[openwrt/openwrt] kernel: enable SERIAL_8250_16550A_VARIANTS

[LEDE Commits]

stintel pushed a commit to openwrt/openwrt.git, branch master:
https://git.openwrt.org/4ecf8346c074ff80101a17d39086010f8f4b23b8

commit 4ecf8346c074ff80101a17d39086010f8f4b23b8
Author: Stijn Tintel <stijn at linux-ipv6.be>
AuthorDate: Mon Mar 14 21:56:55 2022 +0200

    kernel: enable SERIAL_8250_16550A_VARIANTS
    
    Kernel 5.6 introduced a new config symbol SERIAL_8250_16550A_VARIANTS.
    In kernel 5.8, this symbol was changed to default to on on !x86, as some
    embedded devices still use 16650A variants. Let's play safe here and
    enable this symbol in the generic config, to avoid others from running
    into this problem and having to spend several hours trying to bisect
    this problem. While we could disable the symbol in the x86 target
    configs, a 20ms boot time reduction really isn't worth the time wasted
    on bisecting this issue.
    
    Matt discovered this problem while working on adding support for the
    WatchGuard Firebox M200 to the qoriq target, where it caused some
    characters to be missing on the console output.
    
    Reported-by: Matt Fawcett <mattytap at icloud.com>
    Signed-off-by: Stijn Tintel <stijn at linux-ipv6.be>
    Reviewed-by: Rui Salvaterra <rsalvaterra at gmail.com>
---
 target/linux/generic/config-5.10 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/target/linux/generic/config-5.10 b/target/linux/generic/config-5.10
index 191566b0b8..3622901a87 100644
--- a/target/linux/generic/config-5.10
+++ b/target/linux/generic/config-5.10
@@ -5314,7 +5314,7 @@ CONFIG_SELECT_MEMORY_MODEL=y
 # CONFIG_SENSORS_XGENE is not set
 # CONFIG_SENSORS_ZL6100 is not set
 CONFIG_SERIAL_8250=y
-# CONFIG_SERIAL_8250_16550A_VARIANTS is not set
+CONFIG_SERIAL_8250_16550A_VARIANTS=y
 # CONFIG_SERIAL_8250_ACCENT is not set
 # CONFIG_SERIAL_8250_ASPEED_VUART is not set
 # CONFIG_SERIAL_8250_BOCA is not set