On Saturday 05 September 2015 15:06:35 Warner Losh wrote: > On Sat, Sep 5, 2015 at 2:58 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > > On Friday 04 September 2015, Warner Losh wrote: > > I understood what you were proposing. It wasn't a lack of understanding > that lead me to the opinion that it was a horrible policy. Despite your > lengthy explanation, you did nothing to address the very simple and common > use case of having identical hardware that none-the-less needs different > firmware which was my basis of the horrible brand I put on this policy. You must be thinking of different examples of firmware files than I am. We have tons of drivers that need firmware, and the reasons for picking a particular file over another alternative tend to be slightly different (most of the time, you just want the latest version). Can you name a specific example you are thinking of where you want different firmware to be loaded on systems with identical hardware? > Also, firmware comes from vendors generally named something other > than FDT compat strings. Renaming firmware generally is also a > horrible policy that most shops frown on. It hampers traceability from > a deployed system back to the sources, for one and introduces one > more place for an 'oops' rename to go undetected until the firmware > is deployed. Most firmware that I can think of does not even come as a file in the format that Linux wants, often there is some vendor source code with firmware in a header file, or you dissect a windows binary driver to pull out the right bits. The file name gets fixed at the point at which the binary is included in the linux-firmware git tree. > So there needs to be a standardized way to augment local policy > to say 'the firmware you need for this node so that the system behaves > as expect in the DT is Y.' Why is that even something that is known by the boot loader? If the boot loader just knows what hardware you have, but a particular instance requires some other device firmware, that sounds like the system administrator would just put the special firmware file in a known location on the local file system (preferably not the same file name as the generic one). Arnd -- To unsubscribe from this list: send the line "unsubscribe devicetree-spec" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
