[bug report] serial: 8250: Extract IIR logic steering from rx dma

[bug report] serial: 8250: Extract IIR logic steering from rx dma

[Dan Carpenter]

Hello Peter Hurley,

The patch 33d9b8b23a73: "serial: 8250: Extract IIR logic steering
from rx dma" from Apr 9, 2016, leads to the following static checker
warning:

	drivers/tty/serial/8250/8250_omap.c:1093 handle_rx_dma()
	warn: signedness bug returning '(-22)'

drivers/tty/serial/8250/8250_omap.c
  1084  static bool handle_rx_dma(struct uart_8250_port *up, unsigned int iir)
               ^^^^
This returns bool

  1085  {
  1086          switch (iir & 0x3f) {
  1087          case UART_IIR_RLSI:
  1088          case UART_IIR_RX_TIMEOUT:
  1089          case UART_IIR_RDI:
  1090                  omap_8250_rx_dma_flush(up);
  1091                  return true;
  1092          }
  1093          return omap_8250_rx_dma(up);
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This returns error codes


  1094  }
  1095  
  1096  static unsigned char omap_8250_handle_rx_dma(struct uart_8250_port *up,
  1097                                               u8 iir, unsigned char status)
  1098  {
  1099          if ((status & (UART_LSR_DR | UART_LSR_BI)) &&
  1100              (iir & UART_IIR_RDI)) {
  1101                  if (handle_rx_dma(up, iir)) {
                            ^^^^^^^^^^^^^^^^^^^^^^
So I guess this is reversed for the omap_8250_rx_dma() case.

  1102                          status = serial8250_rx_chars(up, status);
  1103                          omap_8250_rx_dma(up);
  1104                  }
  1105          }
  1106  
  1107          return status;
  1108  }

regards,
dan carpenter