Linux kernel 5.8 & Desktop Video 11.6

Desktop Video works with kernel 5.6/7 but fails to build with with kernel 5.8.

Code: Select all

/var/lib/dkms/blackmagic/11.6a26/build/blackmagic_lib.c:674:31: error: ‘struct mm_struct’ has no member named ‘mmap_sem’; did you mean ‘mmap_base’?
  down_read(&current_task->mm->mmap_sem);
                               ^~~~~~~~
                               mmap_base
/var/lib/dkms/blackmagic/11.6a26/build/blackmagic_lib.c:695:29: error: ‘struct mm_struct’ has no member named ‘mmap_sem’; did you mean ‘mmap_base’?
  up_read(&current_task->mm->mmap_sem);
                             ^~~~~~~~
                             mmap_base

Looking forward to a fix.

Same here, openSUSE Tumbleweed on a Ryzen9 using a DeckLink Quad HDMI.

As per https://lkml.org/lkml/2020/6/4/180, I tried the following patch:

Code: Select all

nettings@roman:/var/lib/dkms/blackmagic/11.6a26/source> diff -urN blackmagic_lib.c~ blackmagic_lib.c
--- blackmagic_lib.c~   2020-07-09 12:08:00.000000000 +0200
+++ blackmagic_lib.c   2020-08-12 23:00:32.454094733 +0200
@@ -671,7 +671,8 @@
    else
       write = 0;
    
-   down_read(&current_task->mm->mmap_sem);
+//   down_read(&current_task->mm->mmap_sem);
+   mmap_read_lock(current_task->mm);
 #if KERNEL_VERSION_OR_LATER(4, 10, 0)
       if (current_task == current)
          ret = get_user_pages((unsigned long)ptr & PAGE_MASK, *nr_pages, write ? FOLL_WRITE : 0, pages, NULL);
@@ -692,8 +693,9 @@
 #else
       ret = get_user_pages(current_task, current_task->mm, (unsigned long)ptr & PAGE_MASK, *nr_pages, write, 0, pages, NULL);
 #endif
-   up_read(&current_task->mm->mmap_sem);
-   
+//   up_read(&current_task->mm->mmap_sem);
+   mmap_read_unlock(current_task->mm);
+      
    if (ret < (long)*nr_pages)
    {
       dl_unmap_user_pages(pages, *nr_pages, 0);


The file in question now builds, but the dkms build bails out with

Code: Select all

DKMS make.log for blackmagic-11.6a26 for kernel 5.8.0-1-default (x86_64)
Wed 12 Aug 2020 11:00:37 PM CEST
make -C /lib/modules/5.8.0-1-default/build M=/var/lib/dkms/blackmagic/11.6a26/build
make[1]: Entering directory '/usr/src/linux-5.8.0-1-obj/x86_64/default'
  AR      /var/lib/dkms/blackmagic/11.6a26/build/built-in.a
  CC [M]  /var/lib/dkms/blackmagic/11.6a26/build/blackmagic_serial.o
  CC [M]  /var/lib/dkms/blackmagic/11.6a26/build/blackmagic_core.o
  CC [M]  /var/lib/dkms/blackmagic/11.6a26/build/blackmagic_lib.o
  SHIPPED /var/lib/dkms/blackmagic/11.6a26/build/bmd-support.o
  CC [M]  /var/lib/dkms/blackmagic/11.6a26/build/blackmagic_dma.o
  CC [M]  /var/lib/dkms/blackmagic/11.6a26/build/blackmagic_gate.o
  LD [M]  /var/lib/dkms/blackmagic/11.6a26/build/blackmagic.o
  MODPOST /var/lib/dkms/blackmagic/11.6a26/build/Module.symvers
/var/lib/dkms/blackmagic/11.6a26/build/.bmd-support.o.cmd: No such file or directory
make[3]: *** [/usr/src/linux-5.8.0-1/scripts/Makefile.modpost:116: /var/lib/dkms/blackmagic/11.6a26/build/Module.symvers] Error 1
make[2]: *** [/usr/src/linux-5.8.0-1/Makefile:1683: modules] Error 2
make[1]: *** [../../../linux-5.8.0-1/Makefile:185: __sub-make] Error 2
make[1]: Leaving directory '/usr/src/linux-5.8.0-1-obj/x86_64/default'
make: *** [Makefile:43: all] Error 2


I'm new to dkms, but I would expect the fix to be obvious to someone who isn't Help appreciated.

This is on a Ryzen 9 system running openSUSE Tumbleweed with Kernel 5.8.0 and a Decklink Quad HDMI.

Ok, what I guess happens is that Blackmagic ships part of their modules as binary blobs named bmd-support.o_shipped and blackmagic.o_shipped.

Next guess: they are postfixed "_shipped" to protect them from "make clean".

Next gues: The kernel makefiles want to create .foo.cmd files, and somehow this fails for the binary blobs. But there is nothing to do for those pre-built files, they just make the build process barf.

Hack: create empty .foo.cmd files for all binary blobs by modifiying the Makefile for both modules, like so:

Code: Select all

roman:/usr/src/blackmagic-11.6a26 # diff -urB Makefile~ Makefile
--- Makefile~   2020-07-09 12:07:50.000000000 +0200
+++ Makefile   2020-08-13 13:41:54.660894689 +0200
@@ -40,6 +40,7 @@
 PWD       := $(shell pwd)
 
 all:
+   touch .bmd-support.o.cmd
    $(MAKE) -C $(KERNELDIR) M=$(PWD)
 
 clean:
roman:/usr/src/blackmagic-11.6a26 # cd ../blackmagic-io-11.6a26/
roman:/usr/src/blackmagic-io-11.6a26 # diff -urB Makefile~ Makefile
--- Makefile~   2020-07-09 12:07:50.000000000 +0200
+++ Makefile   2020-08-13 13:44:36.589472617 +0200
@@ -43,6 +43,7 @@
 PWD       := $(shell pwd)
 
 all:
+   touch .blackmagic.o.cmd
    $(MAKE) -C $(KERNELDIR) M=$(PWD)
 
 clean:


After this, I can successfully run

Code: Select all

sudo dkms build blackmagic/11.6a26
sudo dkms build blackmagic-io/11.6a26


The modules load ok after that. Further testing later today.
I hope that this information will enable the Blackmagic team to come up with proper support for 5.8 soon.

I also use the openSUSE Tumbleweed with Kernel 5.8. Thank nettings - the all of your suggestions works very well!

Should have mentioned that you can then install the successfully built modules with

Code: Select all

sudo dmks install blackmagic/11.6a26
sudo dkms install blackmagic-ui/11.6a26


Quick testing shows that the modules load ok, but for some reason I only see device 1 and 4. Will investigate further.

Glad to see that you've made some progress on this!

Unfortunately I've had to pull the DeckLink Quad HDMI from our system since it's bugged on Threadripper sTRX4. It's a $500 brick at the moment.

No ETA on a fix but I've started switching things over to NDI.

Hey,

Also experiencing issues with kernel 5.8 on Fedora boxes. Just out of curiosity: what kind of setup (hardware and software) are you using for your switch towards NDI?

Thanks!

OBS NDI. Couple of Dell 3010 boxes feeding thought a CSS326-24G-2S+RM then coming into a Thread Ripper 1920X over the 10G fibre link.

Good Day All,

Developers are aware of this issues and working on an upcoming Fix.

I suggest contacting them for official support.

I am running Fedora 32, Kernel 5.8.4-200 on a 32 Core HPZ820 160GB Ram, Intensity Pro 4K, Quadro RTX4000, 2TB HP Turbo Z Drive
For Media.


Sent from my iPhone using Tapatalk

This saved me a lot of time. Suggested patches worked beautifully. Thank you!

Hello I am running Pop!OS and I have used the debian packages that come with desktop 11.7 and it installed fine but does not see the Decklink 4K mini out card

here is what i see by running dkms status - and it looks like that it is installed fine. When I open the GUI app I don't see any devices recognized

filmtools@pop-os:~$ dkms status
blackmagic, 11.7a12, 5.8.0-7630-generic, x86_64: installed
blackmagic-io, 11.7a12, 5.8.0-7630-generic, x86_64: installed
nvidia, 455.38, 5.8.0-7630-generic, x86_64: installed
system76, 1.0.11~1606243918~20.10~0ca551b, 5.8.0-7630-generic, x86_64: installed
system76_acpi, 1.0.2~1600812457~20.10~0bc966c, 5.8.0-7630-generic, x86_64: installed (original_module exists)
system76-io, 1.0.1~1559663713~20.10~ea5f61a, 5.8.0-7630-generic, x86_64: installed