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authorDamian Kos <dkos@cadence.com>2018-11-06 15:37:05 +0000
committerHeiko Stuebner <heiko@sntech.de>2018-11-19 14:59:50 +0100
commitfa68d4f8476bea4cdf441062b614b41bb85ef1da (patch)
tree092cca7931880e09cbdb9133d0574fd41558c744
parent21d808405fe49028036932dd969920f4fee4f481 (diff)
drm/rockchip: fix for mailbox read size
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
-rw-r--r--drivers/gpu/drm/rockchip/cdn-dp-reg.c2
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 3105965fc260..5a485489a1e2 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;