[DPU PATCH v3 2/5] drm: add constant N value in helper file

Chandan Uddaraju chandanu at codeaurora.org
Mon Dec 2 13:47:44 UTC 2019


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 at codeaurora.org>
---
 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;
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project



More information about the dri-devel mailing list