Created attachment 96878 [details]
3200X1800 eDP panel

System Environment:
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Platform: BDW
kernel:   (drm-intel-nightly)b2f42c87ceb21108f04b17b651ad1f7c6e808f79

Bug detailed description:
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3200X1800 eDP panel unable to display, but the eDP panel is able to detect. Here is information of testdisplay:
[root@x-bdw01 tests]# ./testdisplay -i
Connectors:
id      encoder status          type    size (mm)       modes
14      13      connected       eDP     290x170         2
  modes:
  name refresh (Hz) hdisp hss hse htot vdisp vss vse vtot flags type clock
[0]  3200x1800 60 3200 3248 3280 3316 1800 1802 1807 1816 0xa 0x48 361310
[1]  3200x1800 52 3200 3248 3280 3424 1800 1802 1807 2045 0xa 0x40 361310
23      0       disconnected    DP      700x390         0
24      0       disconnected    HDMI-A  0x0             0
26      0       disconnected    HDMI-A  0x0             0

CRTCs:
id      fb      pos     size
5       52      (0,0)   (3200x1800)
  3200x1800 60 3200 3248 3280 3316 1800 1802 1807 1816 0xa 0x48 361310
8       0       (0,0)   (0x0)
   0 0 0 0 0 0 0 0 0 0x0 0x0 0
11      0       (0,0)   (0x0)
   0 0 0 0 0 0 0 0 0 0x0 0x0 0


I got 3200X1800 eDP panel just now, and this is first time to run test on 3200X1800 eDP panel.


Reproduce steps:
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1.  Boot the OS with 3200X1800 eDP