aboutsummaryrefslogtreecommitdiff
path: root/drivers/media/video/cx18
AgeCommit message (Collapse)Author
2008-12-30V4L/DVB (9937): cx18: Use a consistent crystal value for computing all PLL ↵Andy Walls
parameters Use a consistent crystal value of 28.636360 MHz for computing all PLL parameters so clocks don't have relative error due to assumed crystal value mismatches. Also aimed to have all PLLs run their VOCs at close to 400 MHz to minimze the error of these PLLs as frequency synthesizers. Also set the VDCLK and AIMCLK PLLs to sane values before the APU and CPU firmware are loaded. Also fixed I2S Master clock dividers. Many thanks to Mike Bradley and Jeff Campbell for reporting this problem and suggesting the solution, researching and experimenting, and performing extensive testing to support their suggested solution. Reported-by: Jeff Campbell <jac1dlists@gmail.com> Reported-by: Mike Bradley <mike.bradley@incanetworks.com> Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9936): cx18: Disable locking of Video and Audio PLL for analog capturesAndy Walls
Disable AV_LOCK, locking of audio PLL to video PLL in the cx18-av-core for analog captures. It seems to have adverse effects on captures from SVideo and CVBS sources with current clock & crystal settings in the driver. Many thanks to Jeff Campbell and Mike Bradley for reporting this problem, and suggesting the solution and performing extensive testing to support their suggestion. Reported-by: Jeff Campbell <jac1dlists@gmail.com> Reported-by: Mike Bradley <mike.bradley@incanetworks.com> Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9895): cx18: Refine the firmware load and firmware startup processAndy Walls
Refine the firmware load and firmware startup process. Significant changes are to ensure the SCB and IPC area are correct before starting up the firmware, and letting the CPU firmware start up the APU firmware for us. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9894): cx18: Use a known open task handle when setting stream ↵Andy Walls
CX2341x parameters cx18: Use a known open task handle when setting stream CX2341x parameters Sometimes, we might only have VBI or YUV stream open instead of an MPEG stream. Let's make sure we use a valid task handle to perform the CX2341x control settings. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9893): cx18: Convert some list manipulations to emphasize entries ↵Andy Walls
not lists Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9892): cx18: VBI comment corrections and comments about VBI issuesAndy Walls
VBI comment corrections to avoid future confusion about standards. Comments on cx18 VBI implementation shortcomings that need resolution. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9891): cx18 Replace magic number 63 with CX18_MAX_FW_MDLS_PER_STREAMAndy Walls
Removed magic number that referred to firmware limit on the number of MDLs the firmware can maintain for any stream at any one time. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9806): cx18: Enable raw VBI captureAndy Walls
A combined authorship patch from Hans Verkuil and Andy Walls. Raw VBI can now be captured but requires a video capture to be in progress as well. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9805): cx18: Port fix for raw/sliced VBI mixup from ivtv and cx25840Andy Walls
This is a port of the fixes Hans Verkuil made for ivtv/cx25840: The service_set field was used to determine whether raw or sliced VBI was desired. This is incorrect since it is perfectly valid to select sliced VBI with a service_set of 0. Instead the driver should check on VIDIOC_S_FMT whether the type field matches the raw or sliced VBI type. Updated the cx18 driver accordingly, including an additional check in cx18_start_v4l2_encode_stream() that didn't exist in ivtv. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9804): cx18: Avoid making firmware API calls with the queue lock heldAndy Walls
cx18: Avoid making firmware API calls with the queue lock held. The source of MPEG strem corruption when not holding the queue lock was found to be that the MPEG buffer could be retrieved by the user app before it was sync'ed for the host cpu. Incoming buffers are now sync'ed before being put on q_full and releasing the queue lock. We can thus avoid the sometimes lengthy call to the firmware for CPU_DE_SET_MDL while holding the queue lock, so we can get better performance. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9803): cx18: Increment version number due to siginificant buffering ↵Andy Walls
changes cx18: Increment version number due to siginificant buffering changes. Now version 1.0.4 Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9802): cx18: Add module parameters for finer control over buffer ↵Andy Walls
allocations cx18: Add module parameters for finer control over buffer allocations. User now has the option of setting smaller buffers to get lower latency transfers from the encoder. User can also now set the number of buffers used for a stream explicitly. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9801): cx18: Allow more than 63 capture buffers in rotation per streamAndy Walls
cx18: Allow more than 63 capture buffers in rotation per stream. Implement q_busy to hold buffers the firmware has for use. q_free holds truly unused buffers in a pool. New buffers are given to the firmware as soon as the firmware returns one, if there are any to give to the firmware. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9800): cx18: Eliminate q_io from stream buffer handlingAndy Walls
Eliminate q_io from stream buffer handling in anticipation of upcoming changes in buffer handling. q_io was a holdover from ivtv and it's function in cx18 was trivial and not necessary. We just push things back onto the front of q_full now, instead of maintaining a 1 buffer q_io queue. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9778): cx18: cx18_writel_expect() should not declare success on a ↵Andy Walls
PCI read error cx18: cx18_writel_expect() should not declare success on a PCI read error. This removes the potential for cx18_write*_expect() calls to not accomplish a PCI write successfully as expected. The CX18-AV core uses the *expect() calls often and this may be the source of intermittent audio problems and standands switching problems. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9776): cx18: Change to per CX23418 device work queues for ↵Andy Walls
deferrable work handling cx18: Change to per CX23418 device work queues for deferrable work handling. Needed to support 2.6.22 and earlier kernels that can't selectively cancel work orders. Also will provide slightly better performance on SMP systems. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9730): cx18: Quiet a sometimes common warning that often has benign ↵Andy Walls
consequences cx18: Quiet a sometimes common warning that often has benign consequences. No one probably cares that the firmware took forever to ack our command, as they always seem to succeed whether or not the firmware acks it in a reasonable amount of time. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9729): cx18: Update version due to significant irq handling changesAndy Walls
Update the version number due to significant changes in the way the mailboxes and interrupts are handled. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9728): cx18: Copyright attribution update for files modified by awallsAndy Walls
Add copyright attribution for files modified by awalls in 2008 Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9727): cx18: Adjust outgoing mailbox timeouts and remove statistics ↵Andy Walls
logging cx18: Adjust outgoing mailbox timeouts and remove statistics logging. This saves some wasted storage in struct cx18 for each card. Cutting the outgoing mailbox timeouts in half from the previous value appears to be safe with MythTV. Got rid of interrupted case code path after a wait uninterruptable returns. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9726): cx18: Restore buffers that have fallen out of the transfer ↵Andy Walls
rotation Restore buffers that have fallen out of the transfer rotation, and check for coherent mailbox data when processing a stale mailbox. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9725): cx18: Remove unnecessary MMIO accesses in time critical irq ↵Andy Walls
handling path Remove unnecessary MMIO accesses in time critical irq handling path. Also ensured that the mailbox ack field is read in last, so we know for sure if we have a stale mailbox or not on receipt. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9724): cx18: Streamline cx18-io[ch] wrappers and enforce MMIO retry ↵Andy Walls
strategy cx18: Streamline cx18-io[ch] wrappers and enforce MMIO retry strategy so that write retries always occur and read retries never occur (as they never help). Remove MMIO statistics logging to speed up MMIO accesses. Deprecate & ignore retry_mmio and mmio_ndelay module parameters, to essentially force retry_mmio=1 and mmio_ndelay=0. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9723): cx18: Propagate staleness of mailbox and mdl ack data to ↵Andy Walls
work handler cx18: Propagate staleness of mailbox and mdl ack data to work handler to let the work handler know that the data from the encoder may not be coherent. Allows for smarter handling of buffers in future, to deal with MDLs that fall out of rotation due to irq handler being late in collecting mailbox and mdl ack info. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9722): cx18: Convert per stream queue spinlocks into mutexesAndy Walls
Convert the per stream queue spinlocks into mutexes. All queue manipulation happens via the work queue or system calls into the driver, and not in an interrupt context. This reduces the amout of time the cx18 driver keeps interrupts disabled. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9721): cx18: Change to singlethreaded global work queue thread for ↵Andy Walls
deferable work Change to singlethreaded global work queue thread for deferable work, instead of the kernel default multithreaded work queue. This ensures execution of deferable work is always in the proper order, so caputred buffers don't get reordered. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9720): cx18: Major rewrite of interrupt handling for incoming ↵Andy Walls
mailbox processing A major rewrite of interrupt handling for incoming mailbox processing, to split the timing critical steps from the the deferrable steps as the sending XPU on the CX23418 will time out and overwrite our incoming mailboxes rather quickly. Setup a pool of work "order forms" for the irq handler to send jobs to the new work handler routine which uses the kernel default work queue to do the deferrable work. Started optimizing some of the cx18-io calls as they are now the low hanging fruit for recoving microseconds back from the timeline. Future optimizations will get rid of mmio read retries, mmio stats logging, and combine smaller functions in the irq path into the larger ones to save ~2 us each. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9599): cx18: Fix unitialized variable problem upon APU firmware ↵Andy Walls
file read failure If APU firmware file read failed, the jump vector to the APU was undefined and the APU would be started executing garbage. Fix uninitialized variable to be an infinite loop for the APU, but also bail out before even starting the APU. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9598): cx18: Prevent CX23418 from clearing it's outgoing ack ↵Andy Walls
interrupts to driver When the CX23418 CPU unit sent out an ack interrupt to the linux driver, it also received that interrupt and cleared the flag before the linux driver could see what the interrupt was for. This fix prevents the CPU from receiving an IRQ for it's own outgoing ack's to the linux driver. This fix is critical now that the linux driver doesn't poll but relies on these ack interrupts. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9597): cx18: Minor fixes to APU firmware load processAndy Walls
Use the APU fw start address from rom file instead of a hardcoded entry vector. Fixed cx18_setup_page() calls to use the correct APU image load addresses. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9596): cx18: Further changes to improve mailbox protocol integrity ↵Andy Walls
& performnce All waits for cx18 mailbox API commands are now uninterruptable. Added code to collect mailbox ack statistics. Tweaked timeouts based on collected stats and video vertical frame and field rates. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9595): cx18: Improve handling of outgoing mailboxes detected to be busyAndy Walls
cx18: Improve handling of outgoing mailboxes detected to be busy. When encountering a busy mailbox, sleep instead of polling, and wait for interrupt or timeout. If the mailbox is still busy, force it free. When sending commands, make sure we never create a situation where we mark the mailbox busy upon sending, and ensure we always have a method to cleanly recover from a busy mailbox. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9594): cx18: Roll driver version number due to significant changesAndy Walls
Driver interrupt and mailbox handling has change significantly. Time for a roll to v1.0.2. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9593): cx18: Add outgoing mailbox mutexes and check for ack via ↵Andy Walls
waitq vs poll Add mutexes to ensure exclusive access for outgoing driver to CX23418 mailboxes. Also wait on a waitq for mailbox acknowledgement from the CX23418 instead of polling. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9592): cx18: Use default kernel work queue; fix streaming flag for ↵Andy Walls
work handler cx18: Use default kernel work queue; fix streaming flag for work handler. Eliminate cx18 specific work queue and use the kernel default work queue. Fixed the F_STREAMING_FLAG for the TS stream so cx18_dvb_work_handler() can know when it is not safe to send MDLs to the firmware. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-30V4L/DVB (9513): cx18: Reduce number of mmio read retriesAndy Walls
cx18: Reduce number of mmio read retries to improve performance. Experiments have shown 2 things: read retries never improve the result of a suspect mmio read from the CX23418 (the result stays all 0xff's), and that most of the suspected read failures are actually proper reads of values that should be all 0xff's. This change reduces the number of read retries and keeps the count separate from write retries. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-29V4L/DVB (9514): cx18: Fix PLL freq computation for debug displayAndy Walls
cx18: Fix PLL freq computation for debug display. The code to compute the PLL freq from register values was storing an intermediate 56 bit result in a 32 bit type, causing a nonsense value to be displayed. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-29V4L/DVB (9512): cx18: Fix write retries for registers that always change - ↵Andy Walls
part 3. cx18: Fix write retries for registers that always change - part 3. Fix the io for the rest of the registers that will often not read back the value just written. Modified register readback checks to make sure the intended effect was achieved without constantly rewriting the registers. The one outstanding register remaining is 0xc72014 CX18_AUDIO_ENABLE, whose behavior on writes I have yet to determine. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-29V4L/DVB (9474): cx18: Remove redundant block scope variable in cx18_probe() ↵Andy Walls
for sparse cx18: Remove redundant block scope variable in cx18_probe() to eliminate sparse build warning. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-12-16V4L/DVB (9885): drivers/media Kconfig's: fix bugzilla #12204Mauro Carvalho Chehab
When the tuner modules were moved to common/tuners, a separate customize option were added for tuners. However, the automatic selection of the tuners were still using the older option. This causes that the automatic selection to fail, if DVB_FE_CUSTOMISE is selected. Also, since those tuners are now under MEDIA_TUNER_CUSTOMIZE menu, if you unset MEDIA_TUNER_CUSTOMIZE, you can't manually select the tuners. This patch fixes this error by replacing DVB_FE_CUSTOMISE by MEDIA_TUNER_CUSTOMIZE on all places were a tuner is selected. The patch were generated by this small script: for i in `find drivers/media -name Kconfig`; do cat $i|perl -ne 's/(MEDIA_TUNER.*)DVB_FE_CUSTOMISE/\1MEDIA_TUNER_CUSTOMIZE/; print $_' >a mv a $i done Also, manually reordered the tuner entries. Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-11-11V4L/DVB (9516): cx18: Move DVB buffer transfer handling from irq handler to ↵Andy Walls
work_queue cx18: Move DVB buffer transfer handling from irq handler to work_queue thread. In order to properly lock the epu2cpu mailbox for driver to CX23418 commands, the DVB/TS buffer handling needs to be moved from the IRQ handler and IRQ context to a work queue. This work_queue implmentation is strikingly similar to the ivtv implementation - for better or worse. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-11-11V4L/DVB (9515): cx18: Use correct Mailbox IRQ Ack values and misc IRQ ↵Andy Walls
handling cleanup cx18: Use correct Mailbox IRQ Ack values and misc IRQ handling cleanup. The SCB field definitions for Ack IRQ's for mailboxes were inconsistent with the bitmasks being loaded into those SCB fields and the SW2 Ack IRQ handling logic. Renamed fields in SCB to make things consistent and did misc IRQ handling cleanups: removing legacy ivtv dma_reg_lock, HPU IRQ flags, etc. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-11-11V4L/DVB (9511): cx18: Mark CX18_CPU_DE_RELEASE_MDL as a slow API callAndy Walls
cx18: Mark CX18_CPU_DE_RELEASE_MDL as a slow API call. Give the encoder time to complete the MDL release before destroying the encoder internal task. This avoids an encoder lockup on the next digital capture and error messages about buffers being returned for an inactive encoder task handle. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-11-11V4L/DVB (9510): cx18: Fix write retries for registers that always change - ↵Andy Walls
part 2. cx18: Fix write retries for registers that always change - part 2. Some registers, especially interrupt related ones, will never read back the value just written. Modified interrupt register readback checks to make sure the intended effect was achieved. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-11-11V4L/DVB (9506): ivtv/cx18: fix test whether modules should be loaded or not.Hans Verkuil
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-11-11V4L/DVB (9475): cx18: Disable write retries for registers that always change ↵Andy Walls
- part 1. cx18: Disable write retries for registers that always change - part 1. Interrupt related registers will likely not read back the value we just wrote. Disable retries for these registers for now to avoid accidently discarding interrupts. More intelligent read back verification criteria are needed for these and other registers (e.g. GPIO line registers), which will be addressed in subsequent changes. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-10-21V4L/DVB (9299): cx18: Don't mask many real init error codes by mapping them ↵Andy Walls
to ENOMEM Changes to let error return codes bubble up to the user visible error message on card initialization. A number of them were being remapped to ENOMEM when no memory or array resource shortage existed. That hampered diagnosis of user trouble reports. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-10-21V4L/DVB (9298): cx18: Add __iomem address space qualifier to ↵Andy Walls
cx18_log_*_retries() argument cx18: Add __iomem address space qualifier to cx18_log_*_retries() addr argument to clean up sparse build warnings. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-10-21V4L/DVB (9297): cx18: Fix memory leak on card initialization failureAndy Walls
On error exit, the cx18_probe() function did not use the proper entry in cx18_cards[] with kfree() when card init failed; leaking memory. Signed-off-by: Andy Walls <awalls@radix.net> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
2008-10-20byteorder: remove direct includes of linux/byteorder/swab[b].hHarvey Harrison
A consolidated implementation will provide this generically through asm/byteorder, remove direct includes to avoid breakage when the changeover to the new implementation occurs. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Acked-by: Mauro Carvalho Chehab <mchehab@infradead.org> Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>