From: "Zoltán Böszörményi" <zboszor@pr.hu>
To: linux-kernel@vger.kernel.org
Cc: linux-usb@vger.kernel.org, linux-watchdog@vger.kernel.org,
linux-i2c@vger.kernel.org,
"Paul Menzel" <paulepanter@users.sourceforge.net>,
"Christian Fetzer" <fetzer.ch@gmail.com>,
"Jean Delvare" <jdelvare@suse.com>,
"Nehal Shah" <nehal-bakulchandra.shah@amd.com>,
"Tim Small" <tim@seoss.co.uk>,
"Guenter Roeck" <linux@roeck-us.net>,
kernel@ekass.net, wim@iguana.be, jlayton@poochiereds.net,
marc.2377@gmail.com, cshorler@googlemail.com, wsa@the-dreams.de,
regressions@leemhuis.info, "Zoltán Böszörményi" <zboszor@pr.hu>
Subject: [PATCH 0/5 v3] Fix sp5100_tco watchdog driver regression
Date: Wed, 21 Jun 2017 05:53:44 +0200 [thread overview]
Message-ID: <20170621035349.4125-1-zboszor@pr.hu> (raw)
In-Reply-To: <20170403075133.12343-1-zboszor@pr.hu>
This patch series fixes a regression introduced by:
commit 2fee61d22e606fc99ade9079fda15fdee83ec33e
Author: Christian Fetzer <fetzer.ch@gmail.com>
Date: Thu Nov 19 20:13:48 2015 +0100
i2c: piix4: Add support for multiplexed main adapter in SB800
The regression caused sp5100_tco fail to load:
piix4_smbus 0000:00:14.0: SMBus Host Controller at 0xb00, revision 0
piix4_smbus 0000:00:14.0: Using register 0x2c for SMBus port selection
piix4_smbus 0000:00:14.0: Auxiliary SMBus Host Controller at 0xb20
sp5100_tco: SP5100/SB800 TCO WatchDog Timer Driver v0.05
sp5100_tco: PCI Vendor ID: 0x1002, Device ID: 0x4385, Revision ID: 0x42
sp5100_tco: I/O address 0x0cd6 already in use
Notable bugzilla links about this issue:
https://bugzilla.kernel.org/show_bug.cgi?id=170741
https://bugzilla.redhat.com/show_bug.cgi?id=1369269
https://bugzilla.redhat.com/show_bug.cgi?id=1406844
The previous two versions of this patch series introduced
a common mutex to synchronize access to the I/O port pair
0xcd6 / 0xcd7 used by the AMD SB800 USB PCI quirk code and
the i2c-piix and sp5100_tco drivers. The common mutex was
criticized because it introduces an inter-dependency between
drivers.
This approach modifies the request_muxed_region() semantics and
modifies the possible use cases.
The first patch in the series adds a new IORESOURCE_ALLOCATED
flag that alloc_resource() sets and free_resource() considers.
The core of __request_region() is factored out into a new function
that doesn't allocate. With this change, drivers can use the
pre-existing DEFINE_RES_IO_NAMED() static initialized macro
to declare struct resource statically (e.g. on the stack)
and pass the address of it to the new __request_declared_region()
function. A new macro called request_declared_muxed_region()
was added to exploit this functionality. Because of the new
IORESOURCE_ALLOCATED resource flag, release_region() can still
be called with the old interface (the port region start and
end values) and it won't attempt to free a non-allocated resource.
This eliminated one failure case that can come from allocation
errors.
The second patch modifies the behaviour of IORESOURCE_MUXED,
a.k.a. the request_*muxed_region() macros. When these macros
are called, the caller goes to sleep when there is any conflicting
regions, even if the conflicting region did not use the
IORESOURCE_MUXED flag. The kernel logs this inconsistent
flag usage with KERN_ERR. This change eliminates the second
failure case for IORESOURCE_MUXED and request_muxed_region()
can be used like mutex_lock(), i.e. it returns only in case it
could successfully request the region.
The last three patches adds proper synchronization to
the USB PCI quirks code and the i2c-piix and sp5100_tco drivers.
The result is that the sp5100_tco driver can load and works again:
piix4_smbus 0000:00:14.0: SMBus Host Controller at 0xb00, revision 0
piix4_smbus 0000:00:14.0: Using register 0x2c for SMBus port selection
piix4_smbus 0000:00:14.0: Auxiliary SMBus Host Controller at 0xb20
sp5100_tco: SP5100/SB800 TCO WatchDog Timer Driver v0.05
sp5100_tco: PCI Vendor ID: 0x1002, Device ID: 0x4385, Revision ID: 0x42
sp5100_tco: Using 0xfed80b00 for watchdog MMIO address
sp5100_tco: Last reboot was not triggered by watchdog.
sp5100_tco: initialized (0xffffba2f4192db00). heartbeat=60 sec (nowayout=0)
Signed-off-by: Zoltán Böszörményi <zboszor@pr.hu>
---
drivers/i2c/busses/i2c-piix4.c | 42 ++++++++++--------------------
drivers/usb/host/pci-quirks.c | 3 +++
drivers/watchdog/sp5100_tco.c | 25 +++++++++---------
include/linux/ioport.h | 5 ++++
kernel/resource.c | 59 ++++++++++++++++++++++++++++++------------
5 files changed, 75 insertions(+), 59 deletions(-)
next prev parent reply other threads:[~2017-06-21 4:04 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <<20170401110223.12056-1-zboszor@pr.hu>
2017-04-03 7:51 ` [PATCH 0/3 v2] Fix regression in the sp5100_tco driver Zoltan Boszormenyi
2017-04-03 7:51 ` [PATCH 1/3 v2] usb: pci-quirks: Add a common mutex for the I/O port pair of SB800 Zoltan Boszormenyi
2017-06-20 14:12 ` [1/3, " Guenter Roeck
2017-04-03 7:51 ` [PATCH 2/3 v2] i2c: i2c-piix4: Use the common mutex Zoltan Boszormenyi
2017-04-19 18:43 ` Wolfram Sang
2017-04-03 7:51 ` [PATCH 3/3 v2] watchdog: sp5100_tco: " Zoltan Boszormenyi
2017-06-21 3:53 ` Zoltán Böszörményi [this message]
2017-06-21 3:53 ` [PATCH 1/5] Extend the request_region() infrastructure Zoltán Böszörményi
2017-06-21 3:53 ` [PATCH 2/5] Modify behaviour of request_*muxed_region() Zoltán Böszörményi
2017-06-21 3:53 ` [PATCH 3/5] usb: pci-quirks: Protect the I/O port pair of SB800 Zoltán Böszörményi
2017-06-21 3:53 ` [PATCH 4/5] i2c: i2c-piix4: Use request_declared_muxed_region() Zoltán Böszörményi
2017-06-21 3:53 ` [PATCH 5/5] watchdog: sp5100_tco: " Zoltán Böszörményi
2017-06-21 15:09 ` Guenter Roeck
2017-06-22 13:21 ` [PATCH 0/5 v4] Fix sp5100_tco watchdog driver regression Zoltán Böszörményi
2017-06-22 13:21 ` [PATCH 1/5 v2] Extend the request_region() infrastructure Zoltán Böszörményi
2017-07-14 8:33 ` Boszormenyi Zoltan
2017-06-22 13:21 ` [PATCH 2/5 v2] Modify behaviour of request_*muxed_region() Zoltán Böszörményi
2017-07-08 15:37 ` [2/5,v2] " Guenter Roeck
2017-06-22 13:21 ` [PATCH 3/5 v4] usb: pci-quirks: Protect the I/O port pair of SB800 Zoltán Böszörményi
2017-07-14 8:34 ` Boszormenyi Zoltan
2017-07-14 11:36 ` Greg Kroah-Hartman
2017-06-22 13:21 ` [PATCH 4/5 v4] i2c: i2c-piix4: Use request_declared_muxed_region() Zoltán Böszörményi
2017-06-22 13:21 ` [PATCH 5/5 v4] watchdog: sp5100_tco: " Zoltán Böszörményi
2017-07-14 8:34 ` Boszormenyi Zoltan
2017-07-06 7:50 ` [PATCH 0/5 v4] Fix sp5100_tco watchdog driver regression Boszormenyi Zoltan
[not found] ` <CAETC-g-0ZYiD=j_sAtYpfr0t-rciiTx3ruvpGuwEud+nbbpiBg@mail.gmail.com>
[not found] ` <CAETC-g_YF7TWv+LNrNQrX9AY_-iepCeE0EmCKWYF4VyQzRY+UQ@mail.gmail.com>
2017-07-07 2:26 ` Marcelo "Marc" Ranolfi
2017-04-01 10:06 [PATCH 0/3] " Zoltán Böszörményi
2017-04-01 10:06 ` [PATCH 1/3] usb: pci-quirks: Add a header for SB800 I/O ports and mutex for locking Zoltán Böszörményi
2017-04-01 10:06 ` [PATCH 3/3] watchdog: sp5100_tco: Synchronize I/O port accesses Zoltán Böszörményi
2017-04-01 11:02 ` [PATCH 0/3, resend] Fix sp5100_tco watchdog driver regression Zoltan Boszormenyi
2017-04-01 11:02 ` [PATCH 1/3] usb: pci-quirks: Add a header for SB800 I/O ports and mutex for locking Zoltan Boszormenyi
2017-04-01 13:59 ` Greg KH
2017-04-01 14:40 ` Alan Stern
2017-04-01 15:09 ` Boszormenyi Zoltan
2017-04-01 15:07 ` Boszormenyi Zoltan
2017-04-01 11:02 ` [PATCH 3/3] watchdog: sp5100_tco: Synchronize I/O port accesses Zoltan Boszormenyi
2017-04-01 11:08 ` [PATCH 2/3] i2c: i2c-piix4: Synchronize I/O port accesses with the SB800 USB quirk Zoltan Boszormenyi
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