From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Date: Fri, 14 Sep 2012 08:27:43 +0000 Subject: Re: [PATCH 00/21] OMAPDSS: DISPC changes for writeback pipeline Message-Id: <1347611263.2559.44.camel@deskari> MIME-Version: 1 Content-Type: multipart/mixed; boundary="=-GXE1kr1MhAey7Y/cKhBo" List-Id: References: <1347538505-25359-1-git-send-email-archit@ti.com> In-Reply-To: <1347538505-25359-1-git-send-email-archit@ti.com> To: Archit Taneja Cc: linux-omap@vger.kernel.org, linux-fbdev@vger.kernel.org --=-GXE1kr1MhAey7Y/cKhBo Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2012-09-13 at 17:44 +0530, Archit Taneja wrote: > DSS HW on OMAP4 onwards supports a new pipeline called writeback. Unlike = other > pipelines(called overlays in OMAPDSS), writeback takes pixel data from an > overlay output or a overlay manager output and writes it back into a spec= ified > address in memory. >=20 > writeback pipeline allows us to take benefit of the hardware processing > available inside the DISPC like color space conversion, rescaling, compos= iting > etc and do either a) perform memory-to-memory transfer with data processi= ng, > b) capture a displayed frame. The former is known as memory to memory mod= e of > the writeback pipeline, and the latter is known as capture mode. More det= ails > about writeback can be found in the Display Subsystem section of the OMAP= 4/5 TRMs. >=20 > witeback has properties of both overlays and overlay managers. It is like= an > overlay as it has programmable base addresses and contains blocks like sc= alar, You consistently use the term "scalar" in the patches, but I believe the correct term is "scaler". > color conversion unit, truncation unit, DISPC DMA FIFO. It is like a mana= ger as > enabling it immediately starts transfer to the memory, and it has a GO bi= t to use > a new writeback configuration. >=20 > This series prepares the low level DISPC driver(dispc.c) to configure wri= teback > registers. The aim is to reuse most of the code as most of its registers = are > like overlay or manager registers, and are configured in the same way in = most > cases. The first few patches rename dispc_ovl_* functions to dispc_plane_= * I'm not sure if the renaming causes more confusion than clarity... It kinda creates a mishmash of ovl/plane names, and the term "plane" doesn't really sound like it's a base for both overlays and wb. Could we consider the wb as a special case, and keep the ovl name for most of the things and have "wb" used for wb specific things? > functions. The next few patches change how overlay caps are used within t= he > dispc functions, this helps reusing more functions between overlays and I dislike this a bit, I think dispc driver should know what HW it has, you shouldn't need to pass caps to it. So I'd prefer the dispc driver to to have this information in dispc_features. I believe all OVL_CAPS should be there, and then exported to other drivers via some means. I guess this means could for now be just initializing ovl->caps with data from dispc.c. Tomi --=-GXE1kr1MhAey7Y/cKhBo Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQIcBAABAgAGBQJQUup/AAoJEPo9qoy8lh71Pi8P/39FOBwXSRyPEgaOujbcZ1nl ZRf2eqe2VvmDCR+iAe5WVS1AEb8fzK1Y5ej4MHiYKQb7bnD6y3KhFBOIHueqet1n X01V1rMIa1UFN1SKS+BzCUzOtYw1yemOhh65/0ueZsjizeLKDdgkYrWkc4eiSG/Y MuiJjRy9qKW9HBQUH8oTfh2EznSOX9rGwMiXHKI4wUNuof580EvsxVgWukbZgat8 Q3gRnD2Xd78GRTny/o5UdyrNjHfOvptMhDyuqNRaIFLaz0Gvs6mGVYLyMkQLzP/L HJ7OE14t1HCDsMSFwUa8PBuRY1SOTp012P9jwchxBA9WI0KMcVehS4w60oSK2U8c k3HSs4IMHt7GG7f2+gi1WAkdJ5wsdnKJrLkdGH8MZQzZtDedBk5+kPNZvv3QRBGU uhDNqfNn/cr/T+n479obCjMi2HyKRpW37sITAmzaK2YLwXdpXTdWJvPR6kmA92h8 /zkrEy+pUmdKJL06If25HAG+Y/36YZROp0zSRjW6Xhhc7R6c/HZxldh5om6SWQY5 NjERMIDVCMorKHpF2baCkrUcS5q9tYw/zNzHyWgCt757ZQH3jDf9OpJs81MTKDMm LgG8vV/HxbLwqkYKdGQ/S/5DaWczj/+bRctHug04SG0T23xgEpp+p70SgGMp31Ua H9xKgC/+g3QzbXe+qN/o =akSR -----END PGP SIGNATURE----- --=-GXE1kr1MhAey7Y/cKhBo--