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Message-ID: <20180129213132.wmkhg45bt24dnuog@art_vandelay>
Date: Mon, 29 Jan 2018 16:31:32 -0500
From: Sean Paul <seanpaul@...omium.org>
To: Thierry Escande <thierry.escande@...labora.com>
Cc: Archit Taneja <architt@...eaurora.org>,
Inki Dae <inki.dae@...sung.com>,
Thierry Reding <thierry.reding@...il.com>,
Sandy Huang <hjc@...k-chips.com>,
Sean Paul <seanpaul@...omium.org>,
David Airlie <airlied@...ux.ie>,
Tomasz Figa <tfiga@...omium.org>,
Haixia Shi <hshi@...omium.org>,
Ørjan Eide <orjan.eide@....com>,
Zain Wang <wzz@...k-chips.com>,
Yakir Yang <ykk@...k-chips.com>, Lin Huang <hl@...k-chips.com>,
Douglas Anderson <dianders@...omium.org>,
Mark Yao <mark.yao@...k-chips.com>,
linux-kernel@...r.kernel.org, linux-rockchip@...ts.infradead.org,
dri-devel@...ts.freedesktop.org
Subject: Re: [PATCH v2 22/43] drm/bridge: analogix_dp: Check dpcd write/read
status
On Mon, Jan 29, 2018 at 04:14:41PM -0500, Sean Paul wrote:
> On Fri, Jan 26, 2018 at 02:16:49PM +0100, Thierry Escande wrote:
> > From: Lin Huang <hl@...k-chips.com>
> >
> > We need to check the dpcd write/read return value to see whether the
> > write/read was successful
> >
> > Cc: Kristian H. Kristensen <hoegsberg@...omium.org>
> > Signed-off-by: Lin Huang <hl@...k-chips.com>
> > Signed-off-by: zain wang <wzz@...k-chips.com>
> > Signed-off-by: Douglas Anderson <dianders@...omium.org>
> > Signed-off-by: Sean Paul <seanpaul@...omium.org>
> > Signed-off-by: Thierry Escande <thierry.escande@...labora.com>
> > Reviewed-by: Andrzej Hajda <a.hajda@...sung.com>
> > ---
> > drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 181 +++++++++++++++------
> > 1 file changed, 132 insertions(+), 49 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> > index 846574d0dcb0..501f7b4a23d6 100644
> > --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> > +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
> > @@ -160,80 +160,135 @@ int analogix_dp_disable_psr(struct analogix_dp_device *dp)
> > }
> > EXPORT_SYMBOL_GPL(analogix_dp_disable_psr);
> >
> > -static bool analogix_dp_detect_sink_psr(struct analogix_dp_device *dp)
> > +static int analogix_dp_detect_sink_psr(struct analogix_dp_device *dp)
> > {
> > unsigned char psr_version;
> > + int ret;
> > +
> > + ret = drm_dp_dpcd_readb(&dp->aux, DP_PSR_SUPPORT, &psr_version);
> > + if (ret != 1) {
> > + dev_err(dp->dev, "failed to get PSR version, disable it\n");
> > + return ret;
> > + }
> >
> > - drm_dp_dpcd_readb(&dp->aux, DP_PSR_SUPPORT, &psr_version);
> > dev_dbg(dp->dev, "Panel PSR version : %x\n", psr_version);
> >
> > - return (psr_version & DP_PSR_IS_SUPPORTED) ? true : false;
> > + dp->psr_enable = (psr_version & DP_PSR_IS_SUPPORTED) ? true : false;
> > +
> > + return 0;
> > }
> >
> > -static void analogix_dp_enable_sink_psr(struct analogix_dp_device *dp)
> > +static int analogix_dp_enable_sink_psr(struct analogix_dp_device *dp)
> > {
> > unsigned char psr_en;
> > + int ret;
> >
> > /* Disable psr function */
> > - drm_dp_dpcd_readb(&dp->aux, DP_PSR_EN_CFG, &psr_en);
> > + ret = drm_dp_dpcd_readb(&dp->aux, DP_PSR_EN_CFG, &psr_en);
> > + if (ret != 1) {
> > + dev_err(dp->dev, "failed to get psr config\n");
> > + goto end;
> > + }
> > +
> > psr_en &= ~DP_PSR_ENABLE;
> > - drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
> > + ret = drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
> > + if (ret != 1) {
> > + dev_err(dp->dev, "failed to disable panel psr\n");
> > + goto end;
> > + }
> >
> > /* Main-Link transmitter remains active during PSR active states */
> > psr_en = DP_PSR_MAIN_LINK_ACTIVE | DP_PSR_CRC_VERIFICATION;
> > - drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
> > + ret = drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
> > + if (ret != 1) {
> > + dev_err(dp->dev, "failed to set panel psr\n");
> > + goto end;
> > + }
> >
> > /* Enable psr function */
> > psr_en = DP_PSR_ENABLE | DP_PSR_MAIN_LINK_ACTIVE |
> > DP_PSR_CRC_VERIFICATION;
> > - drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
> > + ret = drm_dp_dpcd_writeb(&dp->aux, DP_PSR_EN_CFG, psr_en);
> > + if (ret != 1) {
> > + dev_err(dp->dev, "failed to set panel psr\n");
> > + goto end;
> > + }
> >
> > analogix_dp_enable_psr_crc(dp);
> > +
> > + return 0;
> > +end:
> > + dev_err(dp->dev, "enable psr fail, force to disable psr\n");
> > + dp->psr_enable = false;
> > +
> > + return ret;
> > }
> >
> > -static void
> > +static int
> > analogix_dp_enable_rx_to_enhanced_mode(struct analogix_dp_device *dp,
> > bool enable)
> > {
> > u8 data;
> > + int ret;
> >
> > - drm_dp_dpcd_readb(&dp->aux, DP_LANE_COUNT_SET, &data);
> > + ret = drm_dp_dpcd_readb(&dp->aux, DP_LANE_COUNT_SET, &data);
> > + if (ret < 0)
> > + return ret;
> >
> > if (enable)
> > - drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET,
> > - DP_LANE_COUNT_ENHANCED_FRAME_EN |
> > - DPCD_LANE_COUNT_SET(data));
> > + ret = drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET,
> > + DP_LANE_COUNT_ENHANCED_FRAME_EN |
> > + DPCD_LANE_COUNT_SET(data));
> > else
> > - drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET,
> > - DPCD_LANE_COUNT_SET(data));
> > + ret = drm_dp_dpcd_writeb(&dp->aux, DP_LANE_COUNT_SET,
> > + DPCD_LANE_COUNT_SET(data));
> > +
> > + return ret < 0 ? ret : 0;
> > }
> >
> > -static int analogix_dp_is_enhanced_mode_available(struct analogix_dp_device *dp)
> > +static int analogix_dp_is_enhanced_mode_available(struct analogix_dp_device *dp,
> > + u8 *enhanced_mode_support)
> > {
> > u8 data;
> > - int retval;
> > + int ret;
> >
> > - drm_dp_dpcd_readb(&dp->aux, DP_MAX_LANE_COUNT, &data);
> > - retval = DPCD_ENHANCED_FRAME_CAP(data);
> > + ret = drm_dp_dpcd_readb(&dp->aux, DP_MAX_LANE_COUNT, &data);
> > + if (ret < 0)
>
> Above we check for ret != 1, so we should probably stay consistent. Same nit
> throughout the patch.
>
> > + return ret;
> >
> > - return retval;
> > + *enhanced_mode_support = DPCD_ENHANCED_FRAME_CAP(data);
> > +
> > + return 0;
> > }
> >
> > -static void analogix_dp_set_enhanced_mode(struct analogix_dp_device *dp)
> > +static int analogix_dp_set_enhanced_mode(struct analogix_dp_device *dp)
> > {
> > u8 data;
> > + int ret;
> > +
> > + ret = analogix_dp_is_enhanced_mode_available(dp, &data);
> > + if (ret < 0)
> > + return ret;
> > +
> > + ret = analogix_dp_enable_rx_to_enhanced_mode(dp, data);
> > + if (ret < 0)
> > + return ret;
> >
> > - data = analogix_dp_is_enhanced_mode_available(dp);
> > - analogix_dp_enable_rx_to_enhanced_mode(dp, data);
> > analogix_dp_enable_enhanced_mode(dp, data);
> > +
> > + return 0;
> > }
> >
> > -static void analogix_dp_training_pattern_dis(struct analogix_dp_device *dp)
> > +static int analogix_dp_training_pattern_dis(struct analogix_dp_device *dp)
> > {
> > + int retval;
>
> Above we're replacing retval with ret, however here we introduce retval.
>
> > +
> > analogix_dp_set_training_pattern(dp, DP_NONE);
> >
> > - drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
> > - DP_TRAINING_PATTERN_DISABLE);
> > + retval = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
> > + DP_TRAINING_PATTERN_DISABLE);
> > +
> > + return retval < 0 ? retval : 0;
> > }
> >
> > static void
> > @@ -282,7 +337,11 @@ static int analogix_dp_link_start(struct analogix_dp_device *dp)
> > if (retval < 0)
> > return retval;
> > /* set enhanced mode if available */
> > - analogix_dp_set_enhanced_mode(dp);
> > + retval = analogix_dp_set_enhanced_mode(dp);
> > + if (retval < 0) {
> > + dev_err(dp->dev, "failed to set enhance mode\n");
> > + return retval;
> > + }
> >
> > /* Set TX pre-emphasis to minimum */
> > for (lane = 0; lane < lane_count; lane++)
> > @@ -567,10 +626,11 @@ static int analogix_dp_process_equalizer_training(struct analogix_dp_device *dp)
> >
> > if (!analogix_dp_channel_eq_ok(link_status, link_align, lane_count)) {
> > /* traing pattern Set to Normal */
> > - analogix_dp_training_pattern_dis(dp);
> > + retval = analogix_dp_training_pattern_dis(dp);
> > + if (retval < 0)
> > + return retval;
> >
> > dev_info(dp->dev, "Link Training success!\n");
> > -
> > analogix_dp_get_link_bandwidth(dp, ®);
> > dp->link_train.link_rate = reg;
> > dev_dbg(dp->dev, "final bandwidth = %.2x\n",
> > @@ -807,7 +867,6 @@ static int analogix_dp_train_link(struct analogix_dp_device *dp)
> >
> > static int analogix_dp_config_video(struct analogix_dp_device *dp)
> > {
> > - int retval = 0;
> > int timeout_loop = 0;
> > int done_count = 0;
> >
> > @@ -825,8 +884,9 @@ static int analogix_dp_config_video(struct analogix_dp_device *dp)
> > if (analogix_dp_is_slave_video_stream_clock_on(dp) == 0)
> > break;
> > if (timeout_loop > DP_TIMEOUT_LOOP_COUNT) {
> > - dev_err(dp->dev, "Timeout of slave video streamclk ok\n");
> > - return -ETIMEDOUT;
> > + dev_warn(dp->dev,
> > + "Ignoring timeout of slave video streamclk ok\n");
> > + break;
>
> This change has sort of snuck in here. It doesn't seem related to the change,
> but maybe I'm overlooking something.
>
Ah, this looks to be reversed in patch 27, hopefully we can rationalize things
a bit.
Sean
> > }
> > usleep_range(1000, 1001);
>
> Unrelated: This is pretty hilarious.
>
> > }
> > @@ -865,30 +925,38 @@ static int analogix_dp_config_video(struct analogix_dp_device *dp)
> > usleep_range(1000, 1001);
> > }
> >
> > - if (retval != 0)
> > - dev_err(dp->dev, "Video stream is not detected!\n");
> > -
> > - return retval;
> > + return 0;
> > }
> >
> > -static void analogix_dp_enable_scramble(struct analogix_dp_device *dp,
> > - bool enable)
> > +static int analogix_dp_enable_scramble(struct analogix_dp_device *dp,
> > + bool enable)
> > {
> > u8 data;
> > + int ret;
> >
> > if (enable) {
> > analogix_dp_enable_scrambling(dp);
> >
> > - drm_dp_dpcd_readb(&dp->aux, DP_TRAINING_PATTERN_SET, &data);
> > - drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
> > + ret = drm_dp_dpcd_readb(&dp->aux, DP_TRAINING_PATTERN_SET,
> > + &data);
> > + if (ret != 1)
> > + return ret;
> > +
> > + ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
> > (u8)(data & ~DP_LINK_SCRAMBLING_DISABLE));
> > } else {
> > analogix_dp_disable_scrambling(dp);
> >
> > - drm_dp_dpcd_readb(&dp->aux, DP_TRAINING_PATTERN_SET, &data);
> > - drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
> > + ret = drm_dp_dpcd_readb(&dp->aux, DP_TRAINING_PATTERN_SET,
> > + &data);
> > + if (ret != 1)
> > + return ret;
> > +
> > + ret = drm_dp_dpcd_writeb(&dp->aux, DP_TRAINING_PATTERN_SET,
> > (u8)(data | DP_LINK_SCRAMBLING_DISABLE));
>
> This should probably be explicitly checked as well, since the inline conditional
> in the return isn't checking what the rest of the function is.
>
> > }
> > +
> > + return ret < 0 ? ret : 0;
> > }
> >
> > static irqreturn_t analogix_dp_hardirq(int irq, void *arg)
> > @@ -943,23 +1011,36 @@ static int analogix_dp_commit(struct analogix_dp_device *dp)
> > return ret;
> > }
> >
> > - analogix_dp_enable_scramble(dp, 1);
> > + ret = analogix_dp_enable_scramble(dp, 1);
> > + if (ret < 0) {
> > + dev_err(dp->dev, "can not enable scramble\n");
> > + return ret;
> > + }
> >
> > analogix_dp_init_video(dp);
> > ret = analogix_dp_config_video(dp);
> > - if (ret)
> > + if (ret) {
> > dev_err(dp->dev, "unable to config video\n");
> > + return ret;
> > + }
> >
> > /* Safe to enable the panel now */
> > if (dp->plat_data->panel) {
> > - if (drm_panel_enable(dp->plat_data->panel))
> > + ret = drm_panel_enable(dp->plat_data->panel);
> > + if (ret) {
> > DRM_ERROR("failed to enable the panel\n");
> > + return ret;
> > + }
> > }
> >
> > - dp->psr_enable = analogix_dp_detect_sink_psr(dp);
> > + ret = analogix_dp_detect_sink_psr(dp);
> > + if (ret)
> > + return ret;
> > +
> > if (dp->psr_enable)
> > - analogix_dp_enable_sink_psr(dp);
> > - return 0;
> > + ret = analogix_dp_enable_sink_psr(dp);
> > +
> > + return ret;
> > }
> >
> > /*
> > @@ -1186,8 +1267,10 @@ static int analogix_dp_set_bridge(struct analogix_dp_device *dp)
> > }
> >
> > ret = analogix_dp_commit(dp);
> > - if (ret)
> > + if (ret) {
> > + DRM_ERROR("dp commit error, ret = %d\n", ret);
> > goto out_dp_init;
> > + }
> >
> > enable_irq(dp->irq);
> > return 0;
> > --
> > 2.14.1
> >
>
> --
> Sean Paul, Software Engineer, Google / Chromium OS
--
Sean Paul, Software Engineer, Google / Chromium OS
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