[Intel-gfx] [PATCH] drm/i915: Detect USB-C specific dongles before reducing M and N
Clint Taylor
clinton.a.taylor at intel.com
Thu May 11 16:21:19 UTC 2017
On 05/11/2017 03:03 AM, Jani Nikula wrote:
> On Wed, 10 May 2017, clinton.a.taylor at intel.com wrote:
>> From: Clint Taylor <clinton.a.taylor at intel.com>
>>
>> The Analogix 7737 DP to HDMI converter requires reduced N and M values when
>> to operate correctly at HBR2. Detect this IC by its OUI value of 0x0022B9.
> I'm not happy, but I also see no alternative than to go this
> route. Thanks for the patch. I do think we need to start a common drm
> quirk database for this stuff though. Added one, and rebased this one on
> top:
>
> https://patchwork.freedesktop.org/series/24282/
>
> Please give it a go; I don't have a DA200.
patches work as expected. quirks is set correctly when OUI 0x0022B9
based DA200 and SlimPort USB-C dongles are used. All other dongles
tested do not set quirks.
[ 64.569833] [drm:intel_dp_read_desc] DP branch: OUI 00-1c-f8 dev-ID
176GB0 HW-rev 1.0 SW-rev 7.38 quirks 0x0000
[ 111.053902] [drm:intel_dp_read_desc] DP branch: OUI 00-22-b9 dev-ID
7737 HW-rev 10.12 SW-rev 6.4 quirks 0x0001
-Clint
>
>
> BR,
> Jani.
>
>> Cc: Jani Nikula <jani.nikula at intel.com>
>> Cc: Dhinakaran Pandiyan <dhinakaran.pandiyan at intel.com>
>>
>> Signed-off-by: Clint Taylor <clinton.a.taylor at intel.com>
>> ---
>> drivers/gpu/drm/i915/i915_drv.h | 3 ++-
>> drivers/gpu/drm/i915/intel_display.c | 22 ++++++++++++++--------
>> drivers/gpu/drm/i915/intel_dp.c | 22 ++++++++++++++++++++--
>> drivers/gpu/drm/i915/intel_dp_mst.c | 3 ++-
>> drivers/gpu/drm/i915/intel_drv.h | 1 +
>> 5 files changed, 39 insertions(+), 12 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index 74dffbe..492e47e 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -563,7 +563,8 @@ struct intel_link_m_n {
>>
>> void intel_link_compute_m_n(int bpp, int nlanes,
>> int pixel_clock, int link_clock,
>> - struct intel_link_m_n *m_n);
>> + struct intel_link_m_n *m_n,
>> + bool reduce_m_n);
>>
>> /* Interface history:
>> *
>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> index 7bcc604..8920a99 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -6104,7 +6104,7 @@ static int ironlake_fdi_compute_config(struct intel_crtc *intel_crtc,
>> pipe_config->fdi_lanes = lane;
>>
>> intel_link_compute_m_n(pipe_config->pipe_bpp, lane, fdi_dotclock,
>> - link_bw, &pipe_config->fdi_m_n);
>> + link_bw, &pipe_config->fdi_m_n, false);
>>
>> ret = ironlake_check_fdi_lanes(dev, intel_crtc->pipe, pipe_config);
>> if (ret == -EINVAL && pipe_config->pipe_bpp > 6*3) {
>> @@ -6280,7 +6280,8 @@ static int intel_crtc_compute_config(struct intel_crtc *crtc,
>> }
>>
>> static void compute_m_n(unsigned int m, unsigned int n,
>> - uint32_t *ret_m, uint32_t *ret_n)
>> + uint32_t *ret_m, uint32_t *ret_n,
>> + bool reduce_m_n)
>> {
>> /*
>> * Reduce M/N as much as possible without loss in precision. Several DP
>> @@ -6288,9 +6289,11 @@ static void compute_m_n(unsigned int m, unsigned int n,
>> * values. The passed in values are more likely to have the least
>> * significant bits zero than M after rounding below, so do this first.
>> */
>> - while ((m & 1) == 0 && (n & 1) == 0) {
>> - m >>= 1;
>> - n >>= 1;
>> + if (reduce_m_n) {
>> + while ((m & 1) == 0 && (n & 1) == 0) {
>> + m >>= 1;
>> + n >>= 1;
>> + }
>> }
>>
>> *ret_n = min_t(unsigned int, roundup_pow_of_two(n), DATA_LINK_N_MAX);
>> @@ -6301,16 +6304,19 @@ static void compute_m_n(unsigned int m, unsigned int 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)
>> + struct intel_link_m_n *m_n,
>> + bool reduce_m_n)
>> {
>> m_n->tu = 64;
>>
>> compute_m_n(bits_per_pixel * pixel_clock,
>> link_clock * nlanes * 8,
>> - &m_n->gmch_m, &m_n->gmch_n);
>> + &m_n->gmch_m, &m_n->gmch_n,
>> + reduce_m_n);
>>
>> compute_m_n(pixel_clock, link_clock,
>> - &m_n->link_m, &m_n->link_n);
>> + &m_n->link_m, &m_n->link_n,
>> + reduce_m_n);
>> }
>>
>> static inline bool intel_panel_use_ssc(struct drm_i915_private *dev_priv)
>> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>> index 4a6feb6..f4c0582 100644
>> --- a/drivers/gpu/drm/i915/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/intel_dp.c
>> @@ -1548,6 +1548,20 @@ static void intel_dp_print_rates(struct intel_dp *intel_dp)
>> DRM_DEBUG_KMS("common rates: %s\n", str);
>> }
>>
>> +bool __intel_reduced_m_n(struct intel_dp *intel_dp)
>> +{
>> + struct intel_dp_desc *desc = &intel_dp->desc;
>> + bool ret = false;
>> +
>> + /* Analogix 7737 needs reduced N and M at HBR2 link rates */
>> + if (desc->oui[0] == 0x00 &&
>> + desc->oui[1] == 0x22 &&
>> + desc->oui[2] == 0xb9)
>> + ret = true;
>> +
>> + return ret;
>> +}
>> +
>> bool
>> __intel_dp_read_desc(struct intel_dp *intel_dp, struct intel_dp_desc *desc)
>> {
>> @@ -1568,6 +1582,8 @@ bool intel_dp_read_desc(struct intel_dp *intel_dp)
>> if (!__intel_dp_read_desc(intel_dp, desc))
>> return false;
>>
>> + intel_dp->reduce_m_n = __intel_reduced_m_n(intel_dp);
>> +
>> dev_id_len = strnlen(desc->device_id, sizeof(desc->device_id));
>> DRM_DEBUG_KMS("DP %s: OUI %*phD%s dev-ID %*pE HW-rev %d.%d SW-rev %d.%d\n",
>> drm_dp_is_branch(intel_dp->dpcd) ? "branch" : "sink",
>> @@ -1790,7 +1806,8 @@ static int intel_dp_compute_bpp(struct intel_dp *intel_dp,
>> intel_link_compute_m_n(bpp, lane_count,
>> adjusted_mode->crtc_clock,
>> pipe_config->port_clock,
>> - &pipe_config->dp_m_n);
>> + &pipe_config->dp_m_n,
>> + intel_dp->reduce_m_n);
>>
>> if (intel_connector->panel.downclock_mode != NULL &&
>> dev_priv->drrs.type == SEAMLESS_DRRS_SUPPORT) {
>> @@ -1798,7 +1815,8 @@ static int intel_dp_compute_bpp(struct intel_dp *intel_dp,
>> intel_link_compute_m_n(bpp, lane_count,
>> intel_connector->panel.downclock_mode->clock,
>> pipe_config->port_clock,
>> - &pipe_config->dp_m2_n2);
>> + &pipe_config->dp_m2_n2,
>> + intel_dp->reduce_m_n);
>> }
>>
>> /*
>> diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
>> index 68c788e..81fd8dc 100644
>> --- a/drivers/gpu/drm/i915/intel_dp_mst.c
>> +++ b/drivers/gpu/drm/i915/intel_dp_mst.c
>> @@ -79,7 +79,8 @@ static bool intel_dp_mst_compute_config(struct intel_encoder *encoder,
>> intel_link_compute_m_n(bpp, lane_count,
>> adjusted_mode->crtc_clock,
>> pipe_config->port_clock,
>> - &pipe_config->dp_m_n);
>> + &pipe_config->dp_m_n,
>> + intel_dp->reduce_m_n);
>>
>> pipe_config->dp_m_n.tu = slots;
>>
>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>> index e8de2f67..50e5077 100644
>> --- a/drivers/gpu/drm/i915/intel_drv.h
>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>> @@ -1057,6 +1057,7 @@ struct intel_dp {
>>
>> /* Displayport compliance testing */
>> struct intel_dp_compliance compliance;
>> + bool reduce_m_n;
>> };
>>
>> struct intel_lspcon {
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