From mboxrd@z Thu Jan 1 00:00:00 1970 From: santosh.shilimkar@ti.com (Santosh Shilimkar) Date: Thu, 8 Aug 2013 10:19:54 -0400 Subject: [PATCHv3 4/9] ARM: OMAP2+: AM33XX: Reserve memory to comply with EMIF spec In-Reply-To: <1375811376-49985-5-git-send-email-d-gerlach@ti.com> References: <1375811376-49985-1-git-send-email-d-gerlach@ti.com> <1375811376-49985-5-git-send-email-d-gerlach@ti.com> Message-ID: <5203A90A.8090008@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tuesday 06 August 2013 01:49 PM, Dave Gerlach wrote: > From: Vaibhav Bedia > > SDRAM controller on AM33XX requires that a modification of certain > bit-fields in PWR_MGMT_CTRL register (ref. section 7.3.5.13 in > AM335x-Rev H) is followed by a dummy read access to SDRAM. This > scenario arises when entering a low power state like DeepSleep. > To ensure that the read is not from a cached region we reserve > some memory during bootup using the arm_memblock_steal() API. > > A subsequent patch will pass along the location of the reserved > memory location to the AM335x suspend handler which modifies the > PWR_MGMT_CTRL register in the EMIF. > > Signed-off-by: Vaibhav Bedia > Signed-off-by: Dave Gerlach > --- Acked-by: Santosh Shilimkar