On 09/08/2018 09:42 PM, Paul Kocialkowski wrote: > Hi, > > Le samedi 08 septembre 2018 à 13:24 +0200, Hans Verkuil a écrit : >> On 09/08/2018 12:22 PM, Chen-Yu Tsai wrote: >>> On Sat, Sep 8, 2018 at 6:06 PM Hans Verkuil <hverkuil@xxxxxxxxx> wrote: >>>> >>>> On 09/07/2018 06:33 PM, Paul Kocialkowski wrote: >>>>> This brings the requested modifications on top of version 9 of the >>>>> Cedrus VPU driver, that implements stateless video decoding using the >>>>> Request API. >>>>> >>>>> Paul Kocialkowski (2): >>>>> media: cedrus: Fix error reporting in request validation >>>>> media: cedrus: Add TODO file with tasks to complete before unstaging >>>>> >>>>> drivers/staging/media/sunxi/cedrus/TODO | 7 +++++++ >>>>> drivers/staging/media/sunxi/cedrus/cedrus.c | 15 ++++++++++++--- >>>>> 2 files changed, 19 insertions(+), 3 deletions(-) >>>>> create mode 100644 drivers/staging/media/sunxi/cedrus/TODO >>>>> >>>> >>>> So close... >>>> >>>> When compiling under e.g. intel I get errors since it doesn't know about >>>> the sunxi_sram_claim/release function and the PHYS_PFN_OFFSET define. >>>> >>>> Is it possible to add stub functions to linux/soc/sunxi/sunxi_sram.h >>>> if CONFIG_SUNXI_SRAM is not defined? That would be the best fix for that. >>>> >>>> The use of PHYS_PFN_OFFSET is weird: are you sure this is the right >>>> way? I see that drivers/of/device.c also sets dev->dma_pfn_offset, which >>>> makes me wonder if this information shouldn't come from the device tree. >>>> >>>> You are the only driver that uses this define directly, which makes me >>>> suspicious. >>> >>> On Allwinner platforms, some devices do DMA directly on the memory BUS >>> with the DRAM controller. In such cases, the DRAM has no offset. In all >>> other cases where the DMA goes through the common system bus and the DRAM >>> offset is either 0x40000000 or 0x20000000, depending on the SoC. Since the >>> former case is not described in the device tree (this is being worked on >>> by Maxime BTW), the dma_pfn_offset is not the value it should be. AFAIK >>> only the display and media subsystems (VPU, camera, TS) are wired this >>> way. >>> >>> In drivers/gpu/drm/sun4i/sun4i_backend.c (the display driver) we use >>> PHYS_OFFSET, which is pretty much the same thing. >>> >> >> OK, in that case just put #ifdef PHYS_PFN_OFFSET around that line together >> with a comment that this will eventually come from the device tree. > > That seems fine, although I'm less certain about what to do for the > SRAM situation. Other drivers that use SUNXI_SRAM have a Kconfig select > on it (that Cedrus lacks). Provided that the SRAM driver builds fine > for non-sunxi configs, bringing-in that select would remove the need > for dummy functions and also ensure that the actual implementation is > always used on sunxi. Otherwise, there'd be a risk of having the dummy > functions used (if the SRAM driver is not explicitly selected in the > config), causing a hang when accessing the VPU. You should certainly select this kernel config. But the real problem seems to to be drivers/soc/Makefile where it says: obj-$(CONFIG_ARCH_SUNXI) += sunxi/ I think this should be: obj-y += sunxi/ Now all compiles fine on i686 with the cedrus driver selecting SUNXI_SRAM. Regards, Hans
