On Fri 2024-10-25 13:03:26, John Ogness wrote: > For RS485 mode, if SER_RS485_RX_DURING_TX is not available, the > console write callback needs to enable/disable TX. It does this > by calling the rs485_start/stop_tx() callbacks. However, these > callbacks will disable/enable interrupts, which is a problem > for console write, as it must be responsible for > disabling/enabling interrupts. It is not clear to me what exactly is the problem. Is the main problem calling pm_runtime*() API because it uses extra locks and can cause deadlocks? Or is it more complicated? IMHO, it would deserve some explanation. > Add an argument @in_con to the rs485_start/stop_tx() callbacks > to specify if they are being called from console write. If so, > the callbacks will not handle interrupt disabling/enabling. > > For all call sites other than console write, there is no > functional change. > > Signed-off-by: John Ogness <john.ogness@xxxxxxxxxxxxx> It looks like the code does what the description says. And honestly, I do not have any idea how to improve the naming. I would keep it as is after reading John's answers in the thread. IMHO, one thing which makes things comlicated is that serial8250_em485_start_tx() and serial8250_em485_stop_tx() are not completely reversible operations. Especially, the change done by __serial8250_stop_rx_mask_dr() is not reverted in serial8250_em485_stop_tx(). It makes things look tricky. But I think that it is beyond the scope of this patchset to do anything about it. Just 2 my cents. Best Regaards, Petr
