper Library ~~~~~~~~~~~~~~~~~~ |