From a65851af59387146a28a928c3e7bb17dabc5db72 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Tue, 23 Apr 2013 15:03:34 +0300 Subject: [PATCH] drm/i915: Make data/link N value power of two MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The BIOS uses power of two values for the data/link N value. Follow suit to make the Zotac DP to dual-HDMI dongle work. v2: Clean up the magic numbers and defines Change the N clamping to be a bit easier on the eye Rename intel_reduce_ratio to intel_reduce_m_n_ratio Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=49402 Signed-off-by: Ville Syrjälä Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=59810 Tested-by: Jesse Barnes Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_reg.h | 12 ++++-------- drivers/gpu/drm/i915/intel_display.c | 26 ++++++++++++++++++-------- 2 files changed, 22 insertions(+), 16 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h index 31de7e4b1f3e..83f9c26e1adb 100644 --- a/drivers/gpu/drm/i915/i915_reg.h +++ b/drivers/gpu/drm/i915/i915_reg.h @@ -2652,14 +2652,14 @@ #define _PIPEB_GMCH_DATA_M 0x71050 /* Transfer unit size for display port - 1, default is 0x3f (for TU size 64) */ -#define PIPE_GMCH_DATA_M_TU_SIZE_MASK (0x3f << 25) -#define PIPE_GMCH_DATA_M_TU_SIZE_SHIFT 25 +#define TU_SIZE(x) (((x)-1) << 25) /* default size 64 */ +#define TU_SIZE_MASK (0x3f << 25) -#define PIPE_GMCH_DATA_M_MASK (0xffffff) +#define DATA_LINK_M_N_MASK (0xffffff) +#define DATA_LINK_N_MAX (0x800000) #define _PIPEA_GMCH_DATA_N 0x70054 #define _PIPEB_GMCH_DATA_N 0x71054 -#define PIPE_GMCH_DATA_N_MASK (0xffffff) /* * Computing Link M and N values for the Display Port link @@ -2674,11 +2674,9 @@ #define _PIPEA_DP_LINK_M 0x70060 #define _PIPEB_DP_LINK_M 0x71060 -#define PIPEA_DP_LINK_M_MASK (0xffffff) #define _PIPEA_DP_LINK_N 0x70064 #define _PIPEB_DP_LINK_N 0x71064 -#define PIPEA_DP_LINK_N_MASK (0xffffff) #define PIPE_GMCH_DATA_M(pipe) _PIPE(pipe, _PIPEA_GMCH_DATA_M, _PIPEB_GMCH_DATA_M) #define PIPE_GMCH_DATA_N(pipe) _PIPE(pipe, _PIPEA_GMCH_DATA_N, _PIPEB_GMCH_DATA_N) @@ -3404,8 +3402,6 @@ #define _PIPEA_DATA_M1 (dev_priv->info->display_mmio_offset + 0x60030) -#define TU_SIZE(x) (((x)-1) << 25) /* default size 64 */ -#define TU_SIZE_MASK 0x7e000000 #define PIPE_DATA_M1_OFFSET 0 #define _PIPEA_DATA_N1 (dev_priv->info->display_mmio_offset + 0x60034) #define PIPE_DATA_N1_OFFSET 0 diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 6e423e04c35e..efe829919755 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -4084,26 +4084,36 @@ static int i830_get_display_clock_speed(struct drm_device *dev) } static void -intel_reduce_ratio(uint32_t *num, uint32_t *den) +intel_reduce_m_n_ratio(uint32_t *num, uint32_t *den) { - while (*num > 0xffffff || *den > 0xffffff) { + while (*num > DATA_LINK_M_N_MASK || + *den > DATA_LINK_M_N_MASK) { *num >>= 1; *den >>= 1; } } +static void compute_m_n(unsigned int m, unsigned int n, + uint32_t *ret_m, uint32_t *ret_n) +{ + *ret_n = min_t(unsigned int, roundup_pow_of_two(n), DATA_LINK_N_MAX); + *ret_m = div_u64((uint64_t) m * *ret_n, n); + intel_reduce_m_n_ratio(ret_m, ret_n); +} + void intel_link_compute_m_n(int bits_per_pixel, int nlanes, int pixel_clock, int link_clock, struct intel_link_m_n *m_n) { m_n->tu = 64; - m_n->gmch_m = bits_per_pixel * pixel_clock; - m_n->gmch_n = link_clock * nlanes * 8; - intel_reduce_ratio(&m_n->gmch_m, &m_n->gmch_n); - m_n->link_m = pixel_clock; - m_n->link_n = link_clock; - intel_reduce_ratio(&m_n->link_m, &m_n->link_n); + + compute_m_n(bits_per_pixel * pixel_clock, + link_clock * nlanes * 8, + &m_n->gmch_m, &m_n->gmch_n); + + compute_m_n(pixel_clock, link_clock, + &m_n->link_m, &m_n->link_n); } static inline bool intel_panel_use_ssc(struct drm_i915_private *dev_priv) -- 2.34.1