Linux/AM3354: Prevent Cursor appears in framebuffer display

Mao zhulin

Hi,

I am using the buildroot to compile the linux kernel 5.15.86.

And I found there is a cursor flashing on the LCD. So I want to prevent the cursor by disable framebuffer console.

But after me disable the configure: CONFIG_FRAMEBUFFER_CONSOLE. The LCD can't work. Nothing display, except some White vertical line.

I'm following the guide: https://software-dl.ti.com/processor-sdk-linux/esd/docs/latest/linux/Foundational_Components/Kernel/Kernel_Drivers/Display/LCDC.html

Using DRM framework:

And my DRM configure is

#
# Graphics support
#
# CONFIG_IMX_IPUV3_CORE is not set
CONFIG_DRM=y
CONFIG_DRM_DP_AUX_BUS=y
# CONFIG_DRM_DP_AUX_CHARDEV is not set
# CONFIG_DRM_DEBUG_MM is not set
# CONFIG_DRM_DEBUG_SELFTEST is not set
CONFIG_DRM_KMS_HELPER=y
# CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS is not set
CONFIG_DRM_FBDEV_EMULATION=y
CONFIG_DRM_FBDEV_OVERALLOC=100
# CONFIG_DRM_FBDEV_LEAK_PHYS_SMEM is not set
# CONFIG_DRM_LOAD_EDID_FIRMWARE is not set
# CONFIG_DRM_DP_CEC is not set
CONFIG_DRM_GEM_CMA_HELPER=y
CONFIG_DRM_KMS_CMA_HELPER=y

#
# I2C encoder or helper chips
#
# CONFIG_DRM_I2C_CH7006 is not set
# CONFIG_DRM_I2C_SIL164 is not set
# CONFIG_DRM_I2C_NXP_TDA998X is not set
# CONFIG_DRM_I2C_NXP_TDA9950 is not set
# end of I2C encoder or helper chips

#
# ARM devices
#
# CONFIG_DRM_HDLCD is not set
# CONFIG_DRM_MALI_DISPLAY is not set
# CONFIG_DRM_KOMEDA is not set
# end of ARM devices

# CONFIG_DRM_VGEM is not set
# CONFIG_DRM_VKMS is not set
# CONFIG_DRM_EXYNOS is not set
# CONFIG_DRM_UDL is not set
# CONFIG_DRM_ARMADA is not set
# CONFIG_DRM_RCAR_DW_HDMI is not set
# CONFIG_DRM_RCAR_LVDS is not set
# CONFIG_DRM_OMAP is not set
CONFIG_DRM_TILCDC=y
# CONFIG_DRM_VIRTIO_GPU is not set
# CONFIG_DRM_FSL_DCU is not set
# CONFIG_DRM_STM is not set
CONFIG_DRM_PANEL=y

#
# Display Panels
#

CONFIG_DRM_PANEL_SIMPLE=y

If I enable the CONFIG_FRAMEBUFFER_CONSOLE. The display work well.

If I disable the CONFIG_FRAMEBUFFER_CONSOLE, The display can't work.

I am hoping someone can suggest how I might track this down, and then hopefully disable it in the systemd startup scripts

Thanks for any suggestions.
Best regards,
Richard

over 2 years ago

0 Krunal Bhargav34 over 2 years ago

TI__Mastermind 44675 points

Hello,

Are you by any chance using a window compositor that uses fbdev? In the past, I worked with a customer who disabled CONFIG_FRAMEBUFFER_CONSOLE and his display worked fine after removing the FRAMEBUFFER_CONSOLE: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1130792/am625-how-to-disable-the-booting-display-layer/4200447?tisearch=e2e-sitesearch&keymatch=fbdev#4200447.

Also, I am not familiar with your filesystem but I know on our SDK we run Weston. The Weston framework only enumerates mouse cursor if a USB mouse is detected.

Regards,
Krunal

0 Mao zhulin over 2 years ago in reply to Krunal Bhargav34

Prodigy 10 points

Hello.

Thanks for support.

It is a mini system, compiled by buildroot. Only busybox and kernel.

And I have enable the logo.

CONFIG_LOGO=y
CONFIG_LOGO_LINUX_MONO=y
CONFIG_LOGO_LINUX_VGA16=y
CONFIG_LOGO_LINUX_CLUT224=y

But I can't found the penguin. And I try to cat sunflower.bmp >/dev/fb0. But can't work.

0 Krunal Bhargav34 over 2 years ago in reply to Mao zhulin

TI__Mastermind 44675 points

We don't support fbdev and you may need to check with the community on the cursor issue. The CONFIG_FRAMEBUFFER_CONSOLE is related to fbdev and it makes sense why the display stops working if it's disabled.

Regards,
Krunal

0 Mao zhulin over 2 years ago in reply to Krunal Bhargav34

Prodigy 10 points

Hello.

Thanks for your support.

So, is there method to display the penguin logo in boot screen when disable the CONFIG_FRAMEBUFFER_CONSOLE?

Like,

#
# Console display driver support
#
CONFIG_DUMMY_CONSOLE=y
# CONFIG_FRAMEBUFFER_CONSOLE is not set
# end of Console display driver support

Thanks very much.

0 Krunal Bhargav34 over 2 years ago in reply to Mao zhulin

TI__Mastermind 44675 points

The penguin logo/psplash animation uses fbdev framework and I am not familiar with a solution that is based on the DRM framework. We simply inherited a solution that was provided by the community to demonstrate a proof of concept.

Regards,
Krunal

0 Mao zhulin over 2 years ago in reply to Krunal Bhargav34

Prodigy 10 points

OK， Thanks your support.

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Linux/AM3354: Prevent Cursor appears in framebuffer display