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

From: SÃren Brinkmann
Date: Sat Dec 05 2015 - 17:02:56 EST


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@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,
SÃren
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