From mboxrd@z Thu Jan 1 00:00:00 1970 From: mathieu.poirier@linaro.org (Mathieu Poirier) Date: Thu, 30 Jun 2016 10:22:19 -0600 Subject: [PATCH 13/13] coresight: add PM runtime calls to coresight_simple_func() In-Reply-To: <1467303739-12543-1-git-send-email-mathieu.poirier@linaro.org> References: <1467303739-12543-1-git-send-email-mathieu.poirier@linaro.org> Message-ID: <1467303739-12543-14-git-send-email-mathieu.poirier@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org It is mandatory to enable a coresight block's power domain before trying to access management registers. Otherwise the transaction simply stalls, leading to a system hang. Signed-off-by: Mathieu Poirier Reviewed-by: Sudeep Holla --- drivers/hwtracing/coresight/coresight-priv.h | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h index ad975c58080d..decfd52b5dc3 100644 --- a/drivers/hwtracing/coresight/coresight-priv.h +++ b/drivers/hwtracing/coresight/coresight-priv.h @@ -16,6 +16,7 @@ #include #include #include +#include /* * Coresight management registers (0xf00-0xfcc) @@ -42,8 +43,11 @@ static ssize_t name##_show(struct device *_dev, \ struct device_attribute *attr, char *buf) \ { \ type *drvdata = dev_get_drvdata(_dev->parent); \ - return scnprintf(buf, PAGE_SIZE, "0x%x\n", \ - readl_relaxed(drvdata->base + offset)); \ + u32 val; \ + pm_runtime_get_sync(_dev->parent); \ + val = readl_relaxed(drvdata->base + offset); \ + pm_runtime_put_sync(_dev->parent); \ + return scnprintf(buf, PAGE_SIZE, "0x%x\n", val); \ } \ static DEVICE_ATTR_RO(name) -- 2.7.4