From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomi Valkeinen Date: Fri, 24 Aug 2012 08:55:40 +0000 Subject: Re: [PATCH 6/8] OMAPDSS: DSI: calculate dsi clock Message-Id: <1345798540.2614.17.camel@deskari> MIME-Version: 1 Content-Type: multipart/mixed; boundary="=-8MnAUshQ7OPQyyPyKNZ2" List-Id: References: <1345729514-2441-1-git-send-email-tomi.valkeinen@ti.com> <1345729514-2441-7-git-send-email-tomi.valkeinen@ti.com> <50371C47.30708@ti.com> In-Reply-To: <50371C47.30708@ti.com> To: Archit Taneja Cc: linux-omap@vger.kernel.org, linux-fbdev@vger.kernel.org --=-8MnAUshQ7OPQyyPyKNZ2 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2012-08-24 at 11:46 +0530, Archit Taneja wrote: > On Thursday 23 August 2012 07:15 PM, Tomi Valkeinen wrote: > > + /* pck =3D TxByteClkHS * datalanes * 8 / bitsperpixel */ >=20 > This formula looks a bit simplified, we aren't considering the header=20 > and footers of long packets that will add to the DDR clock. But I guess= =20 > not considering these would only give a higher pixel clock than needed,= =20 > which isn't that bad. Hmm. The TRM (omap4460) gives this formula in "10.3.4.5.12 How to Configure the DSI PLL in Video Mode". The headers/footers etc. are handled with adjusting the blanking periods so that DISPC and DSI Tline times match. But obviously they are not used for command mode transfers, so perhaps you have a point there. Then again, at least in theory, in command mode the DISPC pck should be configurable as high as possible because the stall mechanism should stop DISPC when DSI has had enough. And so the pck calculation is a bit unneeded for cmd mode, we could just configure pck to max. But if it's correct for video mode, and very close for cmd mode, I guess it should be fine? Tomi --=-8MnAUshQ7OPQyyPyKNZ2 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) iQIcBAABAgAGBQJQN0GMAAoJEPo9qoy8lh71e2AQAIUw5LQjoe91lYk3VeyjEwfe 9m24LyrLPcHuGi2k3vg2Jbm52Z+jo3LFoisYrB2e4xZkr0Rf1hvT6qRiuArk8o3T WU11VbrspwV205TalFD8e2MrCYQECZApGiBHCHJNV0jylR9V2CeaNmRZIHn2zZSu e9IenIt868qHlfm2aJehao/m6L8xlOUacoaFqkVGEytt+BtrOvEvnwnA3UZkIjaS pd+cpkB+0RWOf88Bn/8VcbP9c7lwgjmnsFAA/k1urPFXngcJmG/ouMVgNNfzaDEe lS8S6j/5DCEsvlOwJRSWYeOCVRvqIkYeB+lsG9jmxtsJ9r2e0gSak26RzNJPmGbP YXu1SBFnxwrPjtyeR4VXElAmoTNTKvWvhZlZ56UEyrRTKLm+1RM7bih565EoiNga H+W7TJYzx7HL1rKkB0n/e5y6+j0nP6Raihk6oRLgod9vNV3kRW8GV+Txwga/gayO NXL6Cyhm4W6U+4mHCIEMFYN7jGCUIuKyLMlmy7Iz0YNgnTvGykqXMz6RZIU1MUer 9cXb7F+2W3FRQlAWv8ewANfo5ogtY8MmQ1IcymS+xLcEShprI9f+nxR50XwtnJuq 7ROB+ut7HswsvVzrVyovR9m68T0Y5G3mRGihE++jsJIBcolU3BUafbHYFI8inldx xnvZNBAULbQAg/hhc9OP =hcmE -----END PGP SIGNATURE----- --=-8MnAUshQ7OPQyyPyKNZ2--