There is no picture in lcd

SGaist

Did you check the permissions on the frame buffer device ?

On a side note, if locked on Qt 4, the you should go with 4.8.7 which is the latest and last version of the Qt 4 series. Otherwise, you should go with Qt 5.

junzhang

@SGaist
here is my cross compile config:
sudo ./configure --prefix=/usr/local/qt4.8.5-arm -opensource -release -shared -Declarative -importdir /opt/imports -fast -no-largefile -qt-sql-sqlite -qt3support -exceptions -xmlpatterns -no-glib -no-phonon -no-mmx -no-3dnow -no-sse -no-sse2 -svg -no-webkit -qt-zlib -qt-libtiff -qt-libpng -qt-libjpeg -make libs -make tools -nomake examples -nomake docs -nomake demo -no-nis -no-cups -iconv -no-dbus -xplatform qws/linux-arm-g++ -embedded arm -little-endian -qt-freetype -depths 16,24,32 -qt-gfx-linuxfb -qt-gfx-transformed -qt-gfx-multiscreen -no-gfx-vnc -no-gfx-qvfb -qt-kbd-linuxinput -no-kbd-qvfb -armfpa -no-mouse-qvfb -qt-mouse-linuxtp -qt-mouse-tslib -DQT_QLOCALE_USES_FCVT -DQT_NO_QWS_CURSOR -no-pch -I/usr/local/tslib/include -L/usr/local/tslib/lib -confirm-license

SGaist

That doesn't answer my question about the permissions of /dev/fb0 on your target.

On a side note, never develop nor build as root. If something goes wrong there's no restriction at what can be destroyed on your system.

junzhang

@SGaist
/ # ls /dev/fb0 -l
crw-rw---- 1 root root 29, 0 Jan 1 00:00 [1;35m/dev/fb0

when l use Qt/qt/qt-everywhere-opensource-src-4.8.5/examples/qws/framebuffer to test, it's ok,
your mean it's maybe to compile use "sudo"?
l will re-compile it with no "sudo".

SGaist

How are you calling your application on the command line ?

junzhang

@SGaist
./test_demo -qws

junzhang

@SGaist
l use normal user to cross compile qt5.7.0, it's still unshow anything unless l add "ioctl(fbFd, FBIOGET_FSCREENINFO, &finfo)".and it just to show one frame,
my cross compile steps is below:

download tslib1.4.tar.gz$ ./autogen.sh
$ tar zxvf tslib1.4.tar.gz
$ ./configure CC=arm-none-linux-gnueabihf-gcc CXX=arm-none-linux-gnueabihf-g++ --prefix=/usr/local/tslib --host=arm-none-linux-gnueabihf ac_cv_func_malloc_0_nonnull=yes
$make
$sudo make install
download qt-everywhere-opensource-src-5.7.0.tar.gz
2.1: tar zxvf qt-everywhere-opensource-src-5.7.0.tar.gz
2.2: vim qt-everywhere-opensource-src-5.7.0/qtbase/mkspecs/linux-arm-gnueabi-g++/qmake.conf
```
 include(../common/linux.conf)
+ QT_QPA_DEFAULT_PLATFORM = linux #eglfs 
+QMAKE_CFLAGS_RELEASE += -O2 -march=armv7-a
+ QMAKE_CXXFLAGS_RELEASE += -O2 -march=armv7-a
```
arm-linux-geneabi-xxx change to arm-none-linux-geneabi-xxx
2.3: vim build.sh

#!/bin/sh
./configure
-v
-prefix /opt/qt5.7.0
-release
-opensource
-make libs
-xplatform linux-arm-gnueabi-g++
-optimized-qmake
-pch
-qt-sql-sqlite
-qt-libjpeg
-qt-zlib
-no-opengl
-skip qt3d
-skip qtcanvas3d
-skip qtpurchasing
-no-sse2
-no-openssl
-no-nis
-no-cups
-no-glib
-no-iconv
-nomake examples
-nomake tools
-skip qtvirtualkeyboard
-I/usr/local/tslib/include
-L/usr/local/tslib/lib

exit
2.4: ./build.sh
2.5: make
2.6: sudo make install
tar /usr/local/tslib and /opt/qt5.7.0
for arm platform
4.1: cp qt5.7.0.tar.gz and tslib.tar.gz to /opt
4.2: tar zxvf qt5.7.0.tar.gz and tar zxvf tslib.tar.gz
4.3: vim /etc/profile
#add for qt
export TSLIB_ROOT=/opt/tslib
export QT_ROOT=/opt/qt5.7.0
export TSLIB_TSDEVICE=/dev/input/event0
export TSLIB_TSEVENTTYPE=input
export TSLIB_CONFFILE=/opt/tslib/etc/ts.conf
export TSLIB_CALIBFILE=/etc/pointercal
export TSLIB_PLUGINDIR=/opt/tslib/lib/ts
export TSLIB_CONSOLEDEVICE=none
export TSLIB_FBDEVICE=/dev/fb0
export QWS_MOUSE_PROTO=tslib:/dev/input/event0
export LD_LIBRARY_PATH=/lib:/usr/lib:$QT_ROOT/lib:$TSLIB_ROOT/lib:$TSLIB_ROOT/lib/
export QT_QPA_PLATFORM_PLUGIN_PATH=$QT_ROOT/plugins
export QT_QPA_PLATFORM=linuxfb:tty=/dev/fb0
export QT_QPA_FONTDIR=$QT_ROOT/lib/fonts
export QT_QPA_GENERIC_PLUGINS=tslib
4.4: source /etc/profile
4.5: cd /opt/tslib/bin and then run ./ts_calibrate
4.6: write an test example
qmake test_qt.pro
make
adb push test_qt /home/demo
4.6: cd /home/demo and then ./test_qt

after l run ./test_qt, there is nothing in lcd,so l write test framebuffer code to test fb driver, it's show ok,
but if l add "ioctl(fbFd, FBIOPAN_DISPLAY, &vinfo)" in test_qt demo, it's show ok, but it just show one frame, unable to self-refresh,

for step 4.5 and 4.6, l use another method to test, but there is still nothing in lcd.
4.5: ./ts_calibrate -qws
4.6: ./test_qt -qws

note: there is no touch screen in my whole steps.

SGaist

What OS are you running on your target ?

junzhang

@SGaist
/ # uname -a
uname -a
Linux mdm9607 3.18.20 #1 PREEMPT Mon Feb 13 10:40:15 CST 2017 armv7l GNU/Linux
/ #

SGaist

The distribution would be more useful.

Also, are you running your application as root ?

What exact message are you getting on the console when you launch the application ?

junzhang

@SGaist
yes, we run an application with root access.
we test with Qt/examples/qws/framebuffer, the message is below:

root@mdm9607:/home# ./framebuffer
./framebuffer
The framebuffer device was opened successfully.

Fixed screen info:
id: mdssfb_20000
smem_start: 0x8fc80000
smem_len: 155648
type: 0
type_aux: 0
visual: 2
xpanstep: 1
ypanstep: 1
ywrapstep: 0
line_length: 480
mmio_start: 0x0
mmio_len: 0
accel: 0

The framebuffer device was mapped to memory successfully.

Successfully switched to graphics mode.

Variable screen info:
xres: 240
yres: 320
xres_virtual: 240
yres_virtual: 320
yoffset: 0
xoffset: 0
bits_per_pixel: 16
grayscale: 0
red: offset: 11, length: 5, msb_right: 0
green: offset: 5, length: 6, msb_right: 0
blue: offset: 0, length: 5, msb_right: 0
transp: offset: 0, length: 0, msb_right: 0
nonstd: 0
activate: 16
height: -1
width: -1
accel_flags: 0x0
pixclock: 0
left_margin: 0
right_margin: 0
upper_margin: 0
lower_margin: 0
hsync_len: 0
vsync_len: 0
sync: 0
vmode: 0

Frame Buffer Performance test...
Average: 395 usecs
Bandwidth: 375.791 MByte/Sec
Max. FPS: 2531.646 fps

Will draw 3 rectangles on the screen,
they should be colored red, green and blue (in that order).
Done.
root@mdm9607:/home#

l change the Qt/examples/qws/framebuffer/main.c
void drawRect_rgb16(int x0, int y0, int width, int height, int color)
{
const int bytesPerPixel = 2;
const int stride = finfo.line_length / bytesPerPixel;
const int red = (color & 0xff0000) >> (16 + 3);
const int green = (color & 0xff00) >> (8 + 2);
const int blue = (color & 0xff) >> 3;
const short color16 = blue | (green << 5) | (red << (5 + 6));

short *dest = (short*)(frameBuffer)
	  + (y0 + vinfo.yoffset) * stride
	  + (x0 + vinfo.xoffset);

int x, y;
for (y = 0; y < height; ++y) {
    for (x = 0; x < width; ++x) {
        dest[x] = color16;
    }
    dest += stride;
}//add by junzhang
if(ioctl(fbFd, FBIOPAN_DISPLAY, &vinfo)!= 0)
{
    return -1;
}//

}
there is nothing in lcd unless l add that code when l test with framebuffer example, the message is the same whether l add that code or not.

junzhang

@SGaist
l want to add
if(ioctl(fbFd, FBIOPAN_DISPLAY, &vinfo)!= 0)
{
return -1;
}/
to the code which update framebuffer in Qt,
it's mean that if something update in Qt, it will be write data to framebuffer, so, i will add that code in the function which update framebuffer.
it's that ok?
if ok, pls tell which function update framebuffer. thx.

SGaist

You likely should check the QLinuxFbScreen class.

junzhang

@SGaist
thx, l found it and it's show ok.

SGaist

Do you mean by adding you ioctl code ?

junzhang

@SGaist
yes, l add inctl to refresh data to lcd.

SGaist

Ok

Then please mark the thread as solved using the "Topic Tools" button so that other forum users may know a solution has been found :)