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The status workqueue is involved in initializing the Uxxx and polling the Uxxx until a supported PCMCIA CardBus device is detected. It then starts the command and respond workqueues and then loads the module that handles the device, after which it just polls the Uxxx looking for card ejects. The command and respond workqueues are involved in implementing a command sequencer for communicating with the firmware on the other side of the FTDI chip in the Uxxx. These workqueues have only a single work item each and hence they do not require ordering. Also, none of the above workqueues are being used on a memory recliam path. Hence, the singlethreaded workqueues have been replaced with the use of system_wq. System workqueues have been able to handle high level of concurrency for a long time now and hence it's not required to have a singlethreaded workqueue just to gain concurrency. Unlike a dedicated per-cpu workqueue created with create_singlethread_workqueue(), system_wq allows multiple work items to overlap executions even on the same CPU; however, a per-cpu workqueue doesn't have any CPU locality or global ordering guarantee unless the target CPU is explicitly specified and thus the increase of local concurrency shouldn't make any difference. The work items have been sync cancelled because they are self-requeueing and need to wait for the in-flight work item to finish before proceeding with destruction. Hence, they have been sync cancelled in ftdi_status_cancel_work(), ftdi_command_cancel_work() and ftdi_response_cancel_work(). These functions are called in ftdi_elan_exit() to ensure that there are no pending work items while disconnecting the driver. Signed-off-by: Bhaktipriya Shridhar <bhaktipriya96@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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sisusbvga | ||
adutux.c | ||
appledisplay.c | ||
chaoskey.c | ||
cypress_cy7c63.c | ||
cytherm.c | ||
ehset.c | ||
emi26.c | ||
emi62.c | ||
ezusb.c | ||
ftdi-elan.c | ||
idmouse.c | ||
iowarrior.c | ||
isight_firmware.c | ||
Kconfig | ||
ldusb.c | ||
legousbtower.c | ||
lvstest.c | ||
Makefile | ||
rio500_usb.h | ||
rio500.c | ||
trancevibrator.c | ||
ucsi.c | ||
ucsi.h | ||
usb3503.c | ||
usb4604.c | ||
usb_u132.h | ||
usblcd.c | ||
usbsevseg.c | ||
usbtest.c | ||
uss720.c | ||
yurex.c |