From mboxrd@z Thu Jan 1 00:00:00 1970 From: pankaj.dubey@samsung.com (pankaj.dubey) Date: Mon, 27 Feb 2017 08:47:18 +0530 Subject: [PATCH 2/2] media: s5p-mfc: fix MMAP of mfc buffer during reqbufs In-Reply-To: <81c11e69-b7eb-ccb5-a377-2848ec551274@osg.samsung.com> References: <1481888915-19624-1-git-send-email-pankaj.dubey@samsung.com> <1481888915-19624-3-git-send-email-pankaj.dubey@samsung.com> <81c11e69-b7eb-ccb5-a377-2848ec551274@osg.samsung.com> Message-ID: <384899ef-4e7e-d7f5-8f4f-ef2f023cb681@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hello Javier, On Saturday 25 February 2017 01:12 AM, Javier Martinez Canillas wrote: > Hello Pankaj, > > On 12/16/2016 08:48 AM, Pankaj Dubey wrote: >> From: Smitha T Murthy >> >> It has been observed on ARM64 based Exynos SoC, if IOMMU is not enabled >> and we try to use reserved memory for MFC, reqbufs fails with below >> mentioned error >> --------------------------------------------------------------------------- >> V4L2 Codec decoding example application >> Kamil Debski >> Copyright 2012 Samsung Electronics Co., Ltd. >> >> Opening MFC. >> (mfc.c:mfc_open:58): MFC Info (/dev/video0): driver="s5p-mfc" \ >> bus_info="platform:12c30000.mfc0" card="s5p-mfc-dec" fd=0x4[ >> 42.339165] Remapping memory failed, error: -6 >> >> MFC Open Success. >> (main.c:main:711): Successfully opened all necessary files and devices >> (mfc.c:mfc_dec_setup_output:103): Setup MFC decoding OUTPUT buffer \ >> size=4194304 (requested=4194304) >> (mfc.c:mfc_dec_setup_output:120): Number of MFC OUTPUT buffers is 2 \ >> (requested 2) >> >> [App] Out buf phy : 0x00000000, virt : 0xffffffff >> Output Length is = 0x300000 >> Error (mfc.c:mfc_dec_setup_output:145): Failed to MMAP MFC OUTPUT buffer >> ------------------------------------------------------------------------- >> This is because the device requesting for memory is mfc0.left not the parent mfc0. >> Hence setting of alloc_devs need to be done only if IOMMU is enabled >> and in that case both the left and right device is treated as mfc0 only. >> > > I see, so likely you were facing the issue described in patch 1/2 after this > patch since the driver doesn't set alloc_devs when IOMMU is disabled, right? > Yes. > In any case, I guess these patches have been superseded by Marek's series[0] > so they are no longer needed? > Yes, these patches have been superseded but now by Marek's series. I missed to check Marek's series [0] due to some official assignment, but we followed up our patch series with Marek, and fix was provided in of_reserved_mem.c via patch [1] which has been accepted and merged as well. I will try to find out some time and test Marek's patch series [0]. [1]: https://patchwork.kernel.org/patch/9482499/ Thanks, Pankaj Dubey > [0]: https://www.spinics.net/lists/linux-media/msg111156.html > > Best regards, >