* Need to disable MSR interrupts in 8250 driver. Request for guidance...
@ 2011-01-03 14:15 Michael Williamson
2011-01-03 23:56 ` Kevin Hilman
0 siblings, 1 reply; 3+ messages in thread
From: Michael Williamson @ 2011-01-03 14:15 UTC (permalink / raw)
To: linux-serial; +Cc: davinci-linux-open-source
Hello,
I am working on platform from the davinci architecture that uses the 8520 UART
driver. However, there are some configurations that do not have a valid
CTS input pin (it is a multi-purpose pin on a SoC part, and it may be configured
for other functions). These configurations can cause a pile of "false"
MSR interrupts. If, in 8250.c, I set the UART_BUG_NOMSR flag as part of
the up->bugs information, the problem clears up.
The problem is that there is no way to pass bugs information via platform data.
The link (below) contains a work-around patch that I had submitted to the davinci
group. It was suggested that I get guidance from the folks on the davinci-serial
list, and that I should consider figuring out a way to set the UART_BUG_NOMSR
flag from the platform or initialization data. The patch submission also has a
more detailed description of the problem for anyone interested.
https://patchwork.kernel.org/patch/442671/
Should I create a new port type, add a new UPF_ flag in the flags field, figure
out how to pass bugs information via platform data, or continue along the
work-around path?
Thanks for any insight.
-Mike
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Need to disable MSR interrupts in 8250 driver. Request for guidance...
2011-01-03 14:15 Need to disable MSR interrupts in 8250 driver. Request for guidance Michael Williamson
@ 2011-01-03 23:56 ` Kevin Hilman
2011-01-04 0:07 ` Greg KH
0 siblings, 1 reply; 3+ messages in thread
From: Kevin Hilman @ 2011-01-03 23:56 UTC (permalink / raw)
To: Michael Williamson
Cc: linux-serial, davinci-linux-open-source, Greg Kroah-Hartman
Michael Williamson <michael.williamson@criticallink.com> writes:
> I am working on platform from the davinci architecture that uses the 8520 UART
> driver. However, there are some configurations that do not have a valid
> CTS input pin (it is a multi-purpose pin on a SoC part, and it may be configured
> for other functions). These configurations can cause a pile of "false"
> MSR interrupts. If, in 8250.c, I set the UART_BUG_NOMSR flag as part of
> the up->bugs information, the problem clears up.
[...]
> Should I create a new port type, add a new UPF_ flag in the flags field, figure
> out how to pass bugs information via platform data, or continue along the
> work-around path?
I added Greg KH to Cc as he's maintaining the 8250 core now.
IMO, adding UPF_ flag(s) to indicate this bug seems like the right way
to go to me.
Kevin
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: Need to disable MSR interrupts in 8250 driver. Request for guidance...
2011-01-03 23:56 ` Kevin Hilman
@ 2011-01-04 0:07 ` Greg KH
0 siblings, 0 replies; 3+ messages in thread
From: Greg KH @ 2011-01-04 0:07 UTC (permalink / raw)
To: Kevin Hilman; +Cc: Michael Williamson, linux-serial, davinci-linux-open-source
On Mon, Jan 03, 2011 at 03:56:45PM -0800, Kevin Hilman wrote:
> Michael Williamson <michael.williamson@criticallink.com> writes:
>
> > I am working on platform from the davinci architecture that uses the 8520 UART
> > driver. However, there are some configurations that do not have a valid
> > CTS input pin (it is a multi-purpose pin on a SoC part, and it may be configured
> > for other functions). These configurations can cause a pile of "false"
> > MSR interrupts. If, in 8250.c, I set the UART_BUG_NOMSR flag as part of
> > the up->bugs information, the problem clears up.
>
> [...]
>
> > Should I create a new port type, add a new UPF_ flag in the flags field, figure
> > out how to pass bugs information via platform data, or continue along the
> > work-around path?
>
> I added Greg KH to Cc as he's maintaining the 8250 core now.
>
> IMO, adding UPF_ flag(s) to indicate this bug seems like the right way
> to go to me.
Yes, it sounds correct to me as well.
thanks,
greg k-h
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2011-01-04 0:08 UTC | newest]
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2011-01-03 14:15 Need to disable MSR interrupts in 8250 driver. Request for guidance Michael Williamson
2011-01-03 23:56 ` Kevin Hilman
2011-01-04 0:07 ` Greg KH
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