Hi, Am Dienstag, 18. April 2023, 14:11:53 CEST schrieb Javier Martinez Canillas: > Heiko Stübner <heiko@xxxxxxxxx> writes: > > Hello Heiko, > > > 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 :-) > > Did you make a decision about this? I guess the clock explanation is yet > another argument in favour of switching the PPP to a 1.5 Mbps baud rate ? Sorry, but no decision made here. Either way it's breaking for someone, which makes this quite hard. The rate accuracy is the one side, the two-boot issue is the other side. And mainline u-boot (and levinboot - whatever that is) provides a 3rd side. People starting with the phone probably won't replace the bootloader in a first step but instead might play with a system image or newer kernel. So if the uart will break for everyone using the default bootloader from the factory that is somewhat bad. I don't have a Pinephone Pro myself, so I really hoped for some Acks or similar to appear in the meantime. Do we have someone with an actual Pine64 affiliation in this loop? Heiko
