Messages in this thread | | | From | Laurent Pinchart <> | Subject | Re: Are media drivers abusing of GFP_DMA? - was: Re: [LSF/MM TOPIC NOTES] x86 ZONE_DMA love | Date | Mon, 07 May 2018 16:26:08 +0300 |
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Hi Mauro,
On Saturday, 5 May 2018 19:08:15 EEST Mauro Carvalho Chehab wrote: > There was a recent discussion about the use/abuse of GFP_DMA flag when > allocating memories at LSF/MM 2018 (see Luis notes enclosed). > > The idea seems to be to remove it, using CMA instead. Before doing that, > better to check if what we have on media is are valid use cases for it, or > if it is there just due to some misunderstanding (or because it was > copied from some other code). > > Hans de Goede sent us today a patch stopping abuse at gspca, and I'm > also posting today two other patches meant to stop abuse of it on USB > drivers. Still, there are 4 platform drivers using it: > > $ git grep -l -E "GFP_DMA\\b" drivers/media/ > drivers/media/platform/omap3isp/ispstat.c > drivers/media/platform/sti/bdisp/bdisp-hw.c > drivers/media/platform/sti/hva/hva-mem.c > drivers/media/spi/cxd2880-spi.c > > Could you please check if GFP_DMA is really needed there, or if it is > just because of some cut-and-paste from some other place?
I started looking at that for the omap3isp driver but Sakari beat me at submitting a patch. GFP_DMA isn't needed for omap3isp.
-- Regards,
Laurent Pinchart
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