kernel/git/stable/linux-stable.git/include/video/udlfb.h, branch linux-3.16.y

udlfb: set optimal write delay

2018-12-16T22:08:22+00:00

commit bb24153a3f13dd0dbc1f8055ad97fe346d598f66 upstream. The default delay 5 jiffies is too much when the kernel is compiled with HZ=100 - it results in jumpy cursor in Xwindow. In order to find out the optimal delay, I benchmarked the driver on 1280x720x30fps video. I found out that with HZ=1000, 10ms is acceptable, but with HZ=250 or HZ=300, we need 4ms, so that the video is played without any frame skips. This patch changes the delay to this value. Signed-off-by: Mikulas Patocka Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Ben Hutchings

udlfb: make a local copy of fb_ops

2018-12-16T22:08:22+00:00

commit 2c29cfc3eaf11779176bf41475cfca49bccba11c upstream. The defio subsystem overwrites the method fb_osp->mmap. That method is stored in module's static data - and that means that if we have multiple diplaylink adapters, they will over write each other's method. In order to avoid interference between multiple adapters, we copy the fb_ops structure to a device-local memory. Signed-off-by: Mikulas Patocka Signed-off-by: Bartlomiej Zolnierkiewicz [bwh: Backported to 3.16: Pointer to struct dlfb_data is named "dev" rather than "dlfb"] Signed-off-by: Ben Hutchings

udlfb: don't switch if we are switching to the same videomode

2018-12-16T22:08:22+00:00

commit 564f1807379298dfdb12ed0d5b25fcb89c238527 upstream. The udlfb driver reprograms the hardware everytime the user switches the console, that makes quite unusable when working on the console. This patch makes the driver remember the videomode we are in and avoid reprogramming the hardware if we switch to the same videomode. We mask the "activate" field and the "FB_VMODE_SMOOTH_XPAN" flag when comparing the videomode, because they cause spurious switches when switching to and from the Xserver. Signed-off-by: Mikulas Patocka Signed-off-by: Bartlomiej Zolnierkiewicz [bwh: Backported to 3.16: Pointer to struct dlfb_data is named "dev" rather than "dlfb"] Signed-off-by: Ben Hutchings

udlfb: fix semaphore value leak

2018-12-16T22:08:21+00:00

commit 9d0aa601e4cd9c0892f90d36e8488d79b72f4073 upstream. I observed that the performance of the udl fb driver degrades over time. On a freshly booted machine, it takes 6 seconds to do "ls -la /usr/bin"; after some time of use, the same operation takes 14 seconds. The reason is that the value of "limit_sem" decays over time. The udl driver uses a semaphore "limit_set" to specify how many free urbs are there on dlfb->urbs.list. If the count is zero, the "down" operation will sleep until some urbs are added to the freelist. In order to avoid some hypothetical deadlock, the driver will not call "up" immediately, but it will offload it to a workqueue. The problem is that if we call "schedule_delayed_work" on the same work item multiple times, the work item may only be executed once. This is happening: * some urb completes * dlfb_urb_completion adds it to the free list * dlfb_urb_completion calls schedule_delayed_work to schedule the function dlfb_release_urb_work to increase the semaphore count * as the urb is on the free list, some other task grabs it and submits it * the submitted urb completes, dlfb_urb_completion is called again * dlfb_urb_completion calls schedule_delayed_work, but the work is already scheduled, so it does nothing * finally, dlfb_release_urb_work is called, it increases the semaphore count by 1, although it should increase it by 2 So, the semaphore count is decreasing over time, and this causes gradual performance degradation. Note that in the current kernel, the "up" function may be called from interrupt and it may race with the "down" function called by another thread, so we don't have to offload the call of "up" to a workqueue at all. This patch removes the workqueue code. The patch also changes "down_interruptible" to "down" in dlfb_free_urb_list, so that we will clean up the driver properly even if a signal arrives. With this patch, the performance of udlfb no longer degrades. Signed-off-by: Mikulas Patocka [b.zolnierkie: fix immediatelly -> immediately typo] Signed-off-by: Bartlomiej Zolnierkiewicz [bwh: Backported to 3.16: Pointers to struct dlfb_data are named "dev" rather than "dlfb"] Signed-off-by: Ben Hutchings

udlfb: fix hcd_buffer_free panic on unplug/replug

2012-03-02T01:46:27+00:00

Fix race conditions with unplug/replug behavior, in particular take care not to hold up USB probe/disconnect for long-running framebuffer operations and rely on usb to handle teardown. Fix for kernel panic reported with new F17 multiseat support. Reported-by: Kay Sievers Signed-off-by: Bernie Thompson

udlfb: add more comprehensive support for DPMS FB_BLANK_* modes

2011-08-24T10:07:59+00:00

Fixes earlier problems where monitor would not return from blank Test with any DisplayLink-based USB 2.0 graphics adapter sudo nano /sys/class/graphics/fb?/blank and write out single digit FB_BLANK_* code from include/linux/fb.h Supports on (0), blank (1), suspend (2,3), powerdown (4) Signed-off-by: Bernie Thompson Signed-off-by: Florian Tobias Schandinat

video: udlfb: Kill off special printk wrappers, use pr_fmt().

2011-01-06T09:07:54+00:00

This kills off all of the dl_xxx() printk wrappers and simply stubs in a pr_fmt() definition to accomplish the same thing. Signed-off-by: Paul Mundt

video: udlfb: Kill off some magic constants for EDID sizing.

2011-01-06T09:04:02+00:00

The edid length is fixed, so use the standard definition consistently. Signed-off-by: Paul Mundt

fbdev: move udlfb out of staging.

2010-11-16T05:00:24+00:00

udlfb has undergone a fair bit of cleanup recently and is effectively at the point where it can be liberated from staging purgatory and promoted to a real driver. The outstanding cleanups are all minor, with some of them dependent on drivers/video headers, so these will be done incrementally from udlfb's new home. Requested-by: Bernie Thompson Signed-off-by: Paul Mundt