From: "Zoltán Böszörményi" <zboszor@pr.hu>
To: linux-usb@vger.kernel.org, linux-watchdog@vger.kernel.org,
linux-i2c@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, "Zoltán Böszörményi" <zboszor@pr.hu>
Subject: [PATCH 0/3] Fix sp5100_tco watchdog driver regression
Date: Sat, 1 Apr 2017 12:06:06 +0200 [thread overview]
Message-ID: <20170401100609.9054-1-zboszor@pr.hu> (raw)
Three drivers are accessing the same I/O ports (0xcd6 / 0xcd7) on
AMD SB800 based machines without synchronization or with excluding
each other out:
* the USB quirk for isochronous transfers on SB800 (no locking)
* sp5100_tco (request_region)
* i2c-piix4 (request_region)
Historically, the sp5100_tco watchdog driver used request_region()
for these I/O ports but an i2c-piix4 improvement for SB800 in
Linux 4.4-rc4 also added a request_region() call. Because of this
and the load order of these drivers, this caused a regression and
the watchdog function became non-functional. The commit that caused
the regression is:
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
I was informed by Guenter Roeck <linux@roeck-us.net> that the
alternative, i.e. using request_muxed_region() can fail, either
because of a resource allocation failure, which is quite possible
with long uptimes, or because there are no guarantees that an as yet
unknown driver would also use request_muxed_region() consistently.
Because of this, a common mutex across these driver was chosen to
synchronize I/O port accesses and request_region() calls are removed
from both i2c-piix4 and sp5100_tco to make the code uniform.
This patch series implements this and restores the watchdog function.
Signed-off-by: Zoltán Böszörményi <zboszor@pr.hu>
drivers/i2c/busses/i2c-piix4.c | 59 ++++++++++++--------------------------
drivers/usb/host/pci-quirks.c | 14 ++++++---
drivers/watchdog/sp5100_tco.c | 24 +++++++---------
drivers/watchdog/sp5100_tco.h | 10 ++++---
include/linux/sb800.h | 15 ++++++++++
5 files changed, 61 insertions(+), 61 deletions(-)
next reply other threads:[~2017-04-01 10:07 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-04-01 10:06 Zoltán Böszörményi [this message]
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
[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 ` [PATCH 0/5 v3] Fix sp5100_tco watchdog driver regression Zoltán Böszörményi
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
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