diff options
author | Hans de Goede <hdegoede@redhat.com> | 2015-05-05 13:13:36 +0200 |
---|---|---|
committer | Hans de Goede <hdegoede@redhat.com> | 2015-05-19 18:37:30 +0200 |
commit | a8552c7c9b53d1d4f36b95f2c80812d8a7bb4fff (patch) | |
tree | 72406ed8d3ee56813c595d837ec69864e0ee8df3 /api/api_display.c | |
parent | f9b08fbf11add614f1773c5378a9026cd3d5c75f (diff) | |
download | u-boot-imx-a8552c7c9b53d1d4f36b95f2c80812d8a7bb4fff.zip u-boot-imx-a8552c7c9b53d1d4f36b95f2c80812d8a7bb4fff.tar.gz u-boot-imx-a8552c7c9b53d1d4f36b95f2c80812d8a7bb4fff.tar.bz2 |
console: Fix pre-console flushing via cfb_console being very slow
On my A10 OlinuxIno Lime I noticed a huge (5+ seconds) delay coming from
console_init_r. This turns out to be caused by the preconsole buffer flushing
to the cfb_console. The Lime only has a 16 bit memory bus and that is already
heavy used to scan out the 1920x1080 framebuffer.
The problem is that print_pre_console_buffer() was printing the buffer once
character at a time and the cfb_console code then ends up doing a cache-flush
for touched display lines for each character.
This commit fixes this by first building a 0 terminated buffer and then
printing it in one puts() call, avoiding unnecessary cache flushes.
This changes the time for the flush from 5+ seconds to not noticable.
The downside of this approach is that the pre-console buffer needs to fit
on the stack, this is not that much to ask since we are talking about plain
text here. This commit also adjusts the sunxi CONFIG_PRE_CON_BUF_SZ to
actually fit on the stack. Sunxi currently is the only user of the pre-console
code so no other boards need to be adjusted.
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Diffstat (limited to 'api/api_display.c')
0 files changed, 0 insertions, 0 deletions