On 25. 10. 24, 12:57, 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. 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>
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@@ -1562,12 +1566,20 @@ static inline void __start_tx(struct uart_port *port) * stoppable by disabling the UART_IER_RDI interrupt. (Some chips set the * UART_LSR_DR bit even when UART_IER_RDI is disabled, foiling this approach.) */ -void serial8250_em485_start_tx(struct uart_8250_port *up) +void serial8250_em485_start_tx(struct uart_8250_port *up, bool in_con) { unsigned char mcr = serial8250_in_MCR(up);- if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX))- serial8250_stop_rx(&up->port); + if (!(up->port.rs485.flags & SER_RS485_RX_DURING_TX)) { + /* + * In console context, caller handles interrupt disabling. So + * only LSR_DR masking is needed. + */ + if (in_con) + __serial8250_stop_rx_mask_dr(&up->port); + else + serial8250_stop_rx(&up->port);
Would it make sense to propagate in_con into serial8250_stop_rx() and do the logic there? That would effectively eliminate patch 2/6.
thanks, -- js suse labs
