On Wed, Apr 25, 2012 at 1:48 AM, Russell King - ARM Linux <linux@xxxxxxxxxxxxxxxx> wrote: > Look, it's very very simple. Thanks for explaining. > Finally, if a platform has clk API support enabled, and a driver requests > a clock, and clk_get() returns an error, it means the clock was not found. > That's a fatal error for the driver, because it means that something is > wrong in the lookup tables - moreover, it means that _potentially_ someone > screwed up the clk matching and this device has a clock which needs some > control, but wasn't found. I don't think ignoring that kind of error, > even by printing a warning, is a particularly good approach - it seems > to me it makes things fragile. What if this missing clock causes the > bus to your device to ultimately hang? 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. -- viresh -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
