mirror of
https://github.com/openwrt/openwrt.git
synced 2024-12-20 14:13:16 +00:00
77e97abf12
Also removes random module and switches to new bcm2711 thermal driver. Boot tested on RPi 4B v1.1 4G. Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
61 lines
2.2 KiB
Diff
61 lines
2.2 KiB
Diff
From 153f1e1def226f87cc4c307d2806b000a820f64b Mon Sep 17 00:00:00 2001
|
|
From: Gurchetan Singh <gurchetansingh@chromium.org>
|
|
Date: Tue, 17 Dec 2019 15:02:28 -0800
|
|
Subject: [PATCH] udmabuf: fix dma-buf cpu access
|
|
|
|
Commit 1ffe09590121fbb3786d6c860acdd200f7ab095c upstream.
|
|
|
|
I'm just going to put Chia's review comment here since it sums
|
|
the issue rather nicely:
|
|
|
|
"(1) Semantically, a dma-buf is in DMA domain. CPU access from the
|
|
importer must be surrounded by {begin,end}_cpu_access. This gives the
|
|
exporter a chance to move the buffer to the CPU domain temporarily.
|
|
|
|
(2) When the exporter itself has other means to do CPU access, it is
|
|
only reasonable for the exporter to move the buffer to the CPU domain
|
|
before access, and to the DMA domain after access. The exporter can
|
|
potentially reuse {begin,end}_cpu_access for that purpose.
|
|
|
|
Because of (1), udmabuf does need to implement the
|
|
{begin,end}_cpu_access hooks. But "begin" should mean
|
|
dma_sync_sg_for_cpu and "end" should mean dma_sync_sg_for_device.
|
|
|
|
Because of (2), if userspace wants to continuing accessing through the
|
|
memfd mapping, it should call udmabuf's {begin,end}_cpu_access to
|
|
avoid cache issues."
|
|
|
|
Reported-by: Chia-I Wu <olvaffe@gmail.com>
|
|
Suggested-by: Chia-I Wu <olvaffe@gmail.com>
|
|
Fixes: 284562e1f348 ("udmabuf: implement begin_cpu_access/end_cpu_access hooks")
|
|
Signed-off-by: Gurchetan Singh <gurchetansingh@chromium.org>
|
|
Link: http://patchwork.freedesktop.org/patch/msgid/20191217230228.453-1-gurchetansingh@chromium.org
|
|
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
|
|
---
|
|
drivers/dma-buf/udmabuf.c | 7 +++----
|
|
1 file changed, 3 insertions(+), 4 deletions(-)
|
|
|
|
--- a/drivers/dma-buf/udmabuf.c
|
|
+++ b/drivers/dma-buf/udmabuf.c
|
|
@@ -122,9 +122,8 @@ static int begin_cpu_udmabuf(struct dma_
|
|
if (IS_ERR(ubuf->sg))
|
|
return PTR_ERR(ubuf->sg);
|
|
} else {
|
|
- dma_sync_sg_for_device(dev, ubuf->sg->sgl,
|
|
- ubuf->sg->nents,
|
|
- direction);
|
|
+ dma_sync_sg_for_cpu(dev, ubuf->sg->sgl, ubuf->sg->nents,
|
|
+ direction);
|
|
}
|
|
|
|
return 0;
|
|
@@ -139,7 +138,7 @@ static int end_cpu_udmabuf(struct dma_bu
|
|
if (!ubuf->sg)
|
|
return -EINVAL;
|
|
|
|
- dma_sync_sg_for_cpu(dev, ubuf->sg->sgl, ubuf->sg->nents, direction);
|
|
+ dma_sync_sg_for_device(dev, ubuf->sg->sgl, ubuf->sg->nents, direction);
|
|
return 0;
|
|
}
|
|
|