zaurus bluetooth regression

zaurus bluetooth regression

[Pavel Machek]

Hi!

It seems this commit

commit 7a56aa45982bb87bfca98a2832b5ae782c03364a
Author: Yegor Yefremov <yegor_sub1@visionsystems.de>
Date:   Wed Jun 16 16:29:55 2010 +0200

    serial: add UART_CAP_EFR and UART_CAP_SLEEP flags to 16C950 UARTs
definition

    Adding UART_CAP_EFR and UART_CAP_SLEEP flags will enable sleep
mode
    and automatic CTS flow control for 16C950 UARTs. It will also
avoid
    capabilities detection warning like this:

    "ttyS0: detected caps 00000700 should be 00000100"

    Signed-off-by: Yegor Yefremov <yegorslists@googlemail.com>
    Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

...is responsible for my bluetooth problems on zaurus -- at least
bisect pointed to it,  as I use 16C950-based bluetooth card, it seems
very logical. I'll try 2.6.37-rc8 with that patch reverted...

See https://bugzilla.kernel.org/show_bug.cgi?id=17061  .

								Pavel

diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
index 09ef570..bc8ed4b 100644
--- a/drivers/serial/8250.c
+++ b/drivers/serial/8250.c
@@ -241,7 +241,7 @@ static const struct serial8250_config uart_config[] = {
 		.fifo_size	= 128,
 		.tx_loadsz	= 128,
 		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
-		.flags		= UART_CAP_FIFO,
+		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
 	},
 	[PORT_16654] = {
 		.name		= "ST16654",

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

zaurus bluetooth regression

[Pavel Machek]

Hi!

> It seems this commit
> 
> commit 7a56aa45982bb87bfca98a2832b5ae782c03364a
...
> ...is responsible for my bluetooth problems on zaurus -- at least
> bisect pointed to it,  as I use 16C950-based bluetooth card, it seems
> very logical. I'll try 2.6.37-rc8 with that patch reverted...
> 

And yes, 37-rc8 with that reverted results in working bluetooth, so
yrs, that patch is responsible.

								Pavel

> diff --git a/drivers/serial/8250.c b/drivers/serial/8250.c
> index 09ef570..bc8ed4b 100644
> --- a/drivers/serial/8250.c
> +++ b/drivers/serial/8250.c
> @@ -241,7 +241,7 @@ static const struct serial8250_config uart_config[] = {
>  		.fifo_size	= 128,
>  		.tx_loadsz	= 128,
>  		.fcr		= UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10,
> -		.flags		= UART_CAP_FIFO,
> +		.flags		= UART_CAP_FIFO | UART_CAP_EFR | UART_CAP_SLEEP,
>  	},
>  	[PORT_16654] = {
>  		.name		= "ST16654",
> 

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

zaurus bluetooth regression

[Yegor Yefremov]

Hi Pavel,

>> It seems this commit
>>
>> commit 7a56aa45982bb87bfca98a2832b5ae782c03364a
> ...
>> ...is responsible for my bluetooth problems on zaurus -- at least
>> bisect pointed to it, ?as I use 16C950-based bluetooth card, it seems
>> very logical. I'll try 2.6.37-rc8 with that patch reverted...
>>
>
> And yes, 37-rc8 with that reverted results in working bluetooth, so
> yrs, that patch is responsible.

could you tell, what kind of problem you're encountering and if you
could tell, which flag UART_CAP_EFR or UART_CAP_SLEEP causes the
problem?

Yegor

zaurus bluetooth regression

[Pavel Machek]

Hi!

> >> It seems this commit
> >>
> >> commit 7a56aa45982bb87bfca98a2832b5ae782c03364a
> > ...
> >> ...is responsible for my bluetooth problems on zaurus -- at least
> >> bisect pointed to it, ?as I use 16C950-based bluetooth card, it seems
> >> very logical. I'll try 2.6.37-rc8 with that patch reverted...
> >>
> >
> > And yes, 37-rc8 with that reverted results in working bluetooth, so
> > yrs, that patch is responsible.
> 
> could you tell, what kind of problem you're encountering and if you
> could tell, which flag UART_CAP_EFR or UART_CAP_SLEEP causes the
> problem?

Bluetooth will not work with 'tx command timeout', details should be
in bugzilla.

CAP_EFR seems to cause the problem.
								Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

zaurus bluetooth regression

[Yegor Yefremov]

>> >> It seems this commit
>> >>
>> >> commit 7a56aa45982bb87bfca98a2832b5ae782c03364a
>> > ...
>> >> ...is responsible for my bluetooth problems on zaurus -- at least
>> >> bisect pointed to it, ?as I use 16C950-based bluetooth card, it seems
>> >> very logical. I'll try 2.6.37-rc8 with that patch reverted...
>> >>
>> >
>> > And yes, 37-rc8 with that reverted results in working bluetooth, so
>> > yrs, that patch is responsible.
>>
>> could you tell, what kind of problem you're encountering and if you
>> could tell, which flag UART_CAP_EFR or UART_CAP_SLEEP causes the
>> problem?
>
> Bluetooth will not work with 'tx command timeout', details should be
> in bugzilla.
>
> CAP_EFR seems to cause the problem.

Aside from sleep functions the only impact CAP_EFR makes is enabling
automatic CTS flow control. Below the cite from 16C950 data sheet:

"EFR[7]: Enable automatic CTS flow control.
logic 0 ?   CTS flow control is disabled (default).
logic 1 ?   CTS flow control is enabled in Enhanced mode
(i.e. EFR[4] = 1), where the data transmission is
prevented  whenever  the  CTS#  pin  is  held
inactive high. 650 and 950-mode drivers should
use  this  bit  to  enable  CTS  flow  control.    750
mode drivers should use MCR[5].

When automatic CTS flow control is enabled and the CTS#
input becomes active, the UART will disable transmission
as soon as any current character transmission is complete.
Transmission   is   resumed   whenever   the   CTS#   input
becomes inactive. "

I've tested with such an UART and transmitted some chunk of data with
and without RTS/CTS flow control enabled at 460800 b/s. The test
showed that in enabled state all data was transmitted correctly.
Without RTS/CTS flow control enabled there was massive data loss, as
expected. So the flow control function seems to work correctly.

Regards,
Yegor