Kernel: 不列入git log的changelog

對Linux kernel或LKML來說，git log是十分正式的紀錄。不過還是有些時候，我們只想寫一些對於這個patch的意見、或是給subsystem maintainer的一些參考說明，這些東西就不是那麼適合列入正式的git log中。

一個常見的情況是maintainer對於你的patch會有不同意見，此時可能會有patch v2, v3...的出現，而這些版本之間如果可以有簡單的說明的話，對於patch review會有很大的幫助。

像是這些「非正式性」的log，可以被紀錄在diffstat之後，如：

From 1709e3f1b68a12ce05039a52182288d0f4e21c7a Mon Sep 17 00:00:00 2001
From: Keng-Yu Lin <keng-yu.lin@canonical.com>
Date: Tue, 28 Sep 2010 11:11:57 +0800
Subject: [PATCH v5] dell-laptop: Add debugfs support

Export the status of RF killswitch through debugfs.

The killswitch status is obtained by the SMI to BIOS. Exporting this status
through debugfs can help identify the issue with the misbehaving firmware.

Signed-off-by: Keng-Yu Lin <keng-yu.lin@canonical.com>
---
drivers/platform/x86/dell-laptop.c | 77 ++++++++++++++++++++++++++++++++++++
1 files changed, 77 insertions(+), 0 deletions(-)

V5 fixed operator precedence mess-up of hwswitch_state, and prints the
bit number so that this debug info is complete for hardare manufacturers.

diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
index 4413975..cf8a89a 100644
--- a/drivers/platform/x86/dell-laptop.c
+++ b/drivers/platform/x86/dell-laptop.c
(下略)

Patchwork: https://patchwork.kernel.org/patch/213982/

而在Linux Documentation/SubmittingPatches Section 1.15中也有說明：

Other comments relevant only to the moment or the maintainer, not suitable for the permanent changelog, should also go here. A good example of such comments might be "patch changelogs" which describe what has changed between the v1 and v2 version of the patch.