Good morning, I'm encountering reliability issues with DDC/CI communication when using USB-C connection. Initially using ddc-hi (which uses this package), I ran into several issues that I've partially resolved but still need help addressing.
Environment
OS: macOS Display Connection: USB-C
for _ in 1 ... (numOfRetryAttemps ?? 4) + 1 {
for _ in 1 ... max((numOfWriteCycles ?? 2) + 0, 1) {
usleep(writeSleepTime ?? 10000)
success = IOAVServiceWriteI2C(service, UInt32(ARM64_DDC_7BIT_ADDRESS), UInt32(dataAddress), &packet, UInt32(packet.count)) == 0
}
if !reply.isEmpty {
usleep(readSleepTime ?? 50000)
if IOAVServiceReadI2C(service, UInt32(ARM64_DDC_7BIT_ADDRESS), 0, &reply, UInt32(reply.count)) == 0 {
success = self.checksum(chk: 0x50, data: &reply, start: 0, end: reply.count - 2) == reply[reply.count - 1]
}
}
if success {
return success
}
usleep(retrySleepTime ?? 20000)
}
The result from IOAVServiceReadI2C is not reliable in some cases.
Do we have any other API to get VCP code from monitor like Intel version done.
The previous APIs weren’t working anymore on the M1 GPU, the IOFramebuffer was now an IOMobileFramebuffer and the IOI2C* functions weren’t doing anything.