[PATCH LINUX v3 00/10] tty: xuartps: Fix lock ups

Sören Brinkmann soren.brinkmann at xilinx.com
Sat Dec 5 14:02:36 PST 2015


On Sat, 2015-12-05 at 12:49PM -0500, Peter Hurley wrote:
> On 11/21/2015 09:59 PM, Soren Brinkmann wrote:
> > Hi,
> > 
> > here is v3 of this series. It's largely the same as before, but I
> > adjusted 'tty: xuartps: Don't consider circular buffer when enabling
> > transmitter' according to Peter's suggestions.
> 
> In reviewing this series, I thought the _OFFSET suffix for every register
> address to be excessive. I would refactor all that out; IOW,
> 
> -	isrstatus = readl(port->membase + CDNS_UART_ISR_OFFSET);
> +	isrstatus = readl(port->membase + CDNS_UART_ISR);

I'll add that as a patch on top of everything.

> 
> 
> > I also spent some time trying to get Peter's test for flow control and
> > xchar running. The xchar thing fails and will need some more work, but I
> > think in general it should be possible to get it to work.
> > The flow control test passes:
> > 
> > root at Xilinx-ZC1751-DC1:~# ./flow /dev/ttyPS0
> > Test flow control on /dev/ttyPS0
> > begin test1
> > patterns sent: 223  recvd: 208
> > read distribution: 1   = 0
> >                    2+  = 0
> >                    4+  = 0
> >                    8+  = 0
> >                   16+  = 0
> >                   32+  = 643
> >                   64+  = 0
> >                  128+  = 0
> >                  256+  = 0
> >                  512+  = 0
> > PASSED
> 
> This distribution looks like this exactly because the xchar test is
> failing. IOW, this driver isn't performing soft flow control (^S,^Q)
> like it should.

I tried to the your xchar test working, but so far that failed. I'll try
to spend some more time on this.

	Thanks,
	Sören



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