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Diffstat (limited to 'glew/auto/EGL-Registry/extensions/EXT/EGL_EXT_device_drm.txt')
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diff --git a/glew/auto/EGL-Registry/extensions/EXT/EGL_EXT_device_drm.txt b/glew/auto/EGL-Registry/extensions/EXT/EGL_EXT_device_drm.txt new file mode 100644 index 0000000..fa125fc --- /dev/null +++ b/glew/auto/EGL-Registry/extensions/EXT/EGL_EXT_device_drm.txt @@ -0,0 +1,223 @@ +Name + + EXT_device_drm + EXT_output_drm + +Name Strings + + EGL_EXT_device_drm + EGL_EXT_output_drm + +Contributors + + Daniel Kartch + James Jones + Christopher James Halse Rogers + +Contacts + + Daniel Kartch, NVIDIA (dkartch 'at' nvidia.com) + +Status + + Complete + +Version + + Version 5 - December 28th, 2015 + +Number + + EGL Extension #79 + +Extension Type + + EGL device extension for EGL_EXT_device_drm + + EGL display extension for EGL_EXT_output_drm + +Dependencies + + EGL_EXT_device_drm requires EGL_EXT_device_base. + + EGL_EXT_device_drm interacts with EGL_EXT_platform_device + + EGL_EXT_device_drm requires a DRM driver. + + EGL_EXT_output_drm requires EGL_EXT_output_base. + + EGL_EXT_output_drm requires a DRM driver which supports KMS. + + An EGLDisplay supporting EGL_EXT_output_drm must be associated + with an EGLDevice supporting EGL_EXT_device_drm. + +Overview + + Increasingly, EGL and its client APIs are being used in place of + "native" rendering APIs to implement the basic graphics + functionality of native windowing systems. This creates demand + for a method to initialize EGL displays and surfaces directly on + top of native GPU or device objects rather than native window + system objects. The mechanics of enumerating the underlying + native devices and constructing EGL displays and surfaces from + them have been solved in various platform and implementation- + specific ways. The EGL device family of extensions offers a + standardized framework for bootstrapping EGL without the use of + any underlying "native" APIs or functionality. + + These extensions define how to map device and output handles between + EGL and DRM/KMS. An EGL implementation which provides these + extensions must have access to sufficient knowledge of the DRM + implementation to be able to perform these mappings. No requirements + are imposed on how this information is obtained, nor does this + support have any implications for how EGL devices and outputs are + implemented. Among the possibilities, support may be implemented in + a generic fashion by layering on top of DRM, or EGL and DRM backends + may be provided by the same vendor and share privileged lower level + resources. An implementation which supports these extensions may + support other low level device interfaces, such as OpenWF Display, + as well. + +New Types + + None + +New Procedures and Functions + + None + +New Tokens + + Added by EXT_device_drm: + + Accepted as the <name> parameter of eglQueryDeviceStringEXT + + EGL_DRM_DEVICE_FILE_EXT 0x3233 + + If EGL_EXT_platform_device is present, the following is accepted + in the <attrib_list> of eglGetPlatformDisplayEXT(). + + EGL_DRM_MASTER_FD_EXT 0x333C + + Added by EXT_output_drm: + + Accepted in the <attrib_list> of eglGetOutputLayersEXT and as + the <attribute> parameter of eglQueryOutputLayerAttribEXT + + EGL_DRM_CRTC_EXT 0x3234 + EGL_DRM_PLANE_EXT 0x3235 + + Accepted in the <attrib_list> of eglGetOutputPortsEXT and as + the <attribute> parameter of eglQueryOutputPortAttribEXT + + EGL_DRM_CONNECTOR_EXT 0x3236 + +New Behavior for EXT_device_drm + + EGLDeviceEXTs may be mapped to DRM device files. + + To obtain a DRM device file for an EGLDeviceEXT, call + eglQueryDeviceStringEXT with <name> set to EGL_DRM_DEVICE_FILE_EXT. + The function will return a pointer to a string containing the name + of the device file (e.g. "/dev/dri/cardN"). + +If EGL_EXT_platform_device is present, replace the last sentence of the +third paragraph in section 3.2 "Initialization" with the following: + + When <platform> is EGL_PLATFORM_DEVICE_EXT, the only valid attribute + name is EGL_DRM_MASTER_FD_EXT. If specified, the value must be a file + descriptor with DRM master permissions on the DRM device associated + with the specified EGLDevice, as determined by EGL_DRM_DEVICE_FILE_EXT. + If the file descriptor does not refer to the correct DRM device or + does not have master permissions, the behavior is undefined. Calls to + eglGetPlatformDeviceEXT() with the same values for <platform> and + <native_display> but distinct EGL_DRM_MASTER_FD_EXT values will return + separate EGLDisplays. + + If EGL requires the use of the DRM file descriptor beyond the duration + of the call to eglGetPlatformDispay(), it will duplicate it. If no + file descriptor is specified and EGL requires one, it will attempt to + open the device itself. Applications should only need to specify a + file descriptor in situations where EGL may fail to open a file + descriptor itself, generally due to lack of permissions, or when EGL + will fail to acquire DRM master permissions due to conflicts with an + existing DRM client. DRM master permissions are only required when EGL + must modify output attributes. This extension does not define any + situations in which output attributes will be modified. + +New Behavior for EXT_output_drm + + KMS CRTC, plane, and connector IDs may be used to restrict EGL + output handle searches and may be queried from EGL output handles. + + Add to Table 3.10.3.1 in EGL_EXT_output_base: + + Attribute Type Access + --------------------- ------- ------ + EGL_DRM_CRTC_EXT integer S|R + EGL_DRM_PLANE_EXT integer S|R + + Add to Table 3.10.3.2 in EGL_EXT_output_base: + + Attribute Type Access + --------------------- ------- ------ + EGL_DRM_CONNECTOR_EXT integer S|R + + Add to description of eglOutputLayerAttribEXT: + + If <layer> corresponds to a KMS CRTC and <attribute> is + EGL_DRM_PLANE_EXT, or if <layer> corresponds to a KMS plane and + <attribute> is EGL_DRM_CRTC_EXT, an EGL_BAD_MATCH error is + generated. + +Issues + + 1) Should different values of EGL_DRM_MASTER_FD_EXT result in separate + EGLDisplays? + + RESOLVED: Yes. Consider an application made up of two independent + modules running in two independently scheduled threads. Each + module calls eglGetPlatformDisplayEXT(): + + int fd = open("/dev/dri/card0", O_RDWR); + int attr1[] = { EGL_DRM_MASTER_FD_EXT, fd }; + dpy1 = eglGetPlatformDisplayEXT(EGL_PLATFORM_DEVICE_EXT, + eglDev, + attr1); + + ... + + dpy2 = eglGetPlatformDisplayEXT(EGL_PLATFORM_DEVICE_EXT, + eglDev, + NULL); + + Presumably, if dpy1 == dpy2, they would both be using the same DRM + fd for output operations internally. That would mean display + attribute updates would likely fail if dpy2 happened to be created + before dpy1. This would be painful to debug. If dpy2 != dpy1, + failure for dpy2 would be consistent and obvious. The application + author would be required to work out a scheme to share the master + FD between modules before creating EGL displays. + +Revision History: + + #5 (December 28th, 2015) James Jones + - Added EGL_DRM_MASTER_FD_EXT and associated + language. + - Added issue 1. + + #4 (August 22nd, 2014) James Jones + - Marked complete. + - Listed Daniel as the contact. + + #3 (June 5th, 2014) Daniel Kartch + - Assigned enumerated values for constants. + + #2 (May 28th, 2014) Daniel Kartch + - Simplified description of new behavior based on refinements + to EGL_EXT_output_base. + + #1 (January 31st, 2014) Daniel Kartch + - Initial draft, representing a signficant reworking of + functionality previously proposed in + EGL_EXT_native_device_drm. |