Resolves kernel.org bug 14914.
Remove entry for 2770:915d (usb digital camera with mass storage
support) from unusual_devs.h. The fix triggered by the entry causes
the file system on the camera to be completely inaccessible (no
partition table, the device is not mountable).
The patch works, but let me clarify a few things about it. All the
patch does is remove the entry for this device from the
drivers/usb/storage/unusual_devs.h, which is supposed to help with a
problem with the device's reported size (I think). I'm pretty sure it
was originally added for a reason, so I'm not sure removing it won't
cause other problems to reappear. Also, I should note that this
unusual_devs.h entry was present (and activating workarounds) in
2.6.29, but in that version everything works fine. Starting with
2.6.30, things no longer work.
Signed-off-by: Ryan May <rmay31@gmail.com>
Cc: Rohan Hart <rohan.hart17@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This error message is not actually an error, it's an information
message. It is triggered when a transfer which ended in a NAQ is
retried successfully by the hardware.
Signed-off-by: Colin Tuckley <colin.tuckley@arm.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Borislav Petkov reports issues with duplicate sysfs endpoint files after a
resume from a hibernate. It turns out that the code to support alternate
settings under xHCI has issues when a device with a non-default alternate
setting is reset during the hibernate:
[ 427.681810] Restarting tasks ...
[ 427.681995] hub 1-0:1.0: state 7 ports 6 chg 0004 evt 0000
[ 427.682019] usb usb3: usb resume
[ 427.682030] ohci_hcd 0000:00:12.0: wakeup root hub
[ 427.682191] hub 1-0:1.0: port 2, status 0501, change 0000, 480 Mb/s
[ 427.682205] usb 1-2: usb wakeup-resume
[ 427.682226] usb 1-2: finish reset-resume
[ 427.682886] done.
[ 427.734658] ehci_hcd 0000:00:12.2: port 2 high speed
[ 427.734663] ehci_hcd 0000:00:12.2: GetStatus port 2 status 001005 POWER sig=se0 PE CONNECT
[ 427.746682] hub 3-0:1.0: hub_reset_resume
[ 427.746693] hub 3-0:1.0: trying to enable port power on non-switchable hub
[ 427.786715] usb 1-2: reset high speed USB device using ehci_hcd and address 2
[ 427.839653] ehci_hcd 0000:00:12.2: port 2 high speed
[ 427.839666] ehci_hcd 0000:00:12.2: GetStatus port 2 status 001005 POWER sig=se0 PE CONNECT
[ 427.847717] ohci_hcd 0000:00:12.0: GetStatus roothub.portstatus [1] = 0x00010100 CSC PPS
[ 427.915497] hub 1-2:1.0: remove_intf_ep_devs: if: ffff88022f9e8800 ->ep_devs_created: 1
[ 427.915774] hub 1-2:1.0: remove_intf_ep_devs: bNumEndpoints: 1
[ 427.915934] hub 1-2:1.0: if: ffff88022f9e8800: endpoint devs removed.
[ 427.916158] hub 1-2:1.0: create_intf_ep_devs: if: ffff88022f9e8800 ->ep_devs_created: 0, ->unregistering: 0
[ 427.916434] hub 1-2:1.0: create_intf_ep_devs: bNumEndpoints: 1
[ 427.916609] ep_81: create, parent hub
[ 427.916632] ------------[ cut here ]------------
[ 427.916644] WARNING: at fs/sysfs/dir.c:477 sysfs_add_one+0x82/0x96()
[ 427.916649] Hardware name: System Product Name
[ 427.916653] sysfs: cannot create duplicate filename '/devices/pci0000:00/0000:00:12.2/usb1/1-2/1-2:1.0/ep_81'
[ 427.916658] Modules linked in: binfmt_misc kvm_amd kvm powernow_k8 cpufreq_ondemand cpufreq_powersave cpufreq_userspace freq_table cpufreq_conservative ipv6 vfat fat
+8250_pnp 8250 pcspkr ohci_hcd serial_core k10temp edac_core
[ 427.916694] Pid: 278, comm: khubd Not tainted 2.6.33-rc2-00187-g08d869a-dirty #13
[ 427.916699] Call Trace:
The problem is caused by a mismatch between the USB core's view of the
device state and the USB device and xHCI host's view of the device state.
After the device reset and re-configuration, the device and the xHCI host
think they are using alternate setting 0 of all interfaces. However, the
USB core keeps track of the old state, which may include non-zero
alternate settings. It uses intf->cur_altsetting to keep the endpoint
sysfs files for the old state across the reset.
The bandwidth allocation functions need to know what the xHCI host thinks
the current alternate settings are, so original patch set
intf->cur_altsetting to the alternate setting 0. This caused duplicate
endpoint files to be created.
The solution is to not set intf->cur_altsetting before calling
usb_set_interface() in usb_reset_and_verify_device(). Instead, we add a
new flag to struct usb_interface to tell usb_hcd_alloc_bandwidth() to use
alternate setting 0 as the currently installed alternate setting.
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Borislav Petkov <petkovbb@googlemail.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
These controllers say "unknown" for their speed in sysfs, which
obviously isn't correct.
Reported-by: Kurt Garloff <garloff@novell.com>
Cc: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Cc: David Vrabel <david.vrabel@csr.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1330) fixes a bug in khbud's handling of remote
wakeups. When a device sends a remote-wakeup request, the parent hub
(or the host controller driver, for directly attached devices) begins
the resume sequence and notifies khubd when the sequence finishes. At
this point the port's SUSPEND feature is automatically turned off.
However the device needs an additional 10-ms resume-recovery time
(TRSMRCY in the USB spec). Khubd does not wait for this delay if the
SUSPEND feature is off, and as a result some devices fail to behave
properly following a remote wakeup. This patch adds the missing
delay to the remote-wakeup path.
It also extends the resume-signalling delay used by ehci-hcd and
uhci-hcd from 20 ms (the value in the spec) to 25 ms (the value we use
for non-remote-wakeup resumes). The extra time appears to help some
devices.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Cc: Rickard Bellini <rickard.bellini@ericsson.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1321) fixes a problem with EHCI and UHCI root-hub
suspends: If the suspend occurs while a port is trying to resume, the
resume doesn't finish and simply gets lost. When remote wakeup is
enabled, this is undesirable behavior.
The patch checks first to see if any port resumes are in progress, and
if they are then it fails the root-hub suspend with -EBUSY.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1320) fixes two problems related to interrupt-URB
scheduling in ehci-hcd.
URBs with an interval of 2 or 4 microframes aren't handled.
For the time being, the patch reduces to interval to 1 uframe.
URBs are constrained to have an interval no larger than 1024
frames by usb_submit_urb(). But some EHCI controllers allow
use of a schedule as short as 256 frames; for these
controllers we may have to decrease the interval to the
actual schedule length.
The second problem isn't very significant since few devices expose
interrupt endpoints with an interval larger than 256 frames. But the
first problem is critical; it will prevent the kernel from working
with devices having interrupt intervals of 2 or 4 uframes.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Tested-by: Glynn Farrow <farrowg@sg.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Memory allocations with GFP_KERNEL can cause IO to a storage
device which can fail resulting in a need to reset the device.
Therefore GFP_KERNEL cannot be safely used between usb_lock_device()
and usb_unlock_device(). Replace by GFP_NOIO.
Signed-off-by: Oliver Neukum <oliver@neukum.org>
Cc: stable <stable@kernel.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch adds a mask bit which was mistakenly omitted from the
as1311 patch (usb-storage: add BAD_SENSE flag).
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix a regression introduced by commit
715b1dc01f ("USB: usb_debug,
usb_generic_serial: implement multi urb write").
URB transfer buffer was never freed when using multi-urb writes.
Currently the only driver enabling multi-urb writes is usb_debug.
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Cc: Greg KH <greg@kroah.com>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fix a possible race bug in drivers/usb/serial/generic with
the new kfifo API.
Please apply it to the 2.6.33-rc* tree.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
brightness status is reported by the Apple Cinema Displays as an
'unsigned char' (u8) value, but the code used 'char' instead.
Note that he driver was developed on the PowerPC architecture,
where the two types are synonymous, which is not always the case.
Fixed that. Otherwise the driver will interpret brightness
levels > 127 as negative, and fail to load.
Signed-off-by: pancho horrillo <pancho@pancho.name>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The wTotalLength should contain the sum of the interface and unit
descriptor sizes per the Audio Device Class specification 1.0.
Reported-by: Sergey Lapin <slapin@ossfans.org>
Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
commit 91c8a5a998 broke
compilation of this driver after it introduced
otg_init() as a static inline in <linux/usb/otg.h>
Reported-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Some of these workarounds are already in place, but labeled as affecting
all BF52x parts. Since we have official anomaly numbers now, use those
defines. And since writing to the FIFO has a similar hang issue as reading
from the FIFO, implement the workaround there too when necessary.
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes the below array index out of bounds issue.
Buffer overflow, array index of 'aInfo' may be out of
bounds. Array 'aInfo' of size 78 may use index value(s) 6..84
The data stored in 'aInfo' array exceeds the array size of 78.
This patch increases the size of this array to hold the string
correctly without any memory corruption.
This issue was reported by Klockwork tool.
Signed-off-by: Maulik Mankad <x0082077@ti.com>
Cc: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes the following NULL pointer dereference issue.
Pointer 'request' returned from call to function 'next_request'
at line 748 may be NULL and may be dereferenced at line 792.
============
Code Snippet
============
748: request = next_request(musb_ep);
785: if (dma && (csr & MUSB_RXCSR_DMAENAB)) {
csr &= ~(MUSB_RXCSR_AUTOCLEAR
| MUSB_RXCSR_DMAENAB
| MUSB_RXCSR_DMAMODE);
musb_writew(epio, MUSB_RXCSR,
MUSB_RXCSR_P_WZC_BITS | csr);
792: request->actual += musb_ep->dma->actual_len;
Signed-off-by: Maulik Mankad <x0082077@ti.com>
Cc: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Since a DMA transfer may need to be kicked off several times to complete,
the DMA start must include the length that has already been transferred.
Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Cc: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Gadget stalling a zero-length SETUP request results in this error message:
SetupEnd came in a wrong ep0stage idle
In order to avoid it, always set the CSR0.DataEnd bit after detecting a zero-
length request. Add the missing '\n' to the error message itself as well...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Acked-by: Anand Gadiyar <gadiyar@ti.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Race condition exists between the cppi_interrupt handler and
davinci_interrupt handler w.r.t completing a TX IO. Since DM646x
has seperate DMA and USB endpoint interrupts cppi_interrupt handler
needs to hold the lock while operating on the endpoint.
Update over previous patch to avoid taking the lock if already
taken. Tested on DM644x, DM355 and DM646x platforms.
Signed-off-by: Swaminathan S <swami.iyer@ti.com>
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Acked-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
On OTG and gadget-only configurations, we need a gadget driver
in order to work properly, so avoid changing operation modes
when there's no gadget driver loaded.
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
When registering gadget driver, the state of the transceiver
must be set from undefined (no gadget) to b_idle.
Module unload sets the transceiver state to undefined state.
After the first load/unload pair, the reset irq will be lost.
Signed-off-by: Arnaud Mandy <ext-arnaud.2.mandy@nokia.com>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This fixes a null-pointer dereference bug.
Signed-off-by: Swaminathan S <swami.iyer@ti.com>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Acked-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Current musb gadget dma code produces the warning:
drivers/usb/musb/musb_gadget.c: In function 'txstate':
drivers/usb/musb/musb_gadget.c:312: warning: comparison of distinct
pointer types lacks a cast
So switch to min_t(size_t, ...).
Signed-off-by: Cliff Cai <cliff.cai@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
probe() already was on __init, so moving remove() to __exit.
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commit 7723de7e19 (USB: musb_gadget: remove
pointless loop) included uncalled for (and incorrect) optimization that
might cause a kernel oops in txstate() -- undo it.
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is a (almost) sort-only patch to sort FTDI device
product ID definitions in new ftdi_sio_ids.h header.
Advantage is that new device ID submissions will now have a specific (sorted)
position - less future merge conflicts.
Compile-tested, based on _current_ mainline git.
Minor checkpatch.pl warnings were eliminated whereever it made sense,
very minor text changes.
Signed-off-by: Andreas Mohr <andi@lisas.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is a strictly move-only patch to relocate all FTDI device
product ID definitions to their own ftdi_sio_ids.h header
(following the usual *_ids.h kernel tree convention, too),
thus correcting the slightly too messy appearance
(crucial driver defines were stuck somewhere in the decaying middle swamp
of the huge existing header).
Compile-tested, based on latest mainline git.
Signed-off-by: Andreas Mohr <andi@lisas.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Fix new kernel-doc warnings in usb core:
Warning(drivers/usb/core/usb.c:79): No description found for parameter 'config'
Warning(drivers/usb/core/usb.c:79): No description found for parameter 'iface_num'
Warning(drivers/usb/core/usb.c:79): No description found for parameter 'alt_num'
Warning(drivers/usb/core/hcd.c:1622): No description found for parameter 'udev'
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Commit 917778267f removed __init from
ehci_wait_for_port(), but left it in place on ehci_reset_port(), which
is being called from the former function.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Acked-by: Jason Wessel <jason.wessel@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
While converting emi62 to use request_firmware(), the driver was also
changed to use the ihex helper functions. However, this broke the loading
of the FPGA firmware because the code tries to access the addr field of
the EOF record which works with a plain array that has an empty last
record but not with the ihex helper functions where the end of the data is
signaled with a NULL record pointer, resulting in:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: [<f80d248c>] emi62_load_firmware+0x33c/0x740 [emi62]
This can be fixed by changing the loop condition to test the return value
of ihex_next_binrec() directly (like in emi26.c).
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Reported-and-tested-by: Der Mickster <retroeffective@gmail.com>
Acked-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch corrects a problem where drivers/usb/otg is linked twice
if CONFIG_USB_ULPI is selected, resulting in a build error (symbol
conflict). The files in that directory are properly linked already
as part of CONFIG_USB, and need not be indicated specifically for
CONFIG_USB_ULPI.
Signed-off-by: Bill Gatliff <bgat@billgatliff.com>
Acked-by: Felipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Use ERR_PTR and IS_ERR rather than mixing integers and pointers.
The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression *E;
@@
* E < 0
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1315) fixes some bugs in the USB core authorization
code:
usb_deauthorize_device() should deallocate the device strings
instead of leaking them, and it should invoke
usb_destroy_configuration() (which does proper reference
counting) instead of freeing the config information directly.
usb_authorize_device() shouldn't change the device strings
until it knows that the authorization will succeed, and it should
autosuspend the device at the end (having autoresumed the
device at the start).
Because the device strings can be changed, the sysfs routines
to display the strings must protect the string pointers by
locking the device.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
CC: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Acked-by: David Vrabel <david.vrabel@csr.com>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch (as1314) renames usb_configure_device() and
usb_configure_device_otg() in the hub driver. Neither name is
appropriate because these routines enumerate devices, they don't
configure them. That's handled by usb_choose_configuration() and
usb_set_configuration().
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
The USB serial code was a new user of the kfifo API, and it was missed
when porting things to the new kfifo API.
Please make the write_fifo in place. Here is my patch to fix the
regression and full ported version.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Reported-and-tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
rename kfifo_put... into kfifo_in... to prevent miss use of old non in
kernel-tree drivers
ditto for kfifo_get... -> kfifo_out...
Improve the prototypes of kfifo_in and kfifo_out to make the kerneldoc
annotations more readable.
Add mini "howto porting to the new API" in kfifo.h
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move the pointer to the spinlock out of struct kfifo. Most users in
tree do not actually use a spinlock, so the few exceptions now have to
call kfifo_{get,put}_locked, which takes an extra argument to a
spinlock.
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a new generic kernel FIFO implementation.
The current kernel fifo API is not very widely used, because it has to
many constrains. Only 17 files in the current 2.6.31-rc5 used it.
FIFO's are like list's a very basic thing and a kfifo API which handles
the most use case would save a lot of development time and memory
resources.
I think this are the reasons why kfifo is not in use:
- The API is to simple, important functions are missing
- A fifo can be only allocated dynamically
- There is a requirement of a spinlock whether you need it or not
- There is no support for data records inside a fifo
So I decided to extend the kfifo in a more generic way without blowing up
the API to much. The new API has the following benefits:
- Generic usage: For kernel internal use and/or device driver.
- Provide an API for the most use case.
- Slim API: The whole API provides 25 functions.
- Linux style habit.
- DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros
- Direct copy_to_user from the fifo and copy_from_user into the fifo.
- The kfifo itself is an in place member of the using data structure, this save an
indirection access and does not waste the kernel allocator.
- Lockless access: if only one reader and one writer is active on the fifo,
which is the common use case, no additional locking is necessary.
- Remove spinlock - give the user the freedom of choice what kind of locking to use if
one is required.
- Ability to handle records. Three type of records are supported:
- Variable length records between 0-255 bytes, with a record size
field of 1 bytes.
- Variable length records between 0-65535 bytes, with a record size
field of 2 bytes.
- Fixed size records, which no record size field.
- Preserve memory resource.
- Performance!
- Easy to use!
This patch:
Since most users want to have the kfifo as part of another object,
reorganize the code to allow including struct kfifo in another data
structure. This requires changing the kfifo_alloc and kfifo_init
prototypes so that we pass an existing kfifo pointer into them. This
patch changes the implementation and all existing users.
[akpm@linux-foundation.org: fix warning]
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'omap-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap-2.6:
OMAP3: serial - fix bug introduced in
mfd: twl: fix twl4030 rename for remaining driver, board files
USB ehci: replace mach header with plat
omap3: Allow EHCI to be built on OMAP3
Replace the mach/usb.h with plat/usb.h
Cc: linux-usb-devel@lists.sourceforge.net
Signed-off-by: Thomas Weber <weber@corscience.de>
Acked-by: Felipe Balbi <felipe.balbi@nokia.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>
