Date: Mon, 25 Feb 2013 03:30:41 +0100 From: Bernd Walter <ticso@cicely7.cicely.de> To: FreeBSD-arm@freebsd.org Cc: Bernd Walter <ticso@cicely7.cicely.de> Subject: Re: TFT Panel trouble with Raspi Message-ID: <20130225023041.GB39037@cicely7.cicely.de> In-Reply-To: <20130221041011.GB12189@cicely7.cicely.de> References: <20130221041011.GB12189@cicely7.cicely.de>
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On Thu, Feb 21, 2013 at 05:10:12AM +0100, Bernd Walter wrote: > I'm using the folloging Image: > http://www.peach.ne.jp/archives/rpi/freebsd-pi-clang-20130210.img.gz > With this Panel: > http://www.chalk-elec.com/?page_id=1280#!/~/product/category=3094861&id=14647630 > > Resolution is 1024x600 pixel with an HDMI adapter. > > Under Linux at first it didn't display anything at all. > The following config.txt was required: > hdmi_ignore_edid=0xa5000080 > hdmi_group=2 > hdmi_mode=16 > overscan_top=-40 > overscan_bottom=125 > > This sets 1024x768 and tunes overscan area. > Nice HDMI crap only knows defined resolutions... > Without overscan values the display starts at the right top postion, but > the 168 excessive bottom lines are missing on display - no surprise. > Descriptions claims those to be pixels, so those values don't make 100% > sense to me as math says the result to be 683 pixel, but basicly the > result looks good. > Considering the description it doesn't make sense to tamper with top > values as it is correctly aligned without overscan. > > With FreeBSD however those values won't work. > The result is that at top there is empty space and missing lines at > the bottom. > If I set 800x600 resolution everything looks good, but width isn't used > completely. > With description I would assume that setting bottom to 168 should give > the right result, but setting bottom to 168 cuts 84 lines at > bottom and 84 lines at top. > With bottom to 336 the bottom is alligned correctly but missing 168 > lines on top. > With bottom to 336 and top to -168 the result is the same as with > bottom at 168 and top at 0. > > Under Linux the result is different. > Setting bottom to 168 cuts many more pixel at bottom and less pixel > at top - sigh, so much about their documentation. > I would guess it cuts about 3x at bottom and 1x at top. > Adding top=-10 seems to add symetrical pixel at top and bottom. > Strange enough - booting Linux with the above vendor supplied config > shows this: > [ 0.000000] Kernel command line: dma.dmachans=0x7f35 bcm2708_fb.fbwidth=1024 bcm2708_fb.fbheight=683 bcm2708.boardrev=0x3 bcm2708.serial=0xda48bc18 smsc95xx.macaddr=B8:27:EB:48:BC:18 sdhci-bcm2708.emmc_clock_freq=100000000 vc_mem.mem_base=0xec00000 vc_mem.mem_size=0x10000000 dwc_otg.lpm_enable=0 console=ttyAMA0,115200 kgdboc=ttyAMA0,115200 console=tty1 root=/dev/mmcblk0p2 rootfstype=ext4 elevator=deadline rootwait > fbheigh = 683, but I would say that I would have noticed 83 missing > pixels, although it agrees with my math about those values to be pixels. > > Btw - on my LG TV with 1366x768 pixel (it announces as 1360x768 and > scales to 1366 sigh) FreeBSD was missing bottom lines as well. > I know because I plugged it into my TV to boot the FreeBSD for the first > time, didn't get a login and thought there was only a getty running on > serial console. > I didn't debug there any further. > Today with the TFT-Panel I saw that it is indeed running a getty. > Whatever bad magic there is - Linux knows it and FreeBSD has problems. This point was wrong. Everthing looks Ok on the LG TV. But setting overscan_bottom also reduces same amount of pixel on top as on bottom and not just at the bottom as expected. -- B.Walter <bernd@bwct.de> http://www.bwct.de Modbus/TCP Ethernet I/O Baugruppen, ARM basierte FreeBSD Rechner uvm.
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