Linux PCI subsystem development
 help / color / mirror / Atom feed
From: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Subject: [PATCH v2 3/3] pci: update to doc to use 'pci_channel_state_t'
Date: Thu,  2 Jul 2020 18:26:51 +0200	[thread overview]
Message-ID: <20200702162651.49526-4-luc.vanoostenryck@gmail.com> (raw)
In-Reply-To: <20200702162651.49526-1-luc.vanoostenryck@gmail.com>

The type used to describe the PCI channel state is a combination
of a bitwise typedef 'pci_channel_state_t' and an enumeration
of constant __force casted to this typedef: enum pci_channel_state.

It's a bit complex and quite ugly because:
* in C enums are weakly typed (they're essentially the same as 'int')
* sparse only allow to define bitwise ints, not bitwise enums.
But the idea is clearly to enforce typechecking and thus to
use 'pci_channel_state_t' everywhere.

So, update the documentation to use 'pci_chanell_state_t' and hide
'enum pci_channel_state' by showing a simplified but somehow equivalent
definition:
	typedef enum { ... } pci_channel_state_t;
which makes abstraction of the '__bitwise' which would otherwise
just bring unneeded complications here.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
---
 Documentation/PCI/pci-error-recovery.rst | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Documentation/PCI/pci-error-recovery.rst b/Documentation/PCI/pci-error-recovery.rst
index c055deec8c56..ccd713423133 100644
--- a/Documentation/PCI/pci-error-recovery.rst
+++ b/Documentation/PCI/pci-error-recovery.rst
@@ -87,11 +87,11 @@ This structure has the form::
 
 The possible channel states are::
 
-	enum pci_channel_state {
+	typedef enum {
 		pci_channel_io_normal,  /* I/O channel is in normal state */
 		pci_channel_io_frozen,  /* I/O to channel is blocked */
 		pci_channel_io_perm_failure, /* PCI card is dead */
-	};
+	} pci_channel_state_t;
 
 Possible return values are::
 
-- 
2.27.0


  parent reply	other threads:[~2020-07-02 16:28 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-02 16:26 [PATCH v2 0/3] pci: enforce usage of 'pci_channel_state_t' Luc Van Oostenryck
2020-07-02 16:26 ` [PATCH v2 1/3] pci: use 'pci_channel_state_t' instead of 'enum pci_channel_state' Luc Van Oostenryck
2020-07-02 16:26 ` [PATCH v2 2/3] pci: use anonymous 'enum' " Luc Van Oostenryck
2020-07-02 16:26 ` Luc Van Oostenryck [this message]
2020-07-07 22:17 ` [PATCH v2 0/3] pci: enforce usage of 'pci_channel_state_t' Bjorn Helgaas

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200702162651.49526-4-luc.vanoostenryck@gmail.com \
    --to=luc.vanoostenryck@gmail.com \
    --cc=bhelgaas@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox