leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
3e9d3d2efc
linux/drivers
History
Philip Oberstaller 3e9d3d2efc usb: gadget: serial: fix re-ordering of tx data 
When a single thread is sending out data over the gadget serial port,
gs_start_tx() will be called both from the sender context and from the
write completion. Since the port lock is released before the packet is
queued, the order in which the URBs are submitted is not guaranteed.
E.g.

  sending thread                      completion (interrupt)

  gs_write()
    LOCK
                                      gs_write_complete()
                                        LOCK (wait)
    gs_start_tx()
      req1 = list_entry(pool->next)
      UNLOCK
                                        LOCK (acquired)
                                        gs_start_tx()
                                          req2 = list_entry(pool->next)
                                          UNLOCK
                                          usb_ep_queue(req2)
      usb_ep_queue(req1)

I.e., req2 is submitted before req1 but it contains the data that
comes after req1.

To reproduce, use SMP with sending thread and completion pinned to
different CPUs, or use PREEMPT_RT, and add the following delay just
before the call to usb_ep_queue():

		if (port->write_started > 0 && !list_empty(pool))
			udelay(1000);

To work around this problem, make sure that only one thread is running
through the gs_start_tx() loop with an extra flag write_busy. Since
gs_start_tx() is always called with the port lock held, no further
synchronisation is needed. The original caller will continue through
the loop when the request was successfully submitted.

Signed-off-by: Philip Oberstaller <Philip.Oberstaller@septentrio.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2015-04-27 14:44:29 -05:00
..
accessibility
acpi More power management and ACPI updates for v4.1-rc1 2015-04-26 13:56:35 -07:00
amba
android
ata powerpc updates for 4.1 2015-04-16 13:53:32 -05:00
atm
auxdisplay
base Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
bcma Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2015-04-17 15:50:54 -04:00
block Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
bluetooth Bluetooth: btusb: Use proper data structures for Intel vendor events 2015-04-09 10:42:18 +03:00
bus ARM: SoC driver updates for v4.1 2015-04-22 09:18:17 -07:00
cdrom
char Char/Misc driver patches for 4.1-rc1 2015-04-21 09:42:58 -07:00
clk ARM: SoC multiplatform code changes for v4.1 2015-04-22 09:20:15 -07:00
clocksource Initial ACPI support for arm64: 2015-04-24 08:23:45 -07:00
connector
cpufreq cpufreq: intel_pstate: Fix an annoying !CONFIG_SMP warning 2015-04-15 23:02:24 +02:00
cpuidle ARM: SoC fixes for v4.1 2015-04-22 09:03:30 -07:00
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2015-04-26 13:51:05 -07:00
dca
devfreq
dio
dma Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2015-04-24 09:49:37 -07:00
dma-buf dma-buf: cleanup dma_buf_export() to make it easily extensible 2015-04-21 14:47:16 +05:30
edac
eisa
extcon Char/Misc driver patches for 4.1-rc1 2015-04-21 09:42:58 -07:00
firewire
firmware ARM: SoC driver updates for v4.1 2015-04-22 09:18:17 -07:00
fmc
gpio ARM: SoC cleanups for v4.1 2015-04-22 09:04:39 -07:00
gpu Merge tag 'drm-intel-next-fixes-2015-04-25' of git://anongit.freedesktop.org/drm-intel into drm-fixes 2015-04-27 10:35:15 +10:00
hid Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2015-04-14 18:25:15 -07:00
hsi
hv
hwmon hwmon: (w83795) use find_closest_descending() in pwm_freq_to_reg() 2015-04-17 09:03:55 -04:00
hwspinlock
hwtracing/coresight Char/Misc driver patches for 4.1-rc1 2015-04-21 09:42:58 -07:00
i2c Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2015-04-26 17:44:09 -07:00
ide ide: remove deprecated use of pci api 2015-04-17 15:32:07 -04:00
idle Power management and ACPI updates for v4.1-rc1 2015-04-14 20:21:54 -07:00
iio Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial 2015-04-14 09:50:27 -07:00
infiniband Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
input platform/chrome: Updates for v4.1 2015-04-26 13:36:02 -07:00
iommu Merge git://git.infradead.org/intel-iommu 2015-04-26 17:47:46 -07:00
ipack
irqchip Initial ACPI support for arm64: 2015-04-24 08:23:45 -07:00
isdn Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-04-15 09:00:47 -07:00
leds This is the bulk of GPIO changes for the v4.1 development 2015-04-18 08:22:10 -04:00
lguest Some virtio internal cleanups, a new virtio device "virtio input", and 2015-04-22 10:55:06 -07:00
macintosh
mailbox
mcb
md md updates for 4.1 2015-04-24 09:28:01 -07:00
media v4l: xilinx: fix for include file movement 2015-04-26 09:56:08 -07:00
memory ARM: SoC driver updates for v4.1 2015-04-22 09:18:17 -07:00
memstick memstick: mspro_block: add missing curly braces 2015-04-17 09:04:09 -04:00
message
mfd platform/chrome: Updates for v4.1 2015-04-26 13:36:02 -07:00
misc Char/Misc driver patches for 4.1-rc1 2015-04-21 09:42:58 -07:00
mmc Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2015-04-24 09:49:37 -07:00
mtd Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
net Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
nfc
ntb
nubus
of Devicetree updates for 4.1: 2015-04-24 08:46:18 -07:00
oprofile Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
parisc parisc: Eliminate sg_virt_addr() and private scatterlist.h 2015-04-21 22:02:43 +02:00
parport
pci xen: features and fixes for 4.1-rc0 2015-04-16 14:01:03 -05:00
pcmcia ARM: SoC cleanups for v4.1 2015-04-22 09:04:39 -07:00
phy USB patches for 4.1-rc1 2015-04-13 17:07:21 -07:00
pinctrl pinctrl: fix allmodconfig noise 2015-04-15 10:02:42 +02:00
platform platform-drivers-x86 for 4.1 2015-04-26 13:44:46 -07:00
pnp Power management and ACPI updates for v4.1-rc1 2015-04-14 20:21:54 -07:00
power
powercap powercap / RAPL: Add support for Intel Skylake processors 2015-04-15 23:06:16 +02:00
pps
ps3
ptp
pwm pwm: Remove __init initializer for pwm_add_table() 2015-04-23 14:50:52 +02:00
rapidio
ras
regulator == Changes to existing drivers == 2015-04-14 17:29:55 -07:00
remoteproc
reset
rpmsg
rtc drivers/rtc/rtc-at91rm9200.c: make IO endian agnostic 2015-04-17 09:04:12 -04:00
s390 Some virtio internal cleanups, a new virtio device "virtio input", and 2015-04-22 10:55:06 -07:00
sbus drivers/sbus/char/envctrl.c: ignore orderly_poweroff return value 2015-04-15 16:35:23 -07:00
scsi Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2015-04-24 10:22:09 -07:00
sfi
sh
sn
soc - fix unused variable warning for pmic-wrapper 2015-04-14 00:43:28 +02:00
spi Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2015-04-24 09:49:37 -07:00
spmi
ssb Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2015-04-17 15:50:54 -04:00
staging Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2015-04-24 10:22:09 -07:00
tc
thermal
thunderbolt
tty Devicetree updates for 4.1: 2015-04-24 08:46:18 -07:00
uio
usb usb: gadget: serial: fix re-ordering of tx data 2015-04-27 14:44:29 -05:00
uwb
vfio
vhost Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2015-04-24 10:22:09 -07:00
video fbdev changes for v4.1 2015-04-20 15:16:25 -07:00
virt
virtio virtio: drop virtio_device_is_legacy_only 2015-04-15 12:41:14 +09:30
vlynq
vme
w1
watchdog Merge git://www.linux-watchdog.org/linux-watchdog 2015-04-22 11:22:55 -07:00
xen Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2015-04-24 10:22:09 -07:00
zorro
Kconfig
Makefile