[PATCH v5 13/13] PCI Hotplug: schedule fakephp for feature removal

From: Alex Chiang <achiang@hp.com>
To: jbarnes@virtuousgeek.org
Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
	Alex Chiang <achiang@hp.com>
Subject: [PATCH v5 13/13] PCI Hotplug: schedule fakephp for feature removal
Date: Fri, 20 Mar 2009 14:56:56 -0600	[thread overview]
Message-ID: <20090320205656.12275.64680.stgit@bob.kio> (raw)
In-Reply-To: <20090320204327.12275.43010.stgit@bob.kio>

Now that the PCI core is capable of function-level remove and rescan
as well as bus-level rescan, there's no functional need to keep fakephp
anymore.

We keep it around for userspace compatibility reasons, schedule removal
in three years.

Signed-off-by: Alex Chiang <achiang@hp.com>
---

 Documentation/feature-removal-schedule.txt |   33 ++++++++++++++++++++++++++++
 1 files changed, 33 insertions(+), 0 deletions(-)

diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt
index 20d3b94..8851eea 100644
--- a/Documentation/feature-removal-schedule.txt
+++ b/Documentation/feature-removal-schedule.txt
@@ -335,6 +335,7 @@ Why:	In 2.6.18 the Secmark concept was introduced to replace the "compat_net"
 	Secmark, it is time to deprecate the older mechanism and start the
 	process of removing the old code.
 Who:	Paul Moore <paul.moore@hp.com>
+
 ---------------------------
 
 What:	sysfs ui for changing p4-clockmod parameters
@@ -344,3 +345,35 @@ Why:	See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and
 	Removal is subject to fixing any remaining bugs in ACPI which may
 	cause the thermal throttling not to happen at the right time.
 Who:	Dave Jones <davej@redhat.com>, Matthew Garrett <mjg@redhat.com>
+
+---------------------------
+
+What:	fakephp and associated sysfs files in /sys/bus/pci/slots/
+When:	2011
+Why:	In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
+	represent a machine's physical PCI slots. The change in semantics
+	had userspace implications, as the hotplug core no longer allowed
+	drivers to create multiple sysfs files per physical slot (required
+	for multi-function devices, e.g.). fakephp was seen as a developer's
+	tool only, and its interface changed. Too late, we learned that
+	there were some users of the fakephp interface.
+
+	In 2.6.30, the original fakephp interface was restored. At the same
+	time, the PCI core gained the ability that fakephp provided, namely
+	function-level hot-remove and hot-add.
+
+	Since the PCI core now provides the same functionality, exposed in:
+
+		/sys/bus/pci/rescan
+		/sys/bus/pci/devices/.../remove
+		/sys/bus/pci/devices/.../rescan
+
+	there is no functional reason to maintain fakephp as well.
+
+	We will keep the existing module so that 'modprobe fakephp' will
+	present the old /sys/bus/pci/slots/... interface for compatibility,
+	but users are urged to migrate their applications to the API above.
+
+	After a reasonable transition period, we will remove the legacy
+	fakephp interface.
+Who:	Alex Chiang <achiang@hp.com>

