Hi, > -----Original Message----- > From: linux-media-owner@xxxxxxxxxxxxxxx [mailto:linux-media- > owner@xxxxxxxxxxxxxxx] On Behalf Of Lane Brooks > Sent: Thursday, December 02, 2010 11:34 AM > To: Laurent Pinchart > Cc: linux-media@xxxxxxxxxxxxxxx > Subject: Re: Translation Faults on OMAP ISP update > > On 12/02/2010 07:35 AM, Laurent Pinchart wrote: > [snip] > >> Any ideas on the problem? Is there a way to force a reset to the CCDC > so > >> that it will become IDLE? > > Would you expect the ISP to recover gracefully if you removed the > OMAP3530 or > > the RAM from the board and plugged it back ? The same applies to the > sensor > > :-) > > > > Long story short, once started, the CCDC can't be stopped before the end > of > > the image. When you unplug the sensor the CCDC will wait forever for the > end > > of frame. When restarted it will resume working to the previous, no > longer > > mapped buffer, leading to IOMMU faults. > > The CCDC, like most ISP blocks, can't be reset individually. You need to > reset > > the whole ISP to recover from this (blame whoever decided that > individual > > block resets were not useful). This was done before on streamoff, but > now that > > the ISP driver supports running multiple pipelines in parallel we can't > do it > > anymore. > > > > It might be possible to write a clean patch to reset the ISP when all > streams > > are stopped. In the meantime you can rmmod/modprobe the driver. > Laurent, > > Thanks for the feedback. The behavior makes perfect sense now. I can > take it from here. Given the user *can* unplug the sensor module in our > hardware, I need to do something, as locking up the kernel is not > acceptable. I will first look to see if an ISP reset on stream off > works, as we can sacrifice multiple pipeline support (for now). Laurent, Just a question on this: Do we ever plan to support dynamic v4l2_subdevs registration/unregistration? I guess we'll require to "notify" the media controller device, so we add it, (or remove it) from the pipeline, and refresh the links. I think that is going to become an important requirement, as like Lane is doing (unloading a module). It's very likely that we can interchange camera modules, like in the Beagleboard xM, and we don't have a real reason to really not support that. It would be very cool to be able to: 1. Plug Aptina 5MP camera sensor. 2. Load the kernel module 3. Use the camera 4. Unload the kernel module 5. Interchange the camera board for a VGA sensor 6. Load the appropriate sensor driver. All that without needing to restart the board. Does that really sound _that_ crazy to everyone? :) Regards, Sergio > > Lane > -- > To unsubscribe from this list: send the line "unsubscribe linux-media" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
