openwrt/package/boot/uboot-mediatek/patches/010-menu-fix-the-logic-checking-whether-ESC-key-is-press.patch

From 72b4ba8417d33516b8489bac3c90dbbbf781a3d2 Mon Sep 17 00:00:00 2001
From: Weijie Gao <weijie.gao@mediatek.com>
Date: Tue, 29 Oct 2024 17:47:10 +0800
Subject: [PATCH 1/3] menu: fix the logic checking whether ESC key is pressed

It's observed that the bootmenu on a serial console sometimes
incorrectly quitted with superfluous characters filled to command
line input:

>  *** U-Boot Boot Menu ***
>
>      1. Startup system (Default)
>      2. Upgrade firmware
>      3. Upgrade ATF BL2
>      4. Upgrade ATF FIP
>      5. Load image
>      0. U-Boot console
>
>
>  Press UP/DOWN to move, ENTER to select, ESC to quit
>MT7988> [B

Analysis shows it was caused by the wrong logic of bootmenu_loop:

At first the bootmenu_loop received the first ESC char correctly.

However, during the second call to bootmenu_loop, there's no data
in the UART Rx FIFO. Due to the low baudrate, the second char of
the down array key sequence hasn't be fully received.

But bootmenu_loop just did a mdelay(10), and then treated it as a
single ESC key press event. It didn't even try tstc() again after
the 10ms timeout.

This patch fixes this issue by letting bootmenu_loop check tstc()
twice.

Tested-By: E Shattow <lucent@gmail.com>
Signed-off-by: Weijie Gao <weijie.gao@mediatek.com>
---
 common/menu.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/common/menu.c
+++ b/common/menu.c
@@ -525,14 +525,15 @@ enum bootmenu_key bootmenu_loop(struct b
 				struct cli_ch_state *cch)
 {
 	enum bootmenu_key key;
-	int c;
+	int c, errchar = 0;
 
 	c = cli_ch_process(cch, 0);
 	if (!c) {
 		while (!c && !tstc()) {
 			schedule();
 			mdelay(10);
-			c = cli_ch_process(cch, -ETIMEDOUT);
+			c = cli_ch_process(cch, errchar);
+			errchar = -ETIMEDOUT;
 		}
 		if (!c) {
 			c = getchar();