[PATCH] Kconfig: disable Media Controller for DVB
Since when we start discussions about the usage Media Controller for complex hardware, one thing become clear: the way it is, MC fails to map anything different than capture/output/m2m video-only streaming. The point is that MC has entities named as devnodes, but the only devnode used (before the DVB patches) is MEDIA_ENT_T_DEVNODE_V4L. Due to the way MC got implemented, however, this entity actually doesn't represent the devnode, but the hardware I/O engine that receives data via DMA. By coincidence, such DMA is associated with the V4L device node on webcam hardware, but this is not true even for other V4L2 devices. For example, on USB hardware, the DMA is done via the USB controller. The data passes though a in-kernel filter that strips off the URB headers. Other V4L2 devices like radio may not even have DMA. When it have, the DMA is done via ALSA, and not via the V4L devnode. In other words, MC is broken as a whole, but tagging it as BROKEN right now would do more harm than good. So, instead, let's mark, for now, the DVB part as broken and block all new changes to MC while we fix this mess, whith we hopefully will do for the next Kernel version. Requested-by: Laurent Pinchart laurent.pinch...@ideasonboard.com Signed-off-by: Hans Verkuil hans.verk...@cisco.com Acked-by: Laurent Pinchart laurent.pinch...@ideasonboard.com Signed-off-by: Mauro Carvalho Chehab mche...@osg.samsung.com diff --git a/drivers/media/Kconfig b/drivers/media/Kconfig index 3ef0f90b128f..157099243d61 100644 --- a/drivers/media/Kconfig +++ b/drivers/media/Kconfig @@ -97,6 +97,7 @@ config MEDIA_CONTROLLER config MEDIA_CONTROLLER_DVB bool Enable Media controller for DVB depends on MEDIA_CONTROLLER + depends on BROKEN ---help--- Enable the media controller API support for DVB. -- 2.4.3 -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH] Kconfig: disable Media Controller for DVB
Since when we start discussions about the usage Media Controller for complex hardware, one thing become clear: the way it is, MC fails to map anything different than capture/output/m2m video-only streaming. The point is that MC has entities named as devnodes, but the only devnode used (before the DVB patches) is MEDIA_ENT_T_DEVNODE_V4L. Due to the way MC got implemented, however, this entity actually doesn't represent the devnode, but the hardware I/O engine that receives data via DMA. By coincidence, such DMA is associated with the V4L device node on webcam hardware, but this is not true even for other V4L2 devices. For example, on USB hardware, the DMA is done via the USB controller. The data passes though a in-kernel filter that strips off the URB headers. Other V4L2 devices like radio may not even have DMA. When it have, the DMA is done via ALSA, and not via the V4L devnode. In other words, MC is broken as a whole, but tagging it as BROKEN right now would do more harm than good. So, instead, let's mark, for now, the DVB part as broken and block all new changes to MC while we fix this mess, whith we hopefully will do for the next Kernel version. Requested-by: Laurent Pinchart laurent.pinch...@ideasonboard.com Acked-by: Laurent Pinchart laurent.pinch...@ideasonboard.com Signed-off-by: Hans Verkuil hans.verk...@cisco.com Signed-off-by: Mauro Carvalho Chehab mche...@osg.samsung.com --- drivers/media/Kconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/media/Kconfig b/drivers/media/Kconfig index 3ef0f90b128f..157099243d61 100644 --- a/drivers/media/Kconfig +++ b/drivers/media/Kconfig @@ -97,6 +97,7 @@ config MEDIA_CONTROLLER config MEDIA_CONTROLLER_DVB bool Enable Media controller for DVB depends on MEDIA_CONTROLLER + depends on BROKEN ---help--- Enable the media controller API support for DVB. -- 2.4.3 -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH] Kconfig: disable Media Controller for DVB
Since when we start discussions about the usage Media Controller for complex hardware, one thing become clear: the way it is, MC fails to map anything more complex than a webcam. The point is that MC has entities named as devnodes, but the only devnode used (before the DVB patches) is MEDIA_ENT_T_DEVNODE_V4L. Due to the way MC got implemented, however, this entity actually doesn't represent the devnode, but the hardware I/O engine that receives data via DMA. By coincidence, such DMA is associated with the V4L device node on webcam hardware, but this is not true even for other V4L2 devices. For example, on USB hardware, the DMA is done via the USB controller. The data passes though a in-kernel filter that strips off the URB headers. Other V4L2 devices like radio may not even have DMA. When it have, the DMA is done via ALSA, and not via the V4L devnode. In other words, MC is broken as a hole, but tagging it as BROKEN right now would do more harm than good. So, instead, let's mark, for now, the DVB part as broken and block all new changes to it while we don't fix this mess, with we hopefully will do for the next Kernel version. Requested-by: Laurent Pinchart laurent.pinch...@ideasonboard.com Signed-off-by: Mauro Carvalho Chehab mche...@osg.samsung.com diff --git a/drivers/media/Kconfig b/drivers/media/Kconfig index 3ef0f90b128f..157099243d61 100644 --- a/drivers/media/Kconfig +++ b/drivers/media/Kconfig @@ -97,6 +97,7 @@ config MEDIA_CONTROLLER config MEDIA_CONTROLLER_DVB bool Enable Media controller for DVB depends on MEDIA_CONTROLLER + depends on BROKEN ---help--- Enable the media controller API support for DVB. -- 2.4.2 -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] Kconfig: disable Media Controller for DVB
On 06/12/2015 12:57 PM, Mauro Carvalho Chehab wrote: Since when we start discussions about the usage Media Controller for complex hardware, one thing become clear: the way it is, MC fails to map anything more complex than a webcam. The point is that MC has entities named as devnodes, but the only devnode used (before the DVB patches) is MEDIA_ENT_T_DEVNODE_V4L. Due to the way MC got implemented, however, this entity actually doesn't represent the devnode, but the hardware I/O engine that receives data via DMA. By coincidence, such DMA is associated with the V4L device node on webcam hardware, but this is not true even for other V4L2 devices. For example, on USB hardware, the DMA is done via the USB controller. The data passes though a in-kernel filter that strips off the URB headers. Other V4L2 devices like radio may not even have DMA. When it have, the DMA is done via ALSA, and not via the V4L devnode. In other words, MC is broken as a hole, but tagging it as BROKEN hole - whole One of these days you'll have retrained your brain for this :-) right now would do more harm than good. So, instead, let's mark, for now, the DVB part as broken and block all new changes to it while we don't fix this mess, with while we fix this mess, which After fixing the typos: Signed-off-by: Hans Verkuil hans.verk...@cisco.com Regards, Hans we hopefully will do for the next Kernel version. Requested-by: Laurent Pinchart laurent.pinch...@ideasonboard.com Signed-off-by: Mauro Carvalho Chehab mche...@osg.samsung.com diff --git a/drivers/media/Kconfig b/drivers/media/Kconfig index 3ef0f90b128f..157099243d61 100644 --- a/drivers/media/Kconfig +++ b/drivers/media/Kconfig @@ -97,6 +97,7 @@ config MEDIA_CONTROLLER config MEDIA_CONTROLLER_DVB bool Enable Media controller for DVB depends on MEDIA_CONTROLLER + depends on BROKEN ---help--- Enable the media controller API support for DVB. -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] Kconfig: disable Media Controller for DVB
Em Fri, 12 Jun 2015 13:02:00 +0200 Hans Verkuil hverk...@xs4all.nl escreveu: On 06/12/2015 12:57 PM, Mauro Carvalho Chehab wrote: Since when we start discussions about the usage Media Controller for complex hardware, one thing become clear: the way it is, MC fails to map anything more complex than a webcam. The point is that MC has entities named as devnodes, but the only devnode used (before the DVB patches) is MEDIA_ENT_T_DEVNODE_V4L. Due to the way MC got implemented, however, this entity actually doesn't represent the devnode, but the hardware I/O engine that receives data via DMA. By coincidence, such DMA is associated with the V4L device node on webcam hardware, but this is not true even for other V4L2 devices. For example, on USB hardware, the DMA is done via the USB controller. The data passes though a in-kernel filter that strips off the URB headers. Other V4L2 devices like radio may not even have DMA. When it have, the DMA is done via ALSA, and not via the V4L devnode. In other words, MC is broken as a hole, but tagging it as BROKEN hole - whole One of these days you'll have retrained your brain for this :-) Heh ;) right now would do more harm than good. So, instead, let's mark, for now, the DVB part as broken and block all new changes to it while we don't fix this mess, with while we fix this mess, which Changed to: block all new changes to MC while we fix this mess, which Sending version 2. Regards, Mauro -- To unsubscribe from this list: send the line unsubscribe linux-media in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
