lkml.org 
[lkml]   [2015]   [Feb]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] dmaengine: dw: support for clockless platforms
From
Date
On Wed, 2015-02-11 at 10:10 +0800, Viresh Kumar wrote:
> On Tue, Jan 20, 2015 at 8:57 PM, Heikki Krogerus
> <heikki.krogerus@linux.intel.com> wrote:
> > When requesting clock in the platform driver, leaving
> > chip->clk value as NULL if -ENOENT is returned, and
> > continue. With other errors returning failure. It makes the
> > driver usable on platforms that do not provide the clock.
> >
> > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > ---
> > drivers/dma/dw/platform.c | 8 ++++++--
> > 1 file changed, 6 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/dma/dw/platform.c b/drivers/dma/dw/platform.c
> > index 32ea1ac..b183bc0 100644
> > --- a/drivers/dma/dw/platform.c
> > +++ b/drivers/dma/dw/platform.c
> > @@ -180,8 +180,12 @@ static int dw_probe(struct platform_device *pdev)
> > chip->dev = dev;
> >
> > chip->clk = devm_clk_get(chip->dev, "hclk");
> > - if (IS_ERR(chip->clk))
> > - return PTR_ERR(chip->clk);
> > + if (IS_ERR(chip->clk)) {
> > + if (PTR_ERR(chip->clk) == -ENOENT)
> > + chip->clk = NULL;
>
> This is wrong and reasons are mentioned in this thread:
>
> http://lists.infradead.org/pipermail/linux-arm-kernel/2012-March/088437.html

Thanks for the link.

>
> You don't need to set it to NULL, if CONFIG_HAVE_CLK isn't set
> the dummy routines would take care of it.

Yeah, but in our case we have CONFIG_HAVE_CLK=y and no clk is provided
since IP is clockless. What could you suggest to do in such case?

--
Andy Shevchenko <andriy.shevchenko@intel.com>
Intel Finland Oy



\
 
 \ /
  Last update: 2015-02-11 13:21    [W:0.076 / U:3.984 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site