fbcon bug?

DISCUSSION Zack Smith 3 participants 5 messages Nov 14, 2005 – Nov 15, 2005 Framebuffer layer

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Zack Smith

author

2005-11-14 02:24 UTC #0 lore raw

Hi all,

I've noticed that 2.6.14, when a console switch occurs going from a console that is KD_TEXT to one that is KD_GRAPHICS, fbcon doesn't seem to immediately shut down the cursor. It appears to draw or undraw the cursor at least once before it disables cursor activity due to graphics mode.

Does anybody know if this bug has been corrected in 14.1 or .2, or if anyone would mind if I go in and fix it?

Thanks,
Zack Smith

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Ville Syrjälä

2005-11-14 19:13 UTC #1 lore raw

Quoted 10 lines · Zack Smith

Hi all,
I've noticed that 2.6.14, when a console switch occurs going from a console that is KD_TEXT to one that is KD_GRAPHICS, fbcon doesn't seem to immediately shut down the cursor. It appears to draw or undraw the cursor at least once before it disables cursor activity due to graphics mode.
Does anybody know if this bug has been corrected in 14.1 or .2, or if anyone would mind if I go in and fix it?

I'm not sure if it's related but there is a cursor problem with atyfb. When doing ioctl(... KD_GRAPHICS) the cursor remains visible in most cases. Sometimes it does disappear properly but that is quite rare. However doing a vt switch to another vt and back again seems to fix it every time so I'm not sure it's the same problem you're seeing. None of the other fb drivers I use implement a hardware cursor which is probably the reason I'm only seeing it on atyfb.

Signature · 10 lines

Ville Syrjälä
[email protected]
http://www.sci.fi/~syrjala/


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Antonino A. Daplas

2005-11-14 20:11 UTC #2 lore raw

Quoted 12 lines · Ville Syrjälä

Quoted 10 lines · Zack Smith
Hi all,
I've noticed that 2.6.14, when a console switch occurs going from a console that is KD_TEXT to one that is KD_GRAPHICS, fbcon doesn't seem to immediately shut down the cursor. It appears to draw or undraw the cursor at least once before it disables cursor activity due to graphics mode.
Does anybody know if this bug has been corrected in 14.1 or .2, or if anyone would mind if I go in and fix it?

Quoted 8 lines

I'm not sure if it's related but there is a cursor problem with atyfb. When doing ioctl(... KD_GRAPHICS) the cursor remains visible in most cases. Sometimes it does disappear properly but that is quite rare. However doing a vt switch to another vt and back again seems to fix it every time so I'm not sure it's the same problem you're seeing. None of the other fb drivers I use implement a hardware cursor which is probably the reason I'm only seeing it on atyfb.

Once the console is in KD_GRPHICS mode, all access the to the framebuffer are essentially stopped. So depending on the state of the cursor (visible or not), it will stay that way even if a command to erase or draw the cursor is given.

You may tell the console to erase the cursor before going to KD_GRAPHICS mode as a workaround.

Tony

Zack Smith

author

2005-11-15 00:21 UTC #3 lore raw

Quoted 1 line · Antonino A. Daplas

Once the console is in KD_GRPHICS mode, all access the to the framebuffer are essentially stopped.

What I'm seeing is that after a console switch to a KD_GRAPHICS console (call it A) from a KD_TEXT console (console B), B's cursor is seemingly undrawn in A. Basically, wherever the cursor was B, that's where you will see a black box drawn in A, and there is a delay in its being drawn.

Zack

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Antonino A. Daplas

2005-11-15 00:51 UTC #4 lore raw

Quoted 10 lines · Zack Smith

Quoted 2 lines · Antonino A. Daplas
Once the console is in KD_GRPHICS mode, all access the to the framebuffer are essentially stopped.
What I'm seeing is that after a console switch to a KD_GRAPHICS console (call it A)
from a KD_TEXT console (console B), B's cursor is seemingly undrawn in A. Basically, wherever the cursor was B, that's where you will see a black box drawn in A,
and there is a delay in its being drawn.

Strange. If you can trace why this is happening, that will be helpful.

Note that vt.c also has it's own softcursor (it uses con->putc), which sometimes run in parallel with fbcon's cursor so you might want to check that also.

Tony