Messages in this thread | | | Date | Fri, 08 May 2015 13:36:06 -0700 | From | santosh shilimkar <> | Subject | Re: [V3 PATCH 3/5] device property: Introduces device_dma_is_coherent() |
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On 5/8/2015 1:58 PM, Rafael J. Wysocki wrote: > On Friday, May 08, 2015 01:27:00 PM santosh shilimkar wrote: >> On 5/8/2015 1:49 PM, Rafael J. Wysocki wrote: >>> On Thursday, May 07, 2015 09:12:00 PM santosh.shilimkar@oracle.com wrote: >>>> On 5/7/15 5:37 PM, Suravee Suthikulpanit wrote: >>>>> Currently, device drivers, which support both OF and ACPI, >>>>> need to call two separate APIs, of_dma_is_coherent() and >>>>> acpi_dma_is_coherent()) to determine device coherency attribute. >>>>> >>>>> This patch simplifies this process by introducing a new device >>>>> property API, device_dma_is_coherent(), which calls the appropriate >>>>> interface based on the booting architecture. >>>>> >>>>> Signed-off-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com> >>>>> --- >>>>> drivers/base/property.c | 12 ++++++++++++ >>>>> include/linux/property.h | 2 ++ >>>>> 2 files changed, 14 insertions(+) >>>>> >>>>> diff --git a/drivers/base/property.c b/drivers/base/property.c >>>>> index 1d0b116..8123c6e 100644 >>>>> --- a/drivers/base/property.c >>>>> +++ b/drivers/base/property.c >>>>> @@ -14,6 +14,7 @@ >>>>> #include <linux/export.h> >>>>> #include <linux/kernel.h> >>>>> #include <linux/of.h> >>>>> +#include <linux/of_address.h> >>>>> #include <linux/property.h> >>>>> >>>>> /** >>>>> @@ -519,3 +520,14 @@ unsigned int device_get_child_node_count(struct device *dev) >>>>> return count; >>>>> } >>>>> EXPORT_SYMBOL_GPL(device_get_child_node_count); >>>>> + >>>>> +bool device_dma_is_coherent(struct device *dev) >>>>> +{ >>>>> + if (IS_ENABLED(CONFIG_OF) && dev->of_node) >>>> >>>> Do you really need that IS_ENABLED(CONFIG_OF) ? >>>> In other words, dev->of_node should be null for !CONFIG_OF >>> >>> Yes, but IS_ENABLED(CONFIG_OF) causes the check to be optimized away by the >>> compiler if CONFIG_OF is not enabled. >>> >> Sure but my point was why you need it when just 'dev->of_node' check >> is enough. May be I missed something. > > dev->of_node is present when CONFIG_OF is not enabled too. Without the > IS_ENABLED(CONFIG_OF) this becomes a pointless pointer check that will > always evaluate to 'false' on systems without CONFIG_OF, AFAICS. > Got it now. Thanks for expanding it.
Regards, Santosh
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