From 9ab57658a608f879469ffa22b723c4539c05a58f Mon Sep 17 00:00:00 2001 From: Sean Paul Date: Tue, 18 Aug 2020 11:38:49 -0400 Subject: drm/i915: Fix sha_text population code This patch fixes a few bugs: 1- We weren't taking into account sha_leftovers when adding multiple ksvs to sha_text. As such, we were or'ing the end of ksv[j - 1] with the beginning of ksv[j] 2- In the sha_leftovers == 2 and sha_leftovers == 3 case, bstatus was being placed on the wrong half of sha_text, overlapping the leftover ksv value 3- In the sha_leftovers == 2 case, we need to manually terminate the byte stream with 0x80 since the hardware doesn't have enough room to add it after writing M0 The upside is that all of the HDCP supported HDMI repeaters I could find on Amazon just strip HDCP anyways, so it turns out to be _really_ hard to hit any of these cases without an MST hub, which is not (yet) supported. Oh, and the sha_leftovers == 1 case works perfectly! Fixes: ee5e5e7a5e0f ("drm/i915: Add HDCP framework + base implementation") Cc: Chris Wilson Cc: Ramalingam C Cc: Daniel Vetter Cc: Sean Paul Cc: Jani Nikula Cc: Joonas Lahtinen Cc: Rodrigo Vivi Cc: intel-gfx@lists.freedesktop.org Cc: # v4.17+ Reviewed-by: Ramalingam C Signed-off-by: Sean Paul Signed-off-by: Ramalingam C Link: https://patchwork.freedesktop.org/patch/msgid/20200818153910.27894-2-sean@poorly.run (cherry picked from commit 1f0882214fd0037b74f245d9be75c31516fed040) Signed-off-by: Jani Nikula --- include/drm/drm_hdcp.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include') diff --git a/include/drm/drm_hdcp.h b/include/drm/drm_hdcp.h index c6bab4986a65..fe58dbb46962 100644 --- a/include/drm/drm_hdcp.h +++ b/include/drm/drm_hdcp.h @@ -29,6 +29,9 @@ /* Slave address for the HDCP registers in the receiver */ #define DRM_HDCP_DDC_ADDR 0x3A +/* Value to use at the end of the SHA-1 bytestream used for repeaters */ +#define DRM_HDCP_SHA1_TERMINATOR 0x80 + /* HDCP register offsets for HDMI/DVI devices */ #define DRM_HDCP_DDC_BKSV 0x00 #define DRM_HDCP_DDC_RI_PRIME 0x08 -- cgit v1.2.3-59-g8ed1b