Some bug-like issues about lv_port_linux

[pan1024]

I got this error "[Error] (4292956.517, [phone]) lv_display_set_buffers: Asserted at expression: stride * h <= buf_size DIRECT mode requires screen sized buffer(s) lv_display.c:419"

[pan1024]

I don't know how to set this due to the change of interface, but I found LV_LINUX_FBDEV_BUFFER_SIZE in lv_config.h and set it to my screen size (480*480) but this is invalid and I still get that error.

[pan1024]

Until I found out about this
lv_display_t * lv_linux_fbdev_create(void)
{
static bool inited = false;
if(!inited) {
lv_tick_set_cb(tick_get_cb),
inited = true;
}

lv_linux_fb_t * dsc = lv_malloc_zeroed(sizeof(lv_linux_fb_t));
LV_ASSERT_MALLOC(dsc);
if(dsc == NULL) return NULL;

lv_display_t * disp = lv_display_create(800, 480);
if(disp == NULL) {
    lv_free(dsc);
    return NULL;
}
dsc->fbfd = -1;
lv_display_set_driver_data(disp, dsc);
lv_display_set_flush_cb(disp, flush_cb);

return disp;

}
Maybe you found the problem, lv_display_t * disp = lv_display_create(800, 480); When I modify it to lv_display_t * disp = lv_display_create(480, 480); The program is ready to run, and I found the same problem in the DRM code

[pan1024]

As I continued reading the source code, I found this
if(LV_LINUX_FBDEV_RENDER_MODE == LV_DISPLAY_RENDER_MODE_PARTIAL) {
draw_buf_size *= LV_LINUX_FBDEV_BUFFER_SIZE;}
However, there is no LV_DISPLAY_RENDER_MODE_PARTIAL in lv_conf.h, and perhaps more details are needed to refine the use of the new version

[kisvegabor]

Hi,

Can you send a code snippet to reproduce the issue with

• how you create the display
• the FBDEV related part of lv_conf.h

[pan1024]

Hi,

Can you send a code snippet to reproduce the issue with

• how you create the display
• the FBDEV related part of lv_conf.h

I didn't make any changes to the project after I got it, I put it on my board after cross-compiling it according to the README, at this point I was already wondering why there was no screen configuration similar to v8.3, and then the error I mentioned occurred at runtime

[pan1024]

Hi,
Can you send a code snippet to reproduce the issue with

• how you create the display
• the FBDEV related part of lv_conf.h

I didn't make any changes to the project after I got it, I put it on my board after cross-compiling it according to the README, at this point I was already wondering why there was no screen configuration similar to v8.3, and then the error I mentioned occurred at runtime

lv_display_t * lv_linux_fbdev_create (void) It comes from lvgl/src/drivers/display/fb

[kisvegabor]

Please print dsc->vinfo.bits_per_pixel.

[pan1024]

Please print dsc->vinfo.bits_per_pixel.
dsc->vinfo.bits_per_pixel:32

[pan1024]

Please print dsc->vinfo.bits_per_pixel.

I'm not sure you understand what I mean, but I mean from the main.c example so far lv_linux_fbdev_create the (void) design may not be flexible enough, and when I want to change the screen size, I need to go into the source code to modify it, if there is an easier way, please let me know

[kisvegabor]

what I mean, but I mean from the main.c example so far lv_linux_fbdev_create the (void) design may not be flexible enough, and when I want to change the screen size, I need to go into the source code to modify it, if there is an easier way, please let me know

Oh, I really misunderstood it and it's really set the the screen's resolution by default. What we can do is calling lv_display_set_resolution(display, hor_res, ver_res) from main.c but in lv_linux_fbdev_create we can add an LV_EVENT_RESOLUTION_CHANGED event to the display where we can reallocate the buffers.