On Wed, Jun 15, 2022 at 12:06:50PM +0300, Ilpo Järvinen wrote: > Accessing LSR requires port lock because it mutates lsr_saved_flags > in serial_lsr_in(). I got this as patch 2/3, where are the 1/3 and 3/3? ... > @@ -266,7 +266,10 @@ static int dw8250_handle_irq(struct uart_port *p) > > /* Manually stop the Rx DMA transfer when acting as flow controller */ > if (quirks & DW_UART_QUIRK_IS_DMA_FC && up->dma && up->dma->rx_running && rx_timeout) { > + spin_lock_irqsave(&p->lock, flags); > status = serial_lsr_in(up); > + spin_unlock_irqrestore(&p->lock, flags); This reminds me the question, why do we need to save flags here? Aren't we in IRQ context already? (Perhaps another patch might be issued.) -- With Best Regards, Andy Shevchenko