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Kernel/Graphics: Disable double buffering for the VirtIO driver

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The performance that we achieve from this technique is visually worse
compared to turning off this feature, so let's not use this until we
figure out why it happens.
This commit is contained in:
Liav A 2022-12-16 15:37:32 +02:00 • committed by Sam Atkins
parent bb491a681d
commit 12d4bbbd11
3 changed files with 12 additions and 28 deletions
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34
Kernel/Graphics/VirtIOGPU/DisplayConnector.cpp
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@ -96,16 +96,13 @@ ErrorOr<void> VirtIODisplayConnector::set_safe_mode_setting()
return set_mode_setting(safe_mode_setting);
}
ErrorOr<void> VirtIODisplayConnector::set_y_offset(size_t y)
ErrorOr<void> VirtIODisplayConnector::set_y_offset(size_t)
{
VERIFY(m_control_lock.is_locked());
if (y == 0)
m_last_set_buffer_index.store(0);
else if (y == m_display_info.rect.height)
m_last_set_buffer_index.store(1);
else
return Error::from_errno(EINVAL);
return {};
// NOTE (FIXME?): We don't do double buffering because when using double buffering,
// perfomance visually looks terrible (everything look sluggish) compared to not using it,
// so until we figure out why (and we might not figure this and double buffering is simply not needed)
// this happens, we simply don't support it.
return Error::from_errno(ENOTSUP);
}
ErrorOr<void> VirtIODisplayConnector::unblank()
{
@ -125,14 +122,9 @@ ErrorOr<void> VirtIODisplayConnector::flush_rectangle(size_t buffer_index, FBRec
.height = rect.height
};
bool main_buffer = (buffer_index == 0);
m_graphics_adapter->transfer_framebuffer_data_to_host({}, *this, dirty_rect, main_buffer);
if (m_last_set_buffer_index.load() == buffer_index) {
// Flushing directly to screen
flush_displayed_image(dirty_rect, main_buffer);
} else {
set_dirty_displayed_rect(dirty_rect, main_buffer);
}
m_graphics_adapter->transfer_framebuffer_data_to_host({}, *this, dirty_rect, true);
// Flushing directly to screen
flush_displayed_image(dirty_rect, true);
return {};
}
@ -147,13 +139,9 @@ ErrorOr<void> VirtIODisplayConnector::flush_first_surface()
.height = m_display_info.rect.height
};
auto current_buffer_index = m_last_set_buffer_index.load();
VERIFY(is_valid_buffer_index(current_buffer_index));
bool main_buffer = (current_buffer_index == 0);
m_graphics_adapter->transfer_framebuffer_data_to_host({}, *this, dirty_rect, main_buffer);
m_graphics_adapter->transfer_framebuffer_data_to_host({}, *this, dirty_rect, true);
// Flushing directly to screen
flush_displayed_image(dirty_rect, main_buffer);
flush_displayed_image(dirty_rect, true);
return {};
}