To read pid/cid registers, the probed device need to be properly turned on. When it is inside a power domain, the bus code should ensure that the given power domain is enabled before trying to access device's registers.
Signed-off-by: Marek Szyprowski <m.szyprow...@samsung.com> Reviewed-by: Ulf Hansson <ulf.hans...@linaro.org> --- drivers/amba/bus.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index 643127f..570033b 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -60,6 +60,10 @@ static int amba_read_periphid(struct amba_device *dev) if (!tmp) return -ENOMEM; + ret = dev_pm_domain_attach(&dev->dev, true); + if (ret == -EPROBE_DEFER) + goto err_unmap; + ret = amba_get_enable_pclk(dev); if (ret == 0) { u32 pid, cid; @@ -84,6 +88,8 @@ static int amba_read_periphid(struct amba_device *dev) ret = -ENODEV; } + dev_pm_domain_detach(&dev->dev, true); +err_unmap: iounmap(tmp); return ret; -- 1.9.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/