From mboxrd@z Thu Jan 1 00:00:00 1970 From: maxime.ripard@bootlin.com (Maxime Ripard) Date: Mon, 5 Feb 2018 15:21:55 +0100 Subject: [PATCH 2/2] drm/sun4i: Handle DRM_MODE_FLAG_**SYNC_POSITIVE correctly In-Reply-To: <51323c6d-ba50-f09e-fcd7-d9b18d03673a@micronovasrl.com> References: <59f7b542-3b1d-ff62-e290-37c47f4075ff@micronovasrl.com> <9929d894-53c3-a7e9-a328-a00cfc1ef546@micronovasrl.com> <20180125152117.qikemrwl7f35ssjg@flea.lan> <20180126145608.5s6c6ltpvrko7iyv@flea.lan> <18ec71dc-a785-a771-76d4-176d95032c97@micronovasrl.com> <20180201101411.d23efsjt7jdyi4zh@flea.lan> <51323c6d-ba50-f09e-fcd7-d9b18d03673a@micronovasrl.com> Message-ID: <20180205142155.vgd2olchbwzm6a7x@flea> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Thu, Feb 01, 2018 at 05:09:33PM +0100, Giulio Benetti wrote: > Il 01/02/2018 11:14, Maxime Ripard ha scritto: > > On Sat, Jan 27, 2018 at 11:07:09PM +0100, Giulio Benetti wrote: > > > > > > > I don't really know what the polarity of D0 would be just by > > > > > > > judging at that capture, but we would have noticed if the colors > > > > > > > were inverted for quite some time now. > > > > > > > > > > > > D0-D23 are correct. > > > > > > > > > > > > With that capture, I mean to show you instead dclk is inverted, as > > > > > > dclk samples D0 on falling edge. > > > > > > > > > > Ah right, DCLK being the first channel? > > > > > > > > Yes, sorry I didn't place a label on channels > > > > > > > > > > > > > > > So 0 is NEGEDGE and 1 is POSEDGE(1/3 of clock phase). > > > > > > 1/3 clock phase seems enough to me to be considered POSEDGE, > > > > > > 2/3 instead risks to go too much to the right of D0(even if it > > > > > > could work). > > > > > > > > > > Do you have captures with both settings? > > > > > > > > Not now, but asap I'm going to take. > > > > > > Here we are: > > > 1/3 phase: https://pasteboard.co/H4VehON.png > > > 2/3 phase: https://pasteboard.co/H4Veq8a.png > > > > > > Yellow: D0 > > > Blue: DCLK > > > > > > As you can see: > > > 1/3 phase has DCLK rising edge almost in the middle of D0 > > > 2/3 phase has DCLK rising edge that comes too late > > > > > > I would go for "1/3 phase" for Rising edge and "normal phase" for > > > Falling edge. > > > > > > What do you think? > > > > It seems fair. This need a whole lot of comments though :) > > Yes, then, do I proceed resubmitting both corrected patches with corrected > commit logs? Yes, please. Maxime -- Maxime Ripard, Bootlin (formerly Free Electrons) Embedded Linux and Kernel engineering http://bootlin.com -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 833 bytes Desc: not available URL: