On Wed, Jul 26, 2017 at 11:05:39AM +0100, Russell King wrote: > Some ARM platforms do not wire the HDLCD interrupt. Allow hdlcd to > initialise without an interrupt present. > > Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx> This isn't fully functional on ARM MPS platforms yet, but at least gets us further. Without any display connected: [ 14.315986] [drm] found ARM HDLCD version r0p0 [ 14.557038] tda998x 2-0070: found TDA19988 [ 14.622232] hdlcd 40205000.hdlcd: bound 2-0070 (ops 0x213534) [ 14.630406] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013). [ 14.639335] [drm] No driver support for vblank timestamp query. [ 14.653210] [drm] Cannot find any crtc or sizes - going 1024x768 [ 15.232556] hdlcd 40205000.hdlcd: fb0: frame buffer device [ 15.284076] [drm] Initialized hdlcd 1.0.0 20151021 for 40205000.hdlcd on minor 0 With a TV connected, the driver doesn't initialise: [ 14.422810] [drm] found ARM HDLCD version r0p0 [ 14.657227] tda998x 2-0070: found TDA19988 [ 14.722439] hdlcd 40205000.hdlcd: bound 2-0070 (ops 0x213534) [ 14.730613] [drm] Supports vblank timestamp caching Rev 2 (21.10.2013). [ 14.739538] [drm] No driver support for vblank timestamp query. [ 15.311977] hdlcd 40205000.hdlcd: Failed to set initial hw configuration. [ 15.357402] hdlcd 40205000.hdlcd: master bind failed: -12 [ 15.365082] tda998x: probe of 2-0070 failed with error -12 I don't think this is correct behaviour - if we fail to set an initial configuration (which will be based on the resolution of the connected display) why should the driver fail to probe - it's not that there is no device, it's (in this case) that there aren't the resources for the chosen mode. Userspace could always try setting a different mode. I suspect the above failure is down to either (a) not having enough memory available to allocate a 1920x1080 frame buffer, or (b) not (yet) being able to program the hdlcd pixel clock for this platform, which is currently hard-coded in DT at 23.75MHz. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line: currently at 9.6Mbps down 400kbps up according to speedtest.net. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
