kernel.git/drivers/video/fbdev/udlfb.c, branch linux-4.18.y

udlfb: set line_length in dlfb_ops_set_par

2018-09-09T08:32:41Z

commit 0ac319b7af1bb24a33365d0ec82a2f56a59b2a78 upstream. Set the variable "line_length" in the function dlfb_ops_set_par. Without this, we get garbage if we select different videomode with fbset. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Greg Kroah-Hartman

udlfb: handle allocation failure

2018-09-09T08:32:40Z

commit 080fb5240bdcabed7387b814139c3ea172d59fc5 upstream. Allocations larger than PAGE_ALLOC_COSTLY_ORDER are unreliable and they may fail anytime. This patch fixes the udlfb driver so that when a large alloactions fails, it tries to do multiple smaller allocations. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Greg Kroah-Hartman

udlfb: make a local copy of fb_ops

2018-09-09T08:32:40Z

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 Cc: stable@vger.kernel.org Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Greg Kroah-Hartman

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

2018-09-09T08:32:40Z

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 Cc: stable@vger.kernel.org Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Greg Kroah-Hartman

udlfb: fix display corruption of the last line

2018-09-09T08:32:40Z

commit 4e705e17ce3409a1f492cfd5dadcf6a4f6075842 upstream. The displaylink hardware has such a peculiarity that it doesn't render a command until next command is received. This produces occasional corruption, such as when setting 22x11 font on the console, only the first line of the cursor will be blinking if the cursor is located at some specific columns. When we end up with a repeating pixel, the driver has a bug that it leaves one uninitialized byte after the command (and this byte is enough to flush the command and render it - thus it fixes the screen corruption), however whe we end up with a non-repeating pixel, there is no byte appended and this results in temporary screen corruption. This patch fixes the screen corruption by always appending a byte 0xAF at the end of URB. It also removes the uninitialized byte. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Greg Kroah-Hartman

udlfb: fix semaphore value leak

2018-09-09T08:32:40Z

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 Cc: stable@vger.kernel.org [b.zolnierkie: fix immediatelly -> immediately typo] Signed-off-by: Bartlomiej Zolnierkiewicz Signed-off-by: Greg Kroah-Hartman

video: udlfb: Return an error code only as a constant in dlfb_realloc_framebuffer()

2018-03-28T14:34:27Z

* Return an error code without storing it in an intermediate variable. * Delete the label "error" and local variable "retval" which became unnecessary with this refactoring. Signed-off-by: Markus Elfring Cc: Bernie Thompson Signed-off-by: Bartlomiej Zolnierkiewicz

video: udlfb: Use already defined BPP constant

2018-03-12T16:06:53Z

Replace const variable with already defined constant. Signed-off-by: Ladislav Michl Cc: Bernie Thompson Signed-off-by: Bartlomiej Zolnierkiewicz

video: udlfb: Fix unaligned access

2018-03-12T16:06:53Z

Driver generates lots of alignment trap exceptions on ARM. Fix that by replacing typecasting of odd addresses with byte shifting and remove uneccessary typecasting. Signed-off-by: Ladislav Michl Cc: Bernie Thompson Signed-off-by: Bartlomiej Zolnierkiewicz

video: udlfb: Switch from the pr_() to the dev_() logging functions

2018-01-16T15:35:20Z

Use dev_err() and dev_info() instead of pr_err() and pr_info(). USB device is used as argument to dev_*() functions for probe and urb manipulation, FB device for framebuffer related info. Also noisy device probe output was partly removed as idVendor, idProduct, name and serial are already printed by usb core, and partly turned into debug output. Signed-off-by: Ladislav Michl Cc: Bernie Thompson Signed-off-by: Bartlomiej Zolnierkiewicz

kernel.git/drivers/video/fbdev/udlfb.c, branch linux-4.18.y

udlfb: set line_length in dlfb_ops_set_par

udlfb: handle allocation failure

udlfb: make a local copy of fb_ops

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

udlfb: fix display corruption of the last line

udlfb: fix semaphore value leak

video: udlfb: Return an error code only as a constant in dlfb_realloc_framebuffer()

video: udlfb: Use already defined BPP constant

video: udlfb: Fix unaligned access

video: udlfb: Switch from the pr_*() to the dev_*() logging functions

video: udlfb: Switch from the pr_() to the dev_() logging functions