Re: [PATCH v10 10/40] drm: helper functions for hdcp2 seq_num to from u32

Shankar, Uma
2019-02-04T14:20:41Z

>-----Original Message-----
>From: C, Ramalingam
>Sent: Thursday, January 31, 2019 12:29 PM
>To: intel-gfx@lists.freedesktop.org; dri-devel@lists.freedesktop.org;
>daniel.vetter@ffwll.ch; Winkler, Tomas <tomas.winkler@intel.com>; Shankar,
>Uma <uma.shankar@intel.com>
>Cc: C, Ramalingam <ramalingam.c@intel.com>
>Subject: [PATCH v10 10/40] drm: helper functions for hdcp2 seq_num to from u32
>
>Library functions for endianness are aligned for 16/32/64 bits.
>But hdcp sequence numbers are 24bits(big endian).
>So for their conversion to and from u32 helper functions are developed.
>
>v2:
> Comment is updated. [Daniel]
>
>Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
>Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Looks ok to me.
Reviewed-by: Uma Shankar <uma.shankar@intel.com>

>---
> include/drm/drm_hdcp.h | 18 ++++++++++++++++++
> 1 file changed, 18 insertions(+)
>
>diff --git a/include/drm/drm_hdcp.h b/include/drm/drm_hdcp.h index
>d6dfef8cff6a..7260b31af276 100644
>--- a/include/drm/drm_hdcp.h
>+++ b/include/drm/drm_hdcp.h
>@@ -252,4 +252,22 @@ struct hdcp2_dp_errata_stream_type {
> #define HDCP_2_2_HDMI_RXSTATUS_READY(x) ((x) & BIT(2))
> #define HDCP_2_2_HDMI_RXSTATUS_REAUTH_REQ(x) ((x) & BIT(3))
>
>+/*
>+ * Helper functions to convert 24bit big endian hdcp sequence number to
>+ * host format and back
>+ */
>+static inline
>+u32 drm_hdcp2_seq_num_to_u32(u8 seq_num[HDCP_2_2_SEQ_NUM_LEN]) {
>+ return (u32)(seq_num[2] | seq_num[1] << 8 | seq_num[0] << 16); }
>+
>+static inline
>+void drm_hdcp2_u32_to_seq_num(u8 seq_num[HDCP_2_2_SEQ_NUM_LEN],
>u32
>+val) {
>+ seq_num[0] = val >> 16;
>+ seq_num[1] = val >> 8;
>+ seq_num[2] = val;
>+}
>+
> #endif
>--
>2.7.4