On Fri, 26 Oct 2012 14:57:31 -0700
Min Zhang wrote:
> On Fri, Oct 26, 2012 at 7:19 AM, Alan Cox wrote:
>
> > So we only need to check this in serial8250_handle_irq when IIR indicates
> > a data timeout interrupt ?
> >
> > Can we do
> >
> > if ((iir & 0x0F) == 0x0C) {
> >
On Fri, Oct 26, 2012 at 7:19 AM, Alan Cox wrote:
> So we only need to check this in serial8250_handle_irq when IIR indicates
> a data timeout interrupt ?
>
> Can we do
>
> if ((iir & 0x0F) == 0x0C) {
> /* Expensive RDI check */
> }
>
>
>
> Alan
Checking data timeo
> It is racing. For "too much work for irq", here is sequence events
> analyzed by a Motorola engineer:
Thanks - this is enormously helpful in understanding the report.
> 5) The LSR indicates that the transmitter needs data,
> but also indicates the presence of data in the FIFO (0x61 in t
On Tue, Oct 23, 2012 at 3:01 AM, Alan Cox wrote:
>
> > Added module parameter skip_rdi_check to opt out this workaround.
>
> NAK. Anything like this should be runtime.
One can echo 1 (or 0) > /sys/modules/8250/parameters/skip_rdi_check
during run time to turn it off (or on) dynamically. Does it c
> Added module parameter skip_rdi_check to opt out this workaround.
NAK. Anything like this should be runtime.
> Tested on Radisys ATCA 46XX which uses FPGA 16550-compatible and
> other generic 16550 UART. It takes from an hour to days to reproduce by
> pumping inputs to serial console continousl
The patch works around two UART interrupt bugs when the serial console is
flooded with inputs:
1. syslog shows "serial8250: too much works for irq"
2. serial console stops responding to key stroke
serial8250_handle_irq() checks UART_IIR_RDI before reading receive fifo
and clears bogus interrupt
6 matches
Mail list logo
