A published errata for ppc440epx states, that when running Linux with
both EHCI and OHCI modules loaded, the EHCI module experiences a fatal
error when a high-speed device is connected to the USB2.0, and
functions normally if OHCI module is not loaded.
There used to be recommendation to use only hi-speed or full-speed
devices with specific conditions, when respective module was unloaded.
Later, it was observed that ohci suspend is enough to keep things
going, and it was turned into workaround, as explained below.
Quote from original descriprion:
The 440EPx USB 2.0 Host controller is an EHCI compliant controller. In
USB 2.0 Host controllers, each EHCI controller has one or more companion
controllers, which may be OHCI or UHCI. An USB 2.0 Host controller will
contain one or more ports. For each port, only one of the controllers
is connected at any one time. In the 440EPx, there is only one OHCI
companion controller, and only one USB 2.0 Host port.
All ports on an USB 2.0 controller default to the companion
controller. If you load only an ohci driver, it will have control of
the ports and any deviceplugged in will operate, although high speed
devices will be forced to operate at full speed. When an ehci driver
is loaded, it explicitly takes control of the ports. If there is a
device connected, and / or every time there is a new device connected,
the ehci driver determines if the device is high speed or not. If it
is high speed, the driver retains control of the port. If it is not,
the driver explicitly gives the companion controller control of the
port.
The is a software workaround that uses
Initial version of the software workaround was posted to
linux-usb-devel:
http://www.mail-archive.com/linux-usb-devel@lists.sourceforge.net/msg54019.html
and later available from amcc.com:
http://www.amcc.com/Embedded/Downloads/download.html?cat=1&family=15&ins=2
The patch below is generally based on the latter, but reworked to
powerpc/of_device USB drivers, and uses a few devicetree inquiries to
get rid of (some) hardcoded defines.
Signed-off-by: Vitaly Bordug <vitb@kernel.crashing.org>
Signed-off-by: Stefan Roese <sr@denx.de>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1069c) changes the way OHCI root-hub status-change
interrupts are enabled. Currently a special HCD method,
hub_irq_enable(), is called when the hub driver is finished using a
root hub. This approach turns out to be subject to races, resulting
in unnecessary polling.
The patch does away with the method entirely. Instead, the driver
automatically enables the RHSC interrupt when no more status changes
are present. This scheme is safe with controllers using
level-triggered semantics for their interrupt flags.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This reverts commit e872154921.
Andrey Borzenkov reports that it resulted in a totally hung machine for
him when loading the OHCI driver. Extensive netconsole capture with
SysRq output shows that modprobe gets stuck in ohci_hub_status_data()
when probing and enabling the OHCI controller, see for example
http://lkml.org/lkml/2008/7/5/236
for an analysis.
The problem appears to be an interrupt flood triggered by the commit
that gets reverted, and Andrey confirmed that the revert makes things
work for him again.
Reported-and-tested-by: Andrey Borzenkov <arvidjaar@mail.ru>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <david-b@pacbell.net>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch (as1069b) changes the way OHCI root-hub status-change
interrupts are enabled. Currently a special HCD method,
hub_irq_enable(), is called when the hub driver is finished using a
root hub. This approach turns out to be subject to races, resulting
in unnecessary polling.
The patch does away with the method entirely. Instead, the driver
automatically enables the RHSC interrupt when no more status changes
are present. This scheme is safe with controllers using
level-triggered semantics for their interrupt flags.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Update MPC5200 drivers to also look for compatible properties in the
form "fsl,mpc5200-*" to better conform to open firmware generic names
recommended practice as published here:
http://www.openfirmware.org/1275/practice/gnames/gnamv14a.html
This patch should *not* break compatibility with older device trees
which do not use the 'fsl,' prefix. The drivers will still bind against
the older names also.
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Host controller IRQs are supposed to be serviced with interrupts
disabled. This patch (as1026) adds an IRQF_DISABLED flag to all the
controller drivers that lack it. It also replaces the
spin_lock_irqsave() and spin_unlock_irqrestore() calls in uhci_irq()
with simple spin_lock() and spin_unlock().
This fixes Bugzilla #9335.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Add OHCI big endian frame_no quirk. The frame_no value stored in the
HCCA is a 16 bit field at a specific offset, but since not all CPUs can
do 16-bit memory accesses it's used as a 32 bit field. And that's why
big-endian OHCI must shift 16 bits ... unless the spec is not followed.
Currently there's one MPC52xx platform that doesn't need the shift. This
patch adds a new "big endian frame_no" quirk to control that at runtime.
Signed-off-by: Valentine Barshak <vbarshak@ru.mvista.com>
Acked-by: Dale Farnsworth <dale@farnsworth.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
for consistency with other Open Firmware interfaces (and Sparc).
This is just a straight replacement.
This leaves the compatibility define in place.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
PPC embedded systems can have a ohci controller builtin. In the
new model, it will end up as a driver on the of_platform bus,
this patches takes care of them.
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
