Re: saa7134 and μPD61151 MPEG2 coder

[Hans Verkuil <hverkuil@xs4all.nl>]

On Thursday 28 January 2010 03:09:41 Dmitri Belimov wrote:
> HIi Hans
> 
> > Hi Dmitri,
> > 
> > Just a quick note: the video4linux mailinglist is obsolete, just use
> > linux-media.
> 
> OK
> 
> > On Wednesday 27 January 2010 06:36:37 Dmitri Belimov wrote:
> > > Hi Hans.
> > > 
> > > I finished saa7134 part of SPI. Please review saa7134-spi.c and
> > > diff saa7134-core and etc. I wrote config of SPI to board
> > > structure. Use this config for register master and slave devices.
> > > 
> > > SPI other then I2C, do not need call request_module. Udev do it. 
> > > I spend 10 days for understanding :(  
> > 
> > I'm almost certain that spi works the same way as i2c and that means
> > that you must call request_module. Yes, udev will load it for you,
> > but that is a delayed load: i.e. the module may not be loaded when we
> > need it. The idea behind this is that usually i2c or spi modules are
> > standalone, but in the context of v4l such modules are required to be
> > present before the bridge can properly configure itself.
> > 
> > The easiest way to ensure the correct load sequence is to do a
> > request_module at the start.
> > 
> > Now, I haven't compiled this, but I think this will work:
> > 
> > struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev,
> >                struct spi_master *master, struct spi_board_info *info)
> > {
> > 	struct v4l2_subdev *sd = NULL;
> >         struct spi_device *spi;
> > 	
> > 	BUG_ON(!v4l2_dev);
> > 
> > 	if (module_name)
> >         	request_module(module_name);

There is one thing missing here: module_name should be passed in as argument
to v4l2_spi_new_subdev. Does this code actually compile? If so, then I suspect
module_name must be some global variable with some bogus value which causes
request_module to time out.

> [  240.476082]  [<f84c8f3b>] ? v4l2_spi_new_subdev_board+0x2e/0x35 [v4l2_common]
> [  240.476086]  [<f84c8fa6>] ? v4l2_spi_new_subdev+0x64/0x6c [v4l2_common]

Remove v4l2_spi_new_subdev_board. Just have a v4l2_spi_new_subdev as in my code.

Regards,

	Hans

-- 
Hans Verkuil - video4linux developer - sponsored by TANDBERG