Hi Marek,
On Thu, 10 Feb 2022 at 14:42, Marek Vasut marex@denx.de wrote:
On 2/10/22 22:13, Thomas Watson wrote:
Using the XHCI driver, the function `usb_kbd_poll_for_event` takes 30-40ms to run. The exact time is dependent on the polling interval the keyboard requests in its descriptor, and likely cannot be significantly reduced without major rework to the XHCI driver.
The U-Boot EFI console service sets a timer to poll the keyboard every 5 microseconds, and this timer is checked every time a block is read off disk. The net effect is that, on my system, loading a ~40MiB kernel and initrd takes about 62 seconds with a slower keyboard and 53 seconds with a faster one, with the vast majority of the time spent polling the keyboard.
To solve this problem, this patch adds a 20ms delay between consecutive calls to `usb_kbd_poll_for_event`. This is sufficient to reduce the total loading time to under half a second for both keyboards, and does not impact the perceived keystroke latency.
Signed-off-by: Thomas Watson twatson52@icloud.com
This revision fixes a sandbox test failure by honoring the test's request to skip delays.
common/usb_kbd.c | 31 ++++++++++++++++++++++++++----- 1 file changed, 26 insertions(+), 5 deletions(-)
We don't want to delay the CI tests which take enough time as it is. So time needs to be faked.
It could be an if() though, rather than #if, perhaps?
Regards, Simon