lkml.org 
[lkml]   [2018]   [Feb]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] clk: don't call __of_clk_get_by_name() unnecessarily from clk_get()
On Mon, Feb 12, 2018 at 02:51:57PM -0600, David Lechner wrote:
> On 02/12/2018 08:24 AM, Bartosz Golaszewski wrote:
> >From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> >
> >The way this function is implemented caused some confusion when
> >converting the TI DaVinci platform to using the common clock framework.
> >
> >Current kernel supports booting DaVinci boards both in device tree as
> >well as legacy, board-file mode. In the latter, we always end up
> >calling clk_get_sys() as of_node is NULL and __of_clk_get_by_name()
> >returns -ENOENT.
> >
> >It was not obvious at first glance how clk_get(dev, NULL) will work in
> >board-file mode since we always call __of_clk_get_by_name(). Let's make
> >it clearer by checking if of_node is NULL and skipping right to
> >clk_get_sys().
> >
> >Cc: Sekhar Nori <nsekhar@ti.com>
> >Cc: Kevin Hilman <khilman@baylibre.com>
> >Cc: David Lechner <david@lechnology.com>
> >Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
> >---
> > drivers/clk/clkdev.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> >diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
> >index 7513411140b6..f394e8964909 100644
> >--- a/drivers/clk/clkdev.c
> >+++ b/drivers/clk/clkdev.c
> >@@ -199,7 +199,7 @@ struct clk *clk_get(struct device *dev, const char *con_id)
> > const char *dev_id = dev ? dev_name(dev) : NULL;
> > struct clk *clk;
> >- if (dev) {
> >+ if (dev && dev->of_node) {
> > clk = __of_clk_get_by_name(dev->of_node, dev_id, con_id);
> > if (!IS_ERR(clk) || PTR_ERR(clk) == -EPROBE_DEFER)
> > return clk;
> >
>
> Shouldn't you be sending this to the linux-clk mailing list and cc'ing
> the clock maintainers?

No, I'm the maintainer for clkdev, as per MAINTAINERS.

> FWIW, it seems pretty clear to me that if we are using a board file
> then we should expect clk_get_sys() to be called because there is
> no device tree.

clk_get() pre-dates DT, and using it has no bearing on whether DT is
in use or not. The above change looks correct to me - if the
struct device is not a DT device, then we shouldn't be trying to look
up the clock in DT.

--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up
According to speedtest.net: 8.21Mbps down 510kbps up

\
 
 \ /
  Last update: 2018-02-12 22:01    [W:0.058 / U:0.088 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site