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Date:   Tue, 8 Feb 2022 09:21:06 -0600
From:   Bjorn Helgaas <helgaas@kernel.org>
To:     Li Chen <lchen.firstlove@zohomail.com>
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Kishon Vijay Abraham I <kishon@ti.com>,
        Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>,
        =?utf-8?Q?=22Krzysztof_Wilczy=C5=84ski=22?= <kw@linux.com>,
        Arnd Bergmann <arnd@arndb.de>,
        Bjorn Helgaas <bhelgaas@google.com>,
        linux-pci <linux-pci@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH V6] misc: pci_endpoint_test: simplify endpoint test read
 and write operations
Message-ID: <20220208152106.GA476995@bhelgaas>
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On Mon, Feb 07, 2022 at 11:20:15PM -0500, Li Chen wrote:
>  ---- On Mon, 07 Feb 2022 12:56:13 -0500 Bjorn Helgaas <helgaas@kernel.org> wrote ----
>  > On Mon, Feb 07, 2022 at 04:09:05AM -0500, Li Chen wrote:
>  > > #define to_endpoint_test(priv) container_of((priv), struct pci_endpoint_test, \
>  > > -                     miscdev)
>  > > +                        miscdev)
>  > 
>  > Always indent with tabs when possible:
>  > 
>  >   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/coding-style.rst?id=v5.16#n18
>  > 
>  > Hmm, coding-style.rst is unfortunately not very explicit about that.
>  > 
>  > But it's obvious from the existing code in this file that things
>  > should not be indented four spaces, as you did in
>  > pci_endpoint_test_transfer_data().
> 
> So, can I say space is not allowed in indentation? If so, I should
> not use emacs's tabify, because it will not convert 4 space to
> 8-width tab. I'm also not sure is scripts/Lindent or clang-format is
> a good choice here, they do too much changes.

I don't know how emacs, Lindent, clang-format, etc work.  I *can* tell
you that in Linux code:

  - indents always use tabs (width 8) when possible,

  - up to 7 spaces are allowed after a tab when needed to align
    something with the previous line, and

  - a tab never directly follows a space.

Bjorn