| Message ID | 1521148131-18560-1-git-send-email-matthew.s.atwood@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Mar 15, 2018 at 02:08:51PM -0700, matthew.s.atwood@intel.com wrote: > From: Matt Atwood <matthew.s.atwood@intel.com> > > DP_TRAINING_AUX_RD_INTERVAL with DP 1.3 spec changed bit scheeme from 8 > bits to 7 in DPCD 0x000e. The 8th bit is used to identify extended > receiver capabilities. For panels that use this new feature wait interval > would be increased by 512 ms, when spec is max 16 ms. This behavior is > described in table 2-158 of DP 1.4 spec address 0000eh. > > With the introduction of DP 1.4 spec main link clock recovery was > standardized to 100 us regardless of TRAINING_AUX_RD_INTERVAL value. > > To avoid breaking panels that are not spec compiant we now warn on > invalid values. > > V2: commit title/message, masking all 7 bits, warn on out of spec values. > V3: commit message, make link train clock recovery follow DP 1.4 spec. > V4: style changes > V5: typo > V6: print statement revisions, DP_REV to DPCD_REV, comment correction > V7: typo > V8: Style thanks :) > > Signed-off-by: Matt Atwood <matthew.s.atwood@intel.com> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com> > --- > drivers/gpu/drm/drm_dp_helper.c | 22 ++++++++++++++++++---- > include/drm/drm_dp_helper.h | 6 ++++++ > 2 files changed, 24 insertions(+), 4 deletions(-) > > diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c > index adf79be..6bee2df 100644 > --- a/drivers/gpu/drm/drm_dp_helper.c > +++ b/drivers/gpu/drm/drm_dp_helper.c > @@ -119,18 +119,32 @@ u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SI > EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis); > > void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { > - if (dpcd[DP_TRAINING_AUX_RD_INTERVAL] == 0) > + int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] & > + DP_TRAINING_AUX_RD_MASK; > + > + if (rd_interval > 4) > + DRM_DEBUG_KMS("AUX interval %d, out of range (max 4)\n", > + rd_interval); > + > + if (rd_interval == 0 || dpcd[DP_DPCD_REV] >= DPCD_REV_14) > udelay(100); > else > - mdelay(dpcd[DP_TRAINING_AUX_RD_INTERVAL] * 4); > + mdelay(rd_interval * 4); > } > EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay); > > void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { > - if (dpcd[DP_TRAINING_AUX_RD_INTERVAL] == 0) > + int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] & > + DP_TRAINING_AUX_RD_MASK; > + > + if (rd_interval > 4) > + DRM_DEBUG_KMS("AUX interval %d, out of range (max 4)\n", > + rd_interval); > + > + if (rd_interval == 0) > udelay(400); > else > - mdelay(dpcd[DP_TRAINING_AUX_RD_INTERVAL] * 4); > + mdelay(rd_interval * 4); > } > EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay); > > diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h > index da58a42..8c59ce4 100644 > --- a/include/drm/drm_dp_helper.h > +++ b/include/drm/drm_dp_helper.h > @@ -64,6 +64,11 @@ > /* AUX CH addresses */ > /* DPCD */ > #define DP_DPCD_REV 0x000 > +# define DPCD_REV_10 0x10 > +# define DPCD_REV_11 0x11 > +# define DPCD_REV_12 0x12 > +# define DPCD_REV_13 0x13 > +# define DPCD_REV_14 0x14 > > #define DP_MAX_LINK_RATE 0x001 > > @@ -118,6 +123,7 @@ > # define DP_DPCD_DISPLAY_CONTROL_CAPABLE (1 << 3) /* edp v1.2 or higher */ > > #define DP_TRAINING_AUX_RD_INTERVAL 0x00e /* XXX 1.2? */ > +# define DP_TRAINING_AUX_RD_MASK 0x7F /* XXX 1.2? */ > > #define DP_ADAPTER_CAP 0x00f /* 1.2 */ > # define DP_FORCE_LOAD_SENSE_CAP (1 << 0) > -- > 2.7.4 > > _______________________________________________ > Intel-gfx mailing list > Intel-gfx@lists.freedesktop.org > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
Hi Matt,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on v4.16-rc4]
[also build test ERROR on next-20180316]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
url: https://github.com/0day-ci/linux/commits/matthew-s-atwood-intel-com/drm-dp-Correctly-mask-DP_TRAINING_AUX_RD_INTERVAL-values-for-DP-1-4/20180316-222756
config: x86_64-federa-25 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-1) 7.3.0
reproduce:
# save the attached .config to linux build tree
make ARCH=x86_64
All errors (new ones prefixed by >>):
In file included from drivers/gpu/drm/amd/amdgpu/../display/include/dpcd_defs.h:29:0,
from drivers/gpu/drm/amd/amdgpu/../display/dc/core/dc_link.c:42:
>> include/drm/drm_dp_helper.h:67:45: error: expected identifier before numeric constant
# define DPCD_REV_10 0x10
^
drivers/gpu/drm/amd/amdgpu/../display/include/dpcd_defs.h:32:2: note: in expansion of macro 'DPCD_REV_10'
DPCD_REV_10 = 0x10,
^~~~~~~~~~~
vim +67 include/drm/drm_dp_helper.h
63
64 /* AUX CH addresses */
65 /* DPCD */
66 #define DP_DPCD_REV 0x000
> 67 # define DPCD_REV_10 0x10
68 # define DPCD_REV_11 0x11
69 # define DPCD_REV_12 0x12
70 # define DPCD_REV_13 0x13
71 # define DPCD_REV_14 0x14
72
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
On Thu, Mar 15, 2018 at 02:08:51PM -0700, matthew.s.atwood@intel.com wrote: > From: Matt Atwood <matthew.s.atwood@intel.com> > > DP_TRAINING_AUX_RD_INTERVAL with DP 1.3 spec changed bit scheeme from 8 > bits to 7 in DPCD 0x000e. The 8th bit is used to identify extended > receiver capabilities. For panels that use this new feature wait interval > would be increased by 512 ms, when spec is max 16 ms. This behavior is > described in table 2-158 of DP 1.4 spec address 0000eh. > > With the introduction of DP 1.4 spec main link clock recovery was > standardized to 100 us regardless of TRAINING_AUX_RD_INTERVAL value. > > To avoid breaking panels that are not spec compiant we now warn on > invalid values. > > V2: commit title/message, masking all 7 bits, warn on out of spec values. > V3: commit message, make link train clock recovery follow DP 1.4 spec. > V4: style changes > V5: typo > V6: print statement revisions, DP_REV to DPCD_REV, comment correction > V7: typo > V8: Style > > Signed-off-by: Matt Atwood <matthew.s.atwood@intel.com> Tested-by: Benson Leung <bleung@chromium.org> This version still passes link training on the panel with 8th bit set in DPCD 0x000e. Thanks, Benson
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index adf79be..6bee2df 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -119,18 +119,32 @@ u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SI EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis); void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { - if (dpcd[DP_TRAINING_AUX_RD_INTERVAL] == 0) + int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] & + DP_TRAINING_AUX_RD_MASK; + + if (rd_interval > 4) + DRM_DEBUG_KMS("AUX interval %d, out of range (max 4)\n", + rd_interval); + + if (rd_interval == 0 || dpcd[DP_DPCD_REV] >= DPCD_REV_14) udelay(100); else - mdelay(dpcd[DP_TRAINING_AUX_RD_INTERVAL] * 4); + mdelay(rd_interval * 4); } EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay); void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { - if (dpcd[DP_TRAINING_AUX_RD_INTERVAL] == 0) + int rd_interval = dpcd[DP_TRAINING_AUX_RD_INTERVAL] & + DP_TRAINING_AUX_RD_MASK; + + if (rd_interval > 4) + DRM_DEBUG_KMS("AUX interval %d, out of range (max 4)\n", + rd_interval); + + if (rd_interval == 0) udelay(400); else - mdelay(dpcd[DP_TRAINING_AUX_RD_INTERVAL] * 4); + mdelay(rd_interval * 4); } EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay); diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index da58a42..8c59ce4 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -64,6 +64,11 @@ /* AUX CH addresses */ /* DPCD */ #define DP_DPCD_REV 0x000 +# define DPCD_REV_10 0x10 +# define DPCD_REV_11 0x11 +# define DPCD_REV_12 0x12 +# define DPCD_REV_13 0x13 +# define DPCD_REV_14 0x14 #define DP_MAX_LINK_RATE 0x001 @@ -118,6 +123,7 @@ # define DP_DPCD_DISPLAY_CONTROL_CAPABLE (1 << 3) /* edp v1.2 or higher */ #define DP_TRAINING_AUX_RD_INTERVAL 0x00e /* XXX 1.2? */ +# define DP_TRAINING_AUX_RD_MASK 0x7F /* XXX 1.2? */ #define DP_ADAPTER_CAP 0x00f /* 1.2 */ # define DP_FORCE_LOAD_SENSE_CAP (1 << 0)