Hi Peter, Am Dienstag, 4. April 2023, 14:52:02 CEST schrieb Peter Geis: > On Tue, Apr 4, 2023 at 3:55 AM Heiko Stübner <heiko@xxxxxxxxx> wrote: > > > > Hi, > > > > Am Montag, 3. April 2023, 19:59:37 CEST schrieb Javier Martinez Canillas: > > > This baud rate is set for the device by mainline u-boot and is also what > > > is set in the Pinebook Pro Device Tree, which is a device similar to the > > > PinePhone Pro but with a different form factor. > > > > > > Otherwise, the baud rate of the firmware and Linux don't match by default > > > and a 'console=ttyS2,1500000n8' kernel command line parameter is required > > > to have proper output for both. > > > > The interesting question is always if this will break someone else's setup. > > I've never really understood the strange setting of 1.5MBps, but on the > > other hand it _is_ a reality on most boards. > The 1.5M baud is default because the clock structure on rockchip > devices does not allow a clean 115200 baud. By attempting to force > 115200, it will always be slightly off (either low or high depending > on how the driver decided to round). If this actually causes any > problems is the subject of much debate. thanks so much for this piece of clock-detail. As I wrote, I never really understood the why _before_ but also never cared that much to dive into it and find out. So your explanation closes one knowledge gap in my head. Thanks a lot :-) Heiko
