Messages in this thread | | | Date | Tue, 6 Oct 2015 15:01:36 -0300 | Subject | Re: [PATCH 11/12] drm: bridge/dw_hdmi: add connector mode forcing | From | Fabio Estevam <> |
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On Sat, Aug 8, 2015 at 1:04 PM, Russell King <rmk+kernel@arm.linux.org.uk> wrote: > When connected to HDMI sources, some DVI monitors de-assert their HPD > signal and TDMS loads for one seconds every four seconds when there is > no signal present on the connection. > > Unfortunately, this behaviour is indistinguishable from a proper HDMI > setup with an AV receiver in the path to the display: the HDMI spec > requires us to detect HPD deassertions as short as 100ms, which indicate > that the EDID has changed. > > Since it is possible to connect a DVI monitor to an AV receiver and then > to a HDMI source, merely working around this by detecting the lack of > HDMI vendor block in the EDID is insufficient - the AV receiver is at > liberty to modify the EDID as it sees fit, and it will place its own > parameters into the EDID including the HDMI vendor block. > > DRM has support for forcing the state of a connector, which we should > implement to allow us to work around these broken DVI monitors - we can > tell DRM to force the connection state to indicate that there is always > a device connected to work around this problem. Although this requires > manual configuration, it is better than nothing at all. > > When a forced connection state has been set, there is no point handling > our RXSENSE interrupts, so disable them in this circumstance. > > Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Reviewed-by: Fabio Estevam@freescale.com
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