On Mon, 08 Jun 2020, Tanmay Shah tanmay@codeaurora.org wrote:

From: Chandan Uddaraju chandanu@codeaurora.org

The constant N value (0x8000) is used by i915 DP driver. Define this value in dp helper header file to use in multiple Display Port drivers. Change i915 driver accordingly.

Change in v6: Change commit message

Signed-off-by: Chandan Uddaraju chandanu@codeaurora.org Signed-off-by: Vara Reddy varar@codeaurora.org Signed-off-by: Tanmay Shah tanmay@codeaurora.org

Acked-by: Jani Nikula jani.nikula@intel.com

for merging via drm-misc if that helps you.

---

drivers/gpu/drm/i915/display/intel_display.c | 2 +- include/drm/drm_dp_helper.h | 1 + 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c index 9ea1a39..4b2cfff 100644 --- a/drivers/gpu/drm/i915/display/intel_display.c +++ b/drivers/gpu/drm/i915/display/intel_display.c @@ -8085,7 +8085,7 @@ static void compute_m_n(unsigned int m, unsigned int n, * which the devices expect also in synchronous clock mode. */ if (constant_n)

• *ret_n = 0x8000;
  

• *ret_n = DP_LINK_CONSTANT_N_VALUE;
  

  else *ret_n = min_t(unsigned int, roundup_pow_of_two(n), DATA_LINK_N_MAX);

diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 2035ac4..589132a 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1134,6 +1134,7 @@ #define DP_MST_PHYSICAL_PORT_0 0 #define DP_MST_LOGICAL_PORT_0 8

+#define DP_LINK_CONSTANT_N_VALUE 0x8000 #define DP_LINK_STATUS_SIZE 6 bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE], int lane_count);