From mboxrd@z Thu Jan 1 00:00:00 1970 From: k.kozlowski@samsung.com (Krzysztof Kozlowski) Date: Wed, 18 May 2016 17:01:22 +0200 Subject: [PATCH] ARM: samsung: improve static dma_mask definition In-Reply-To: <1463042333-281444-1-git-send-email-arnd@arndb.de> References: <1463042333-281444-1-git-send-email-arnd@arndb.de> Message-ID: <573C83C2.5090203@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 05/12/2016 10:38 AM, Arnd Bergmann wrote: > When no DMA master devices are part of the kernel configuration, > we get a warning about the unused dma mask definition: > > arch/arm/plat-samsung/devs.c:71:12: error: 'samsung_device_dma_mask' defined but not used [-Werror=unused-variable] > static u64 samsung_device_dma_mask = DMA_BIT_MASK(32); > > We could simply mark this as __maybe_unused to shut up that warning, > but a nicer solution seems to be to have a separate mask for each > device. The advantage is that a driver that happens to call > dma_set_mask() on one device doesn't implicitly change the mask > for the other devices as well. This is more of a theoretical > problem, as obviously nothing does it for the devices in this > file (or they would have always been broken), but it feels > cleaner that way. > > The definition works by creating an array in place so we can take > the address of it and let the compiler generate a hidden symbol > for it at compile time. > > Signed-off-by: Arnd Bergmann > --- > arch/arm/plat-samsung/devs.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Thanks, although does not look as critical fix but less warnings makes spotting right issues faster so applied for v4.7. Best regards, Krzysztof