File 0013-Disable-timer-check-in-file-loading.patch of Package u-boot

From ed8ce5f441b3f1d93826c964695f61137769e5d4 Mon Sep 17 00:00:00 2001
From: Michael Chang <mchang@suse.com>
Date: Tue, 25 May 2021 06:45:01 +0000
Subject: [PATCH] Disable timer check in file loading

The u-boot efi console service registers a timer to poll the keyboard
input in every 50ns. In the efi block io service, this timer is
evaluated on each block read, and since the timer interval is much less
than the time needed to reading out a block (32kB) from the disk, the
keyboard polling is therefore in the wake of each block read.

Unfortunately USB keyboard spends too much time in polling. In my test
usb_kbd_poll_for_event costs 40ms in usb_kbd_testc() to test if a
character is in the queue. In combination with the number of blocks to
be read from the disk, the extra amound of time delayed could be around
30 seconds to load linux and initrd.

For that matters, the timer check is disabled in file loading to speed
it up. The consequence would be losing the keystroke during the time
file is loading, but that is acceptable IMHO.

Signed-off-by: Matthias Brugger <mbrugger@suse.com>
---
 lib/efi_loader/efi_disk.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/efi_loader/efi_disk.c b/lib/efi_loader/efi_disk.c
index 5452640354e..0fd1682c53c 100644
--- a/lib/efi_loader/efi_disk.c
+++ b/lib/efi_loader/efi_disk.c
@@ -18,6 +18,7 @@
 #include <log.h>
 #include <part.h>
 #include <malloc.h>
+#include <watchdog.h>
 
 struct efi_system_partition efi_system_partition = {
 	.uclass_id = UCLASS_INVALID,
@@ -136,8 +137,7 @@ static efi_status_t efi_disk_rw_blocks(struct efi_block_io *this,
 			n = blk_dwrite(desc, lba, blocks, buffer);
 	}
 
-	/* We don't do interrupts, so check for timers cooperatively */
-	efi_timer_check();
+	schedule();
 
 	EFI_PRINT("n=%lx blocks=%x\n", n, blocks);