Hi Nico,Thanks for your response, though I enabled Bits 29,28,27 in 0x61110h, the values in 0x61114h returned 0,I have configured the port as eDP in VBIOS not as HDMI/DP, will that make a difference?For eDP which MMIO register need to be checked?ThanksRaoOn Fri, Jul 30, 2021 at 2:47 PM Nico Huber <nico.h@gmx.de> wrote:Hello Rao,
On 30.07.21 13:53, Rao G wrote:
> trying to see the MMIO or VBIOS data when a external display device is
> plugged/unplugged with DP/HDMI interface, which MMIO register is set or
> cleared
I think you are looking at the right register (last one below).
>
> Any inputs are appreciated, some of the registers tried on Port B/Port C
> are given below. when Display is connected and when Display is not
> connected, both these instances
> return the same data. Looking for register/bit that sets/clears when
> external display is connected/disconnected
>
> printk(BIOS_DEBUG, "Intel Gfx BAR GTTMMADR\n");
> printk(BIOS_DEBUG, " DP_B %X\n", read32(bar+0x180000+0x64100));
> printk(BIOS_DEBUG, " DP_C %X\n", read32(bar+0x180000+0x64200));
> printk(BIOS_DEBUG, " HDMIC %X\n", read32(bar+0x180000+0x61160));
> printk(BIOS_DEBUG, " HDMIB %X\n", read32(bar+0x180000+0x61140));
> printk(BIOS_DEBUG, " Hotplug control %X\n", read32(bar+0x180000+0x61164));
> printk(BIOS_DEBUG, " pipeA control %X\n", read32(bar+0x180000+0x61204));
> printk(BIOS_DEBUG, " pipeB control %X\n", read32(bar+0x180000+0x61304));
> printk(BIOS_DEBUG, " porthot plug stat %X\n", read32(bar+0x180000+0x61114));
According to the datasheet, the bits in this register should change but
only if enabled in PORT_HOTPLUG_EN (0x61110).
Nico
NB. There is also libgfxinit support under review [1]. In case you are
trying to do some native graphics init ;)
[1] https://review.coreboot.org/q/topic:%2522baytrail-libgfxinit%2522