Re: [PATCH 2/4] arch/arm/mach-at91/clock.c: Add missing IS_ERR test

From: Julia Lawall
Date: Tue Jan 25 2011 - 01:12:45 EST


On Tue, 25 Jan 2011, Jean-Christophe PLAGNIOL-VILLARD wrote:

> On 23:23 Mon 24 Jan , Russell King - ARM Linux wrote:
> > On Tue, Jan 25, 2011 at 10:51:38AM +1300, Ryan Mallon wrote:
> > > You could, but it would not be helpful. Clock associations are used so
> > > that _different_ devices can have the same function and map to the
> > > correct clock. This is used when there are multiple instances of a
> > > single peripheral. For example, the uart clocks work like this:
> > >
> > > at91_clock_associate("usart1_clk", &pdev->dev, "usart");
> > >
> > > so then you can do this in a driver:
> > >
> > > uart_clk = clk_get(&pdev->dev, "usart");
> > >
> > > Rather than:
> > >
> > > uart_clk = clk_get(NULL, "usart1_clk");
> > >
> > > The former will find the correct uart clock for the device. Because each
> > > uart is a separate device the correct clock will be selected for each uart.
> > >
> > > My point was that there should be no overlap between clk->name and
> > > clk->function otherwise clk_get will not be able to return the correct
> > > clock.
> >
> > It would be nice if AT91 could switch over to using clkdev at some
> > point, which greatly helps with associating struct clk's with their
> > device/function names - and reduces the amount of "different" code.
> I working on it that's was one of the reason I move clkdev to drivers
> as AT91 and AVR32 need to switch

Shall I just leave the patch as is then?

julia
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