It was always abuse to reuse the plugging infrastructure for this,
convert it to the (new) real API for delaying queueing a bit.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Acked-by: David S. Miller <davem@davemloft.net>
This fixes a particular nasty racing problem found when using
Xen hypervisor with the console (hvc) output being routed to the
serial port and the serial port receiving data when
probe_irq_off(probe_irq_on) is running.
Specifically the bug manifests itself with:
[ 4.470693] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[ 4.470693] IP: [<ffffffff810a8c65>] handle_IRQ_event+0xe/0xc9
..snip..
[ 4.470693] Call Trace:
[ 4.470693] <IRQ>
[ 4.470693] [<ffffffff810aa645>] handle_percpu_irq+0x3c/0x69
[ 4.470693] [<ffffffff8123cda7>] __xen_evtchn_do_upcall+0xfd/0x195
[ 4.470693] [<ffffffff810308cf>] ? xen_restore_fl_direct_end+0x0/0x1
[ 4.470693] [<ffffffff8123d873>] xen_evtchn_do_upcall+0x32/0x47
[ 4.470693] [<ffffffff81034dfe>] xen_do_hypervisor_callback+0x1e/0x30
[ 4.470693] <EOI>
[ 4.470693] [<ffffffff8100922a>] ? hypercall_page+0x22a/0x1000
[ 4.470693] [<ffffffff8100922a>] ? hypercall_page+0x22a/0x1000
[ 4.470693] [<ffffffff810301c5>] ? xen_force_evtchn_callback+0xd/0xf
[ 4.470693] [<ffffffff810308e2>] ? check_events+0x12/0x20
[ 4.470693] [<ffffffff81030889>] ? xen_irq_enable_direct_end+0x0/0x7
[ 4.470693] [<ffffffff810ab0a0>] ? probe_irq_on+0x8f/0x1d7
[ 4.470693] [<ffffffff812b105e>] ? serial8250_config_port+0x7b7/0x9e6
[ 4.470693] [<ffffffff812ad66c>] ? uart_add_one_port+0x11b/0x305
The bug is trigged by three actors working together:
A). serial_8250_config_port calling
probe_irq_off(probe_irq_on())
wherein all of the IRQ handlers are being started and shut off.
The functions utilize the sleep functions so the minimum time
they are run is 120 msec.
B). Xen hypervisor receiving on the serial line any character and
setting the bits in the event channel - during this 120 msec timeframe.
C). The hvc API makes a call to 'request_irq' (and hence setting desc->action
to a valid value), much much later - when user space opens
/dev/console (hvc_open). To make the console usable during bootup,
the Xen HVC implementation sets the IRQ chip (and correspondingly
the event channel) much earlier. The IRQ chip handler that is used
is the handle_percpu_irq (aaca49642b)
Back to the issue. When A) is being called it ends up calling the
xen_percpu_chip's chip->startup twice and chip->shutdown once. Those
are set to the default_startup and mask_irq (events.c) respectivly.
If (and this seems to depend on what serial concentrator you use), B)
gets data from the serial port it sets in the event channel a pending bit.
When A) calls chip->startup(), the masking of the pending bit, and
unmasking of the event channel mask, and also setting of the upcall_pending
flag is done (since there is data present on the event channel).
If before the 120 msec has elapsed, any IRQ handler (Xen IRQ has one
IRQ handler, which checks the event channels bitmap to figure which one
to call) is called we end up calling the handle_percpu_irq. The
handle_percpu_irq calls desc->action (which is NULL) and we blow up.
Caveats: I could only reproduce this on 2.6.32 pvops. I am not sure
why this is not showing up on 2.6.38 kernel.
The probe_irq_on/off has code to disable poking specific IRQ lines. This is
done by using the set_irq_noprobe() and then we do not have to
worry about the handle_percpu_irq being called before the IRQ action
handler has been installed.
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The only time when granted pages need to be treated specially is when
using Xen's PTE modification for grant mappings owned by another domain
(that is, only gntdev on PV guests). Otherwise, the area does not
require VM_DONTCOPY and VM_PFNMAP, since it can be accessed just like
any other page of RAM.
Since the vm_operations_struct close operations decrement reference
counts, a corresponding open function that increments them is required
now that it is possible to have multiple references to a single area.
We are careful in the gntdev to check if we can remove those flags. The
reason that we need to be careful in gntdev on PV guests is because we are
not changing the PFN/MFN mapping on PV; instead, we change the application's
page tables to point to the other domain's memory. This means that the vma
cannot be copied without using another grant mapping hypercall; it also
requires special handling on unmap, which is the reason for gntdev's
dependency on the MMU notifier.
For gntalloc, this is not a concern - the pages are owned by the domain
using the gntalloc device, and can be mapped and unmapped in the same manner
as any other page of memory.
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
[v2: Added in git commit "We are.." from email correspondence]
addr is actually a virtual address so use an unsigned long. Fixes:
CC drivers/xen/gntdev.o
drivers/xen/gntdev.c: In function 'map_grant_pages':
drivers/xen/gntdev.c:268: warning: cast from pointer to integer of different size
Reduce the scope of the variable at the same time.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
The caller will not undo a mapping which failed and therefore the
override will not be removed.
This is especially bad in the case of GNTMAP_contains_pte mapping type
mappings where m2p_add_override will destroy the kernel mapping of the
page.
This was observed via a failure of map_grant_pages in gntdev_mmap (due
to userspace using a bad grant reference), which left the page in
question unmapped (because it was a GNTMAP_contains_pte mapping) which
led to a crash later on.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
debug code in TI-ST driver can be enabled by #defining
DEBUG in the first line of the code and in case debugfs
is mounted, the 2 entries in /sys/kernel/debug/ti-st/ will
also provide useful information.
These 2 were broken because of the recent changes to the parsing
logic and the registration mechanism of the protocol drivers,
this patch fixes them.
Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Include the file's .h file and delete the duplicate declarations from
the .c file.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
bIntegratedMMEnabled is always true, so the field and checks can be
eliminated.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The offscreen memory area currently conflicts with the video memory
exported to the framebuffer layer. The driver does not utilize offscreen
memory, so the functionality can be deleted.
The patch also eliminates the one last memory leak when the driver
is unloaded.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The driver does not utilize HW command queue in any way, so the code
can be dropped. The support for the default mode (MMIO) and AGP have
been disabled already anyway.
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This fixes following build error:
In file included from drivers/staging/hv/channel.h:28,
from drivers/staging/hv/vmbus_private.h:30,
from drivers/staging/hv/hv.c:28:
drivers/staging/hv/channel_mgmt.h:234: error: field ‘work’ has incomplete type
Signed-off-by: Mariusz Kozlowski <mk@lab.zgora.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
1, Initialize chip->ms_power_class_en in rtsx_init_options;
2, In reset_ms_pro, set different initial value of change_power_class
according to chip->ms_power_class_en.
Signed-off-by: wwang <wei_wang@realsil.com.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Remove dhd_doflow. iperf result without flow control is unacceptable.
Signed-off-by: Grant Grundler <grundler@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Increase QLEN to avoid TX Queue overflow.
iperf testing results in poor throughput and massive reporting of:
dhd_bus_txdata: out of bus->txq !!!
Also renamed QLEN/et al to reflect usage as TX queue parameters.
Tested with "dhd_doflow = true".
Signed-off-by: Venkat Rao <vrao@broadcom.com>
Signed-off-by: Grant Grundler <grundler@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use kzalloc rather than kmalloc followed by memset with 0.
Found by coccinelle.
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use kzalloc rather than kmalloc followed by memset with 0.
Found by coccinelle.
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use kzalloc rather than kmalloc followed by memset with 0.
Found by coccinelle.
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use kzalloc rather than kmalloc followed by memset with 0.
Found by coccinelle.
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use kzalloc rather than kmalloc followed by memset with 0.
Found by coccinelle.
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fixed all issues reported by checkpatch script on this file.
Signed-off-by: Vinay Sawal <vinaysawal@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The previous implementation flawed, in case some channels are not enabled.
The sorted array would then include channel information of disabled channels,
And misses the enabled ones, when the count is reached.
More troublesome, the loop would not even terminate.
The fix is twofold:
First we skip channels that are not enabled.
Then we use a tested bubble sort algorithm to sort the array.
Since we already allocated exactly the number of bytes we need.
We can exercise bubble sort on the original memory.
In all cases I've seen, the array is already sorted, so this sort
terminates immediately.
Changes since V1:
Fix coding style issues.
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This driver did not conform with the IIO ABI for such devices.
Also the sysfs files that this driver adds were not complete and
partially un-documented.
Update and document ABI
Change License notice, stick to GPL-v2.
Fix indention style
Add option to specify external reference voltage via the regulator framework.
Add mandatory name attribute
Add mandatory out_scale attribute
Changes since V1:
Refine outY_powerdown_mode description
Remove bonus white line
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* the GSM 07.10 specification says in 5.4.3.1 that
'both stations shall set the P bit to 0'
thanks to Alan Cox for finding this explanation in the spec
* without this fix, on Telit & Sim.com modems, opening a new DLC
randomly fails. Not setting PF bit of the control byte gives a
reliable behaviour on these modems.
Signed-off-by: Eric Bénard <eric@eukrea.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Adding support for the OLIMEX ARM-USB-OCD-H JTAG device (id 15ba:002b)
based on FTDI FT2232H
Signed-off-by: JF Argentino <jf.argentino@free.fr>
Acked-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On https://bugs.launchpad.net/ubuntu/+source/linux/+bug/636091, one of
the cases reported is a big timeout on option_send_setup, which causes
some side effects as tty_lock is held. Looks like some of ZTE MF626
devices also don't like the RTS/DTR setting in option_send_setup, like
with 4G XS Stick W14. The reporter confirms which this it solves the
long freezes in his system.
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
