On Tue, Jul 12, 2022 at 3:16 PM Vamshi Gajjela <vamshigajjela@xxxxxxxxxx> wrote: > > From: VAMSHI GAJJELA <vamshigajjela@xxxxxxxxxx> > > With PSLVERR_RESP_EN parameter set to 1, device generates an error the device > response when an attempt to read empty RBR with FIFO enabled. an empty > This happens when LCR writes are ignored when UART is busy. > dw8250_check_lcr() in retries to updateLCR, invokes dw8250_force_idle() > to clear and reset fifo and eventually reads UART_RX causing pslverr. fifo --> FIFO pslverr --> the error > Avoid this by not reading RBR/UART_RX when no data is available. ... > + unsigned int lsr; > struct uart_8250_port *up = up_to_u8250p(p); Can we keep it ordered according to the reversed xmas tree? ... > + /* > + * With PSLVERR_RESP_EN parameter set to 1, device generates pslverr the device pslverr --> an > + * error response when an attempt to read empty RBR with FIFO enabled Missed period. > + */ > + lsr = p->serial_in(p, UART_LSR); The only caller of this function already has the lsr value, why you can't (re)use it? > + if ((up->fcr & UART_FCR_ENABLE_FIFO) && !(lsr & UART_LSR_DR)) > + return; -- With Best Regards, Andy Shevchenko
