From 7002786a12f64f80aefd083ab4807009a3a3dd13 Mon Sep 17 00:00:00 2001 From: Eric Anholt Date: Fri, 27 Jan 2017 13:55:01 -0800 Subject: [PATCH] staging: bcm2835-v4l2: Add a TODO file for improvements we need. Signed-off-by: Eric Anholt Signed-off-by: Greg Kroah-Hartman --- drivers/staging/media/platform/bcm2835/TODO | 39 +++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) create mode 100644 drivers/staging/media/platform/bcm2835/TODO diff --git a/drivers/staging/media/platform/bcm2835/TODO b/drivers/staging/media/platform/bcm2835/TODO new file mode 100644 index 0000000..61a5099 --- /dev/null +++ b/drivers/staging/media/platform/bcm2835/TODO @@ -0,0 +1,39 @@ +1) Support dma-buf memory management. + +In order to zero-copy import camera images into the 3D or display +pipelines, we need to export our buffers through dma-buf so that the +vc4 driver can import them. This may involve bringing in the VCSM +driver (which allows long-term management of regions of memory in the +space that the VPU reserved and Linux otherwise doesn't have access +to), or building some new protocol that allows VCSM-style management +of Linux's CMA memory. + +2) Avoid extra copies for padding of images. + +We expose V4L2_PIX_FMT_* formats that have a specified stride/height +padding in the V4L2 spec, but that padding doesn't match what the +hardware can do. If we exposed the native padding requirements +through the V4L2 "multiplanar" formats, the firmware would have one +less copy it needed to do. + +3) Port to ARM64 + +The bulk_receive() does some manual cache flushing that are 32-bit ARM +only, which we should convert to proper cross-platform APIs. + +4) Convert to be a platform driver. + +Right now when the module probes, it tries to initialize VCHI and +errors out if it wasn't ready yet. If bcm2835-v4l2 was built in, then +VCHI generally isn't ready because it depends on both the firmware and +mailbox drivers having already loaded. + +We should have VCHI create a platform device once it's initialized, +and have this driver bind to it, so that we automatically load the +v4l2 module after VCHI loads. + +5) Drop the gstreamer workaround. + +This was a temporary workaround for a bug that was fixed mid-2014, and +we should remove it before stabilizing the driver. + -- 2.7.4