[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <4tt5hs7fztjwoa3nf2f4yvdyaj3izvmqsi6kdh3rsldarn5wj6@qczfv6uzfxbw>
Date: Wed, 19 Feb 2025 14:45:12 +0200
From: Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To: Yongbang Shi <shiyongbang@...wei.com>
Cc: xinliang.liu@...aro.org, tiantao6@...ilicon.com,
maarten.lankhorst@...ux.intel.com, mripard@...nel.org, tzimmermann@...e.de, airlied@...il.com,
daniel@...ll.ch, kong.kongxinwei@...ilicon.com, liangjian010@...wei.com,
chenjianmin@...wei.com, lidongming5@...wei.com, libaihan@...wei.com,
shenjian15@...wei.com, shaojijie@...wei.com, dri-devel@...ts.freedesktop.org,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 drm-dp 2/7] drm/hisilicon/hibmc: Add dp serdes cfg in
dp process
On Wed, Feb 19, 2025 at 03:39:10PM +0800, Yongbang Shi wrote:
> > On Mon, Feb 10, 2025 at 10:49:54PM +0800, Yongbang Shi wrote:
> > > From: Baihan Li <libaihan@...wei.com>
> > >
> > > Add dp serdes cfg in link training process, and related adapting
> > > and modificating. We change some init values about training,
> > Imperative language, please. Use 'change', not 'we change'.
> >
> > > because we want completely to negotiation process, so we start with
> > > the maximum rate and the electrical characteristic level is 0.
> > >
> > > Signed-off-by: Baihan Li <libaihan@...wei.com>
> > > Signed-off-by: Yongbang Shi <shiyongbang@...wei.com>
> > > ---
> > > ChangeLog:
> > > v1 -> v2:
> > > - splittting the patch and add more detailed the changes in the commit message, suggested by Dmitry Baryshkov.
> > > ---
> > > .../gpu/drm/hisilicon/hibmc/dp/dp_config.h | 1 +
> > > drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c | 6 +++-
> > > drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c | 33 ++++++++++++++++---
> > > drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h | 1 +
> > > .../gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c | 8 ++---
> > > 5 files changed, 38 insertions(+), 11 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h
> > > index 74dd9956144e..c5feef8dc27d 100644
> > > --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h
> > > +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_config.h
> > > @@ -15,5 +15,6 @@
> > > #define HIBMC_DP_CLK_EN 0x7
> > > #define HIBMC_DP_SYNC_EN_MASK 0x3
> > > #define HIBMC_DP_LINK_RATE_CAL 27
> > > +#define HIBMC_DP_SYNC_DELAY(lanes) ((lanes) == 0x2 ? 86 : 46)
> > > #endif
> > > diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> > > index 39fd3687efca..ee1ff205ff56 100644
> > > --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> > > +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_hw.c
> > > @@ -3,6 +3,7 @@
> > > #include <linux/io.h>
> > > #include <linux/delay.h>
> > > +#include <drm/drm_managed.h>
> > > #include "dp_config.h"
> > > #include "dp_comm.h"
> > > #include "dp_reg.h"
> > > @@ -73,6 +74,9 @@ static void hibmc_dp_set_sst(struct hibmc_dp_dev *dp, struct drm_display_mode *m
> > > HIBMC_DP_CFG_STREAM_HTOTAL_SIZE, htotal_size);
> > > hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_HORIZONTAL_SIZE,
> > > HIBMC_DP_CFG_STREAM_HBLANK_SIZE, hblank_size);
> > > + hibmc_dp_reg_write_field(dp, HIBMC_DP_VIDEO_PACKET,
> > > + HIBMC_DP_CFG_STREAM_SYNC_CALIBRATION,
> > > + HIBMC_DP_SYNC_DELAY(dp->link.cap.lanes));
> > > }
> > > static void hibmc_dp_link_cfg(struct hibmc_dp_dev *dp, struct drm_display_mode *mode)
> > > @@ -170,7 +174,7 @@ int hibmc_dp_hw_init(struct hibmc_dp *dp)
> > > return -EAGAIN;
> > > dp_dev->link.cap.lanes = 0x2;
> > > - dp_dev->link.cap.link_rate = DP_LINK_BW_2_7;
> > > + dp_dev->link.cap.link_rate = DP_LINK_BW_8_1;
> > > /* hdcp data */
> > > writel(HIBMC_DP_HDCP, dp_dev->base + HIBMC_DP_HDCP_CFG);
> > > diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
> > > index f6355c16cc0a..43a4b656493f 100644
> > > --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
> > > +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_link.c
> > > @@ -6,6 +6,7 @@
> > > #include <drm/drm_print.h>
> > > #include "dp_comm.h"
> > > #include "dp_reg.h"
> > > +#include "dp_serdes.h"
> > > #define HIBMC_EQ_MAX_RETRY 5
> > > @@ -108,7 +109,11 @@ static int hibmc_dp_link_training_cr_pre(struct hibmc_dp_dev *dp)
> > > return ret;
> > > for (i = 0; i < dp->link.cap.lanes; i++)
> > > - train_set[i] = DP_TRAIN_VOLTAGE_SWING_LEVEL_2;
> > > + train_set[i] = DP_TRAIN_VOLTAGE_SWING_LEVEL_0;
> > > +
> > > + ret = hibmc_dp_serdes_set_tx_cfg(dp, dp->link.train_set);
> > > + if (ret)
> > > + return ret;
> > > ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, train_set, dp->link.cap.lanes);
> > > if (ret != dp->link.cap.lanes) {
> > > @@ -137,21 +142,28 @@ static bool hibmc_dp_link_get_adjust_train(struct hibmc_dp_dev *dp,
> > > return false;
> > > }
> > > -static inline int hibmc_dp_link_reduce_rate(struct hibmc_dp_dev *dp)
> > > +static int hibmc_dp_link_reduce_rate(struct hibmc_dp_dev *dp)
> > > {
> > > + u8 rate = 0;
> > > +
> > > switch (dp->link.cap.link_rate) {
> > > case DP_LINK_BW_2_7:
> > > dp->link.cap.link_rate = DP_LINK_BW_1_62;
> > > - return 0;
> > > + rate = DP_SERDES_BW_1_62;
> > > + break;
> > > case DP_LINK_BW_5_4:
> > > dp->link.cap.link_rate = DP_LINK_BW_2_7;
> > > - return 0;
> > > + rate = DP_SERDES_BW_2_7;
> > > + break;
> > > case DP_LINK_BW_8_1:
> > > dp->link.cap.link_rate = DP_LINK_BW_5_4;
> > > - return 0;
> > > + rate = DP_SERDES_BW_5_4;
> > > + break;
> > > default:
> > > return -EINVAL;
> > > }
> > > +
> > > + return hibmc_dp_serdes_rate_switch(rate, dp);
> > This looks like:
> >
> > if (dp->link.cap.link_rate == DP_LINK_BW_1_62)
> > return -EINVAL;
> >
> > dp->link.cap.link_rate++;
> > return hibmc_dp_serdes_rate_switch(rate, dp);
>
> We need map DP_LINK_BW_2_7 to DP_SERDES_BW's value firstly, which is for our SERDES' register cfg.
> This value is not like 0x6, 0xa, etc.
Ack
>
>
> > > }
> > > static inline int hibmc_dp_link_reduce_lane(struct hibmc_dp_dev *dp)
> > > @@ -159,6 +171,7 @@ static inline int hibmc_dp_link_reduce_lane(struct hibmc_dp_dev *dp)
> > > switch (dp->link.cap.lanes) {
> > > case 0x2:
> > > dp->link.cap.lanes--;
> > > + drm_warn(dp->dev, "dp link training reduce to 1 lane\n");
> > drm_dbg
> >
> > > break;
> > > case 0x1:
> > > drm_err(dp->dev, "dp link training reduce lane failed, already reach minimum\n");
> > > @@ -206,6 +219,11 @@ static int hibmc_dp_link_training_cr(struct hibmc_dp_dev *dp)
> > > }
> > > level_changed = hibmc_dp_link_get_adjust_train(dp, lane_status);
> > > +
> > > + ret = hibmc_dp_serdes_set_tx_cfg(dp, dp->link.train_set);
> > > + if (ret)
> > > + return ret;
> > > +
> > > ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET, dp->link.train_set,
> > > dp->link.cap.lanes);
> > > if (ret != dp->link.cap.lanes) {
> > > @@ -255,6 +273,11 @@ static int hibmc_dp_link_training_channel_eq(struct hibmc_dp_dev *dp)
> > > }
> > > hibmc_dp_link_get_adjust_train(dp, lane_status);
> > > +
> > > + ret = hibmc_dp_serdes_set_tx_cfg(dp, dp->link.train_set);
> > > + if (ret)
> > > + return ret;
> > > +
> > > ret = drm_dp_dpcd_write(&dp->aux, DP_TRAINING_LANE0_SET,
> > > dp->link.train_set, dp->link.cap.lanes);
> > > if (ret != dp->link.cap.lanes) {
> > > diff --git a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h
> > > index 4a515c726d52..f2fa9807d8ab 100644
> > > --- a/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h
> > > +++ b/drivers/gpu/drm/hisilicon/hibmc/dp/dp_reg.h
> > > @@ -72,5 +72,6 @@
> > > #define HIBMC_DP_CFG_STREAM_TU_SYMBOL_FRAC_SIZE GENMASK(9, 6)
> > > #define HIBMC_DP_CFG_STREAM_HTOTAL_SIZE GENMASK(31, 16)
> > > #define HIBMC_DP_CFG_STREAM_HBLANK_SIZE GENMASK(15, 0)
> > > +#define HIBMC_DP_CFG_STREAM_SYNC_CALIBRATION GENMASK(31, 20)
> > Please consider restructuring the header so that it becomes more
> > obvious, which register are these masks for.
> >
> > > #endif
> > > diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> > > index e6de6d5edf6b..bade693d9730 100644
> > > --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> > > +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.c
> > > @@ -28,9 +28,7 @@
> > > #include "hibmc_drm_drv.h"
> > > #include "hibmc_drm_regs.h"
> > > -#define HIBMC_DP_HOST_SERDES_CTRL 0x1f001c
> > > -#define HIBMC_DP_HOST_SERDES_CTRL_VAL 0x8a00
> > > -#define HIBMC_DP_HOST_SERDES_CTRL_MASK 0x7ffff
> > > +#define HIBMC_DP_HOST_SERDES_CTRL 0x1f001c
> > Unnecessary whitespace change.
> >
> > Why HIBMC_DP_HOST_SERDES_CTRL is not in the dp_reg.h?
> >
> > > DEFINE_DRM_GEM_FOPS(hibmc_fops);
> > > @@ -122,8 +120,8 @@ static int hibmc_kms_init(struct hibmc_drm_private *priv)
> > > }
> > > /* if DP existed, init DP */
> > > - if ((readl(priv->mmio + HIBMC_DP_HOST_SERDES_CTRL) &
> > > - HIBMC_DP_HOST_SERDES_CTRL_MASK) == HIBMC_DP_HOST_SERDES_CTRL_VAL) {
> > > + ret = readl(priv->mmio + HIBMC_DP_HOST_SERDES_CTRL);
> > > + if (ret) {
> > > ret = hibmc_dp_init(priv);
> > > if (ret)
> > > drm_err(dev, "failed to init dp: %d\n", ret);
> > > --
> > > 2.33.0
> > >
--
With best wishes
Dmitry
Powered by blists - more mailing lists