From mboxrd@z Thu Jan 1 00:00:00 1970 From: linux@arm.linux.org.uk (Russell King - ARM Linux) Date: Tue, 7 Jan 2014 01:11:21 +0000 Subject: Regression (ARM) arch/arm/mm/init.c doesn't build without CONFIG_ARM_PATCH_PHYS_VIRT. In-Reply-To: <52CB3F55.1050404@ti.com> References: <20140106223906.GH27432@n2100.arm.linux.org.uk> <52CB3F55.1050404@ti.com> Message-ID: <20140107011121.GI27432@n2100.arm.linux.org.uk> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Jan 06, 2014 at 06:42:13PM -0500, Santosh Shilimkar wrote: > On Monday 06 January 2014 05:39 PM, Russell King - ARM Linux wrote: > > On Mon, Jan 06, 2014 at 08:28:20PM +0100, Krzysztof Ha?asa wrote: > >> Russell, Santosh, > >> > >> the unneeded commit causing regression is still in place. Please try to > >> compile an ARM kernel without CONFIG_ARM_PATCH_PHYS_VIRT and with > >> CONFIG_ZONE_DMA and see for yourself, if you don't believe me. > >> > >> Please be aware that this commit fixes nothing, its only function is > >> causing the regression - so we don't lose anything by reverting it. > >> > >> If the attached wasn't clear, what the defective commit presently does > >> is changing a perfectly valid code into a code referencing a variable > >> which (without CONFIG_ARM_PATCH_PHYS_VIRT set) doesn't at all exist. > >> > >> With CONFIG_ARM_PATCH_PHYS_VIRT set, this commit does precisely nothing. > > /-------------------------------------------------------------- | > > Right, so, with Assabet, which has CONFIG_DMA_ZONE=y and | > > CONFIG_ARM_PATCH_PHYS_VIRT=y: | > > | > > $ make O=../build/assabet arch/arm/mm/init.i | > > | > > gives: | > > arm_dma_limit = __pv_phys_offset + arm_dma_zone_size - 1; | > > | > > with or without Santosh's patch. \-------------------------------------------------------------- > May be I missed your point but I ended up creating the patch because > the CMA reservation was failing on Keystone since the arm_dma_limit > wasn't right since it wasn't considering the actual __pv_phys_offset. > > Isn't that an issue ? See the above. Your patch has _no_ effect what so ever when CONFIG_ARM_PATCH_PHYS_VIRT=y - which you have on the Keystone, right? If you don't believe me, ask make to produce arch/arm/mm/init.i, which is the output from the preprocessor, comparing the resulting generated file both with and without your patch applied. -- FTTC broadband for 0.8mile line: 5.8Mbps down 500kbps up. Estimation in database were 13.1 to 19Mbit for a good line, about 7.5+ for a bad. Estimate before purchase was "up to 13.2Mbit".