On Thu, Sep 22, 2022 at 05:43:53PM +0200, Lukas Wunner wrote: > On Thu, Sep 22, 2022 at 04:43:51PM +0200, Greg Kroah-Hartman wrote: > > On Wed, Sep 21, 2022 at 06:39:33AM +0200, Lukas Wunner wrote: > > > When a UART port is newly registered, uart_configure_port() seeks to > > > deassert RS485 Transmit Enable by setting the RTS bit in port->mctrl. > > > However a number of UART drivers interpret a set RTS bit as *assertion* > > > instead of deassertion: Affected drivers include those using > > > serial8250_em485_config() (except 8250_bcm2835aux.c) and some using > > > mctrl_gpio (e.g. imx.c). > > > > > > Since the interpretation of the RTS bit is driver-specific, it is not > > > suitable as a means to centrally deassert Transmit Enable in the serial > > > core. Instead, the serial core must call on drivers to deassert it in > > > their driver-specific way. One way to achieve that is to call > > > ->rs485_config(). It implicitly deasserts Transmit Enable. > > > > > > So amend uart_configure_port() and uart_resume_port() to invoke > > > uart_rs485_config(). That allows removing calls to uart_rs485_config() > > > from drivers' ->probe() hooks and declaring the function static. > [...] > > > > This message never made it to lore.kernel.org, so I can't seem to apply > > it using `b4`. > > > > Can you resend it so that it does make it to the public archives? > > Yes, both v1 and v2 didn't make it to the mailing list archive. > My suspicion is that the Cc: line was probably too long. > > I resent as v3 with only you in To: and the mailing list in Cc: and > this time it went through: > > https://lore.kernel.org/linux-serial/2de36eba3fbe11278d5002e4e501afe0ceaca039.1663860626.git.lukas@xxxxxxxxx/ > > On the bright side, v2 contained an embarrassing checkpatch issue > (superfluous newline) and resending as v3 provided a welcome > opportunity to fix that. :) v3 did not have a changelog :( v4?
