Re: [PATCH 1/1] mct_u232: added _ioctl, _msr_to_icount and _get_icount functions

[Tsozik <tsozik@yahoo.com>]

Pete,

Many thanks for your reply again. I actually still own an antique HP a230n (disclaimer: I got it from/with my wife and would never buy it myself). According to dmesg it's got built-in 8250-compliant serial:

[vtsozik@f15 serial]$  dmesg | grep -i serial | grep 8250
Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
serial8250: ttyS0 at I/O 0x3f8 (irq = 4) is a 16550A
[vtsozik@f15 serial]$

So I ran geiger counter against /dev/ttyS0 device for 20 minutes and acquired 20 measurements. Then I compared last average with last 20 minute measurement average acquired via mct_u232 on the laptop placed nearby. The error was ~4% (rounded up). Taking in consideration that measurements were not acquired synchronously (i.e. in 2 different time slots) this is a pretty good match. 

Thank you again,
 Vadim.

--- On Mon, 12/27/10, Pete Zaitcev <zaitcev@redhat.com> wrote:

> From: Pete Zaitcev <zaitcev@redhat.com>
> Subject: Re: [PATCH 1/1] mct_u232: added _ioctl, _msr_to_icount and _get_icount functions
> To: "Tsozik" <tsozik@yahoo.com>
> Cc: "Greg Kroah-Hartman" <gregkh@suse.de>, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, zaitcev@redhat.com
> Date: Monday, December 27, 2010, 5:12 PM
> On Mon, 27 Dec 2010 12:55:38 -0800
> (PST)
> Tsozik <tsozik@yahoo.com>
> wrote:
> 
> > +static void mct_u232_msr_to_icount(struct
> async_icount *icount,
> > +       
>            
>     unsigned char msr)
> > +{
> > +    /* Translate Control Line states
> */
> > +    if (msr & MCT_U232_MSR_DDSR)
> > +       
> icount->dsr++;
> > +    if (msr & MCT_U232_MSR_DCTS)
> > +       
> icount->cts++;
> > +    if (msr & MCT_U232_MSR_DRI)
> > +       
> icount->rng++;
> > +    if (msr & MCT_U232_MSR_DCD)
> > +       
> icount->dcd++;
> > +} /* mct_u232_msr_to_icount */
> 
> This looks good to me, but since it's a new hardware
> facility that
> we did not use previously, I'd like to make sure this works
> for you.
> 
> > mct_u232_msr_to_icount uses delta nibble to track
> state changes.
> > RM-60 testing showed the same levels as measured by
> PDM-2 in close
> > proximity to RM-60.
> 
> Right, this is good. I have just one request for you: could
> you find
> somewhere a computer with a built-in 8250-compatible serial
> port,
> attach RM-60 to it, and run your counting application
> there?
> I think your patch looks just fine, but I would like to
> make sure
> that we (e.g. mct_u232+patch) are truly compatible now.
> 
> -- Pete
>