Mauro, Any suggestions on addressing this issue ? Murali Karicheri Software Design Engineer Texas Instruments Inc. Germantown, MD 20874 new phone: 301-407-9583 Old Phone : 301-515-3736 (will be deprecated) email: m-karicheri2@xxxxxx >-----Original Message----- >From: linux-media-owner@xxxxxxxxxxxxxxx [mailto:linux-media- >owner@xxxxxxxxxxxxxxx] On Behalf Of Hans Verkuil >Sent: Thursday, July 30, 2009 10:57 AM >To: Karicheri, Muralidharan >Cc: Laurent Pinchart; Mauro Carvalho Chehab; Dongsoo, Nathaniel Kim; >v4l2_linux; Dongsoo Kim; 박경민; jm105.lee@xxxxxxxxxxx; >�세문; 대�기; 김ؕ준 >Subject: RE: How to save number of times using memcpy? > > >> Mauro, >> >> What do you suggest for this? Could we allocate coherent device memory >> using dma_declare_coherent_memory() ? This seems the only way to do it >> unless, video buffer layer does this when initializing the queue. > >Or to be able to override the memory allocation in some way. Large >contiguous buffers are hard to get once a system has been running for a >while, so at least some buffers must be allocated up front and not on the >first open() or VIDIOC_REQBUFS call. I'm surprised that this issue hasn't >cropped up before. > >Regards, > > Hans > >> >> Murali Karicheri >> Software Design Engineer >> Texas Instruments Inc. >> Germantown, MD 20874 >> Phone : 301-515-3736 >> email: m-karicheri2@xxxxxx >> >>>-----Original Message----- >>>From: linux-media-owner@xxxxxxxxxxxxxxx [mailto:linux-media- >>>owner@xxxxxxxxxxxxxxx] On Behalf Of Hans Verkuil >>>Sent: Thursday, July 30, 2009 10:26 AM >>>To: Karicheri, Muralidharan >>>Cc: Laurent Pinchart; Mauro Carvalho Chehab; Dongsoo, Nathaniel Kim; >>>v4l2_linux; Dongsoo Kim; 박경민; jm105.lee@xxxxxxxxxxx; >>>�세문; 대�기; 김ؕ준 >>>Subject: RE: How to save number of times using memcpy? >>> >>> >>>> Hans, >>>> >>>> I don't see the code you are referring to. Here is the probe() from the >>>> next branch of v4l-dvb. Could you point out the code that does the >>>> allocation of frame buffers ? I had used this code as reference when >>>> developing vpfe capture driver. >>>> >>>> Murali >>> >>>My apologies, I got it mixed up with older versions of this driver. I see >>>that it now uses videobuf-dma-contig. This is going to be a real problem >>>since this makes it impossible (or at least very hard) to allocate memory >>>up front. I'm no expert on videobuf, but this is something that should be >>>addressed, especially in the dma-contig case. >>> >>>Regards, >>> >>> Hans >>> >>>-- >>>Hans Verkuil - video4linux developer - sponsored by TANDBERG >>> >>>-- >>>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 >> >> >> > > >-- >Hans Verkuil - video4linux developer - sponsored by TANDBERG > >-- >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
