From: Suravee Suthikulanit Subject: Re: [V4 PATCH 4/6] device property: Introduces device_dma_is_coherent() Date: Wed, 20 May 2015 16:32:45 -0500 Message-ID: <555CFD7D.5090208@amd.com> References: <1431724994-21601-1-git-send-email-Suravee.Suthikulpanit@amd.com> <1431724994-21601-5-git-send-email-Suravee.Suthikulpanit@amd.com> <20150520102829.GB11498@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit Cc: "rjw@rjwysocki.net" , "lenb@kernel.org" , Catalin Marinas , "bhelgaas@google.com" , "thomas.lendacky@amd.com" , "herbert@gondor.apana.org.au" , "davem@davemloft.net" , "arnd@arndb.de" , "msalter@redhat.com" , "hanjun.guo@linaro.org" , "al.stone@linaro.org" , "grant.likely@linaro.org" , "leo.duran@amd.com" , "linux-arm-kernel@lists.infradead.org" , "linux-acpi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linaro-acpi@lists.linaro.org" , "netdev@vger.kernel.org" To: Will Deacon Return-path: In-Reply-To: <20150520102829.GB11498@arm.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On 5/20/2015 5:28 AM, Will Deacon wrote: > On Fri, May 15, 2015 at 10:23:12PM +0100, 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 >> CC: Rafael J. Wysocki >> --- >> 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 >> #include >> #include >> +#include >> #include >> >> /** >> @@ -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) >> + return of_dma_is_coherent(dev->of_node); >> + else if (has_acpi_companion(dev)) >> + return acpi_dma_is_coherent(acpi_node(dev->fwnode)); > > I don't think you need the has_acpi_companion check, as acpi_node handles > this and acpi_dma_is_coherent(NULL) returns false. > > Will > You are right. Thanks, Suravee