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Christian Fredrik Kalager Schaller
Works at Red Hat Software
Lives in Westford, MA, USA
495 followers|292,323 views
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Important Update on @fedora 25 Hybrid Graphics Support from Hans - http://hansdegoede.livejournal.com/16668.html
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Donald Trump got elected president of the USA despite losing the popular vote to Hillary 47.5% to 47.7%. Why is he not screaming about the system being rigged ?! :) 
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Jiří Eischmann's profile photoRob Clark's profile photoDavid Gerber's profile photo
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New blog entry with a lot of information about hybrid graphics in Fedora!!
When we started the Fedora Workstation effort one thing we wanted to do was to drain the proverbial swamp of make sure that running Linux on a laptop is a first rate experience. As you see from my last blog entry we have been working on building a team dedicated to that task.
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Adrian Bradshaw's profile photoChristian Fredrik Kalager Schaller's profile photoSubhendu Ghosh's profile photo
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Great job!
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Really missing the wife and kids while they are away, but it is nice to get beautiful photos like this showing that the kids are doing fine at their grandparents place :) Big kudos to the photographer +Qurat-ul-Ain Tabassum!
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Interesting article. These concurring opinions doesn't set any presedence etc., but it does mean that a company or a group could try to put some important software patents 'on trial' and get it in front of these judges and have a decent chance of success or at least diminish software patents even more.
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A little thing I been working on for the last year to make happen :)
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Christian Fredrik Kalager Schaller's profile photoArc Riley's profile photoAndreas Tunek's profile photo
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+Christian Fredrik Kalager Schaller It would be really nice if you could make that legal resarch public so people could be better informed regarding patents.
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Help Peter improve libinput by answering his question :)
 
Unhappy with libinput's touchpad pointer acceleration? What laptop do you have?
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Flatpak cross-compilation support: Epilogue
You might remember my attempts at getting an easy to use cross-compilation for ARM applications on my x86-64 desktop machine. With Fedora 25 approaching, I'm happy to say that the necessary changes to integrate the feature have now rolled into Fedora 25. Fo...
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Anyone know a linux friendly person at HTC who you could put me in touch with? Wish to have some discussions with them about various open source topics.
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Sorry, no contacts there.
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For the next Fedora release, 25, I've been working on this tool that's supposed to help (especially new users, especially on other platforms than Linux) getting Fedora images on your flash drive.

So if you think that's a good idea and would like to help out, please try running the tool and get back to me with your hints what should be better. I'll be most grateful.

There are links to Windows and Mac builds in the Releases section, so is a Flatpak build. In case you're running Fedora, it's packaged as "mediawriter".
MediaWriter - Fedora Media Writer
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PSA: Just because a Vulkan application works ok on one driver (or version of a driver) and not on another doesn't mean that driver is broken.

This is something I hear all the time: "The Intel driver is broken because X app doesn't work". In my experience debugging these issues, I have see about as many (maybe more?) application bugs than bugs in our driver. Frequently, there are bugs on both sides that have to get fixed before an application will work. How does this happen? Part of the reason is that Vulkan is a new API and things are still maturing, but there's more to it than that.

One of the things about Vulkan that's different from GL is that it requires the application to pass in a lot of redundant or possibly unneeded information. No Vulkan implementation needs 100% of the information the client provides so some of it will get thrown away. If the application is missing some of this information or if it is inconsistent in any way, this can easily cause the application to fail on one driver and work on another without either driver having a bug. The solution to this is a set of validation layers that application developers are supposed to use when developing their application. These layers cross-check the information provided by the application and try to ensure that they provide all of the needed information and that it's consistent. Unfortunately, those layers are somewhat incomplete and application bugs of this type still leak through. The layers are constantly improving, but there are still bits and pieces missing.

There are also driver bugs. Our driver, I'm sure, still has a lot of them. In order to try and improve driver quality and keep the bugs down, the Khronos group has been developing a test suite called the Vulkan CTS. Driver writers are expected to run and pass these tests if they want to ship a driver and call it conformant. Unfortunately, the test suite still has a lot of coverage holes and driver bugs can easily go unnoticed. With GL, the situation is a bit different. There are a multiple test suites out there and also a huge number of applications that are exercising many driver paths that the tests don't. With Vulkan, there are only a few of Vulkan applications that run on Linux so we basically have to rely on the CTS for ensuring that our driver works correctly.

So how do all of these applications run on AMD and NVIDIA out-of-the box? If the driver and validation situation is so bad, how does anything work? Well, first off, it's not that bad, and it's improving every day. But the real answer is, "lots of testing." Most applications (especially games) are primarily developed and tested against AMD and NVIDIA's implementations (and sometimes Quallcom because they support Android) so they naturally work there. Also, all of the driver teams are pulling applications and testing them to try and find bugs in the applications and their drivers and get them fixed as quickly as possible. Some driver teams have more time available for this sort of preemptive debugging than others.

What can you do as an app developer or user? First, if you find bugs, report them. We are dedicated to making our Vulkan driver as good as it can be but we can't fix bugs we don't know about. One of the most frustrating things for me as a driver developer is to see users complaining on internet forums about how our driver is crap because it has some bug and doesn't run their favorite app but they've never bothered to report it. Second, have patience and update regularly. When we come across applications that don't work, we try to get the bugs, whether in our driver or in the application, resolved as quickly as we can. However, it takes time to get the bugs resolved and for driver and application updates to get pushed out.

Finally, please use our driver! The more Vulkan applications that are out there and the more people we have running them on our driver, the better it will be.
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Interesting writeup :)
Recently I was looking to install an application on Linux with a large number of dependencies: TeXstudio and it’s TeXLive libraries. I wasn’t sure I wanted the packages sitting around on my computer long term, and I didn’t fe...
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Currently
Westford, MA, USA
Previously
Lowell, MA, USA - Brno, Czech Republic - Cambridge, United Kingdom - Barcelona, Spain - Oslo, Norway
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  • Red Hat Software
    Senior Manager, present
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