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| author | Damian Kos <dkos@cadence.com> | 2018-11-06 18:37:05 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-12 21:45:58 +0300 |
| commit | 96a4a6a7fe18da4ee64e6097cc38acd7fc3aa342 (patch) | |
| tree | a7c837b6f44dee4210d0665f5447a61fb42b60bb | |
| parent | e6a73f46ddfcecb404e5e2401c3da2c5ce9b3d76 (diff) | |
| download | linux-96a4a6a7fe18da4ee64e6097cc38acd7fc3aa342.tar.xz | |
drm/rockchip: fix for mailbox read size
[ Upstream commit fa68d4f8476bea4cdf441062b614b41bb85ef1da ]
Some of the functions (like cdn_dp_dpcd_read, cdn_dp_get_edid_block)
allow to read 64KiB, but the cdn_dp_mailbox_read_receive, that is
used by them, can read only up to 255 bytes at once. Normally, it's
not a big issue as DPCD or EDID reads won't (hopefully) exceed that
value.
The real issue here is the revocation list read during the HDCP
authentication process. (problematic use case:
https://chromium.googlesource.com/chromiumos/third_party/kernel/+/chromeos-4.4/drivers/gpu/drm/rockchip/cdn-dp-reg.c#1152)
The list can reach 127*5+4 bytes (num devs * 5 bytes per ID/Bksv +
4 bytes of an additional info).
In other words - CTSes with HDCP Repeater won't pass without this
fix. Oh, and the driver will most likely stop working (best case
scenario).
Signed-off-by: Damian Kos <dkos@cadence.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/1541518625-25984-1-git-send-email-dkos@cadence.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/gpu/drm/rockchip/cdn-dp-reg.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/gpu/drm/rockchip/cdn-dp-reg.c b/drivers/gpu/drm/rockchip/cdn-dp-reg.c index b14d211f6c21..0ed7e91471f6 100644 --- a/drivers/gpu/drm/rockchip/cdn-dp-reg.c +++ b/drivers/gpu/drm/rockchip/cdn-dp-reg.c @@ -147,7 +147,7 @@ static int cdn_dp_mailbox_validate_receive(struct cdn_dp_device *dp, } static int cdn_dp_mailbox_read_receive(struct cdn_dp_device *dp, - u8 *buff, u8 buff_size) + u8 *buff, u16 buff_size) { u32 i; int ret; |