On Mon, 02 Dec 2019, Chandan Uddaraju chandanu@codeaurora.org wrote:

The constant N value (0x8000) is used by multiple DP drivers. Define this value in header file and use this in the existing i915 display driver.

Signed-off-by: Chandan Uddaraju chandanu@codeaurora.org

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

and ack for merging via drm-misc or whichever tree you find suitable.

---

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 ce05e80..1a4ccfd 100644 --- a/drivers/gpu/drm/i915/display/intel_display.c +++ b/drivers/gpu/drm/i915/display/intel_display.c @@ -7496,7 +7496,7 @@ 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 8364502..69b8251 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1357,6 +1357,7 @@ int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux,

• DisplayPort link

*/ #define DP_LINK_CAP_ENHANCED_FRAMING (1 << 0) +#define DP_LINK_CONSTANT_N_VALUE 0x8000

struct drm_dp_link { unsigned char revision;