Hi, > Am 09.05.2022 um 20:41 schrieb Zhou Yanjie <zhouyanjie@xxxxxxxxxxxxxx>: > > Hi Paul, > > On 2022/5/10 上午2:13, Paul Cercueil wrote: >> I can't say for sure that it's your problem, but your bluetooth nodes are missing "reg" properties. > > > Unfortunately it doesn't seem to be the problem here, I added "reg" and > the problem persists, and I've looked at other device trees that contain > "brcm,bcm43438-bt", none of them use "reg", and "reg" is not mentioned in > neither "Documentation/devicetree/bindings/serial/nxp,sc16is7xx.txt" nor > "Documentation/devicetree/bindings/net/broadcom-bluetooth.yaml". what happens if you remove the serdev children from DTS? Does the driver create two separate /dev/tty ports? And do they work? Maybe the sc16is752 driver does not separate them for child nodes, i.e. while "reg" should be added it may not be handled? BR, Nikolaus