This looks like a typo. By manipulating the antenna on a device while
monitoring the reported SNR, I was able to see the unexpected jump.
After applying this patch, the spike was no longer present.
Link: https://lore.kernel.org/linux-media/20211003001805.735092-1-logans@cottsay.net
Signed-off-by: Scott K Logan <logans@cottsay.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
        {  0x35b, 235, },
        {  0x353, 230, },
        {  0x349, 225, },
-       {  0x340, 320, },
+       {  0x340, 220, },
        {  0x337, 215, },
        {  0x327, 210, },
        {  0x31b, 205, },