Fix the "pciehp probing slow" problem reported from Jan C. Nordholz in
http://bugzilla.kernel.org/show_bug.cgi?id=10751.
The command completed bit in Slot Status register applies only to
commands issued to control the attention indicator, power indicator,
power controller, or electromechanical interlock. However, writes to
other parts of the Slot Control register would end up writing to the
control fields. Hence, any write to Slot Control register is
considered as a command. However, if the controller doesn't support
any of attention indicator, power indicator, power controller and
electromechanical interlock, command completed bit would not set in
writing to Slot Control register. In this case, we should not wait for
command completed bit set, otherwise all commands would be considered
not completed in timeout seconds (1 sec.).
The cause of the problem is pciehp driver didn't take this situation
into account. This patch changes pciehp to take it into account. This
patch also add the check for "No Command Completed Support" bit in
Slot Capability register. If it is set, we should not wait for command
completed bit set as well.
This problem seems to be revealed by the commit
c27fb883df that fixed the bug that
pciehp did not wait for command completed properly (pciehp just
ignored the command completion event).
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Current pciehp saves only 8bits of Slot Capability registers in
ctrl->ctrlcap. But it refers more than 8bit for checking EMI capability.
It is clearly a bug and EMI would never work. To fix this problem,
this patch saves full Slot Capability contens in ctrl->slot_cap. It also
reduce the redundant reads of Slot Capability register. And this pach
also cleans up the macros to check the slot capabilitys (e.g. MRL_SENS(),
and so on).
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Current pciehp implementation disables and re-enables hotplug interrupts
in its interrupt handler. This operation might be intend to guarantee
that interrupts for the events newly occured during previous events are
being handled will be successfully generated. But current implementaion
has the following prolems.
- Current interrupt service routin clears status changes without
waiting command completion. Because of this, events might not be
cleared properly.
- Current interrupt service routine clears status changes caused by
disabling or enabling hotplug interrupts itself. This will lose new
events that occurs during previous interrupts are being handled.
- Current implementation doesn't have any serialization mechanism
between the code to wait for command completion and the interrupt
handler that clears the command completion events caused by itself.
There is clearly race conditions between them, and it may cause
the problem that waiting for command completion doesn't work for
example.
To fix those problems, this patch stops disabling/re-enabling hotplug
interrupts in interrupt service routine. Instead of this, this patch
re-inspects Slot Status register after clearing what is presumed to
be the last bending interrupt in order to guarantee that all interrupt
events are serviced.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Earlier patches to split out the hardware init for PCIe hotplug resulted in
some one-time initializations being redone on every resume cycle. Eg.
irq/polling initialization.
This patch splits the hardware init into two parts, and separates the
one-time initializations from those so that they only ever get done once,
as intended.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make use of the previously split out pcie_init_enable_events() function
to reinitialize the hotplug hardware on resume from suspend, but only
when pciehp_force==1. Otherwise behaviour is unmodified.
Signed-off-by: Mark Lord <mlord@pobox.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The slot control register is modified as follows:
(1) Read the register value
(2) Change the value
(3) Write the value to the register
Those must be done atomically, otherwise writing to control register
would cause an unexpected result.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The event handler of PCIEHP driver is unnecessarily very complex. In
addition, current event handler can only a fixed number of events at
the same time, and some of events would be lost if several number of
events happened at the same time.
This patch simplify the event handler using 'work queue', and it also
fix the above-mentioned issue.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes this problem that pciehp driver will sleep
unnecessarily long when waiting for command completion. With this
patch, modprobe pciehp driver becomes very faster as follows for
instance.
o Without this patch
# time /sbin/modprobe pciehp
real 0m4.976s
user 0m0.000s
sys 0m0.004s
o With this patch
# time /sbin/modprobe pciehp
real 0m0.640s
user 0m0.000s
sys 0m0.004s
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The struct php_ctlr seems to be only for complicating codes. This
patch removes struct php_ctlr and related codes.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch cleans up init_slots() in pciehp_core.c based on
pcihp_skeleton.c. This has no functional change.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This makes it possible to build pci hotplug drivers outside of the main
kernel tree, and Sam keeps telling me to move local header files to
their proper places...
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes the problem that system will panic if multiple power
on/off operations are issued to the same slot in parallel. This
problem can be easily reproduced by commands below.
# while true; do echo 1 > power; echo 0 > power; done &
# while true; do echo 1 > power; echo 0 > power; done &
The cause is lack of locking for enable/disable operations. This patch
fixes this problem.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The slot number displayed in info messages would cause a confusion
because those are displayed in several ways (decimal and hex).
Furthermore, those slot number is not same as slot name (directory
name). This patch fixes those improper info messages.
Signed-off-by: Kenji Kaneshige <kaneshige.kenji@jp.fujitsu.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
