Re: [PATCH V3 07/12] ata/sata_mv: Remove conditional compilation ofclk code

From: Lothar WaÃmann
Date: Wed Apr 25 2012 - 02:44:27 EST


Hi,

Andrew Lunn writes:
> > This is what i was thinking too and thats why floated this version of patch.
> > But as Andrew said, clk API support is enabled for them, but still they
> > don't have a clk for sata. To get this working, there are two solutions:
> > - Create dummy clk for sata for that platform, so clk_get doesn't fail.
> > - Check for error before every call to clk APIs after clk_get().
> >
> > Andrew favored the second one. Which means, even on platforms
> > with clk API defined and clk enable required, if there are some issues
> > with lookup table, and clk_get() fails, system may hang when registers
> > are accessed. For this i favored first one.
>
> I'm not too sure how you are going to achieve 1)
>
> config SATA_MV
> tristate "Marvell SATA support"
> help
> This option enables support for the Marvell Serial ATA family.
> Currently supports 88SX[56]0[48][01] PCI(-X) chips,
> as well as the newer [67]042 PCI-X/PCIe and SOC devices.
>
> So this driver can be used with anything which has a PCI(-X) or PCIe
> bus, or Orion SoC and a few PowerPC SoCs.
>
> The SoCs are not too bad, we know which ones they are and we can add
> dummy entries to their device tree. However, how do you want to handle
> the PCI devices? Create the dummy entry somewhere in the middle of the
> PCI core?
>
> Thought not.
>
AFAICT the PCI archs do not have HAVE_CLK enabled. Thus they will have
a dummy clk API in place that provides the driver with a non-error
clk_get() return value.


Lothar WaÃmann
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