| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <CAHQ1cqF0fPyLpMxSoobD_E4L5bVauE+3TJp6s6F5R2tBKL0X8w@mail.gmail.com>
Date: Tue, 27 Aug 2019 15:55:08 -0700
From: Andrey Smirnov <andrew.smirnov@...il.com>
To: Tomi Valkeinen <tomi.valkeinen@...com>
Cc: dri-devel@...ts.freedesktop.org,
Andrzej Hajda <a.hajda@...sung.com>,
Laurent Pinchart <Laurent.pinchart@...asonboard.com>,
Cory Tusar <cory.tusar@....aero>,
Chris Healy <cphealy@...il.com>,
Lucas Stach <l.stach@...gutronix.de>,
linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] drm/bridge: tc358767: Expose test mode functionality via debugfs
On Mon, Aug 26, 2019 at 10:46 PM Tomi Valkeinen <tomi.valkeinen@...com> wrote:
>
> Hi,
>
> On 26/08/2019 21:25, Andrey Smirnov wrote:
> > Presently, the driver code artificially limits test pattern mode to a
> > single pattern with fixed color selection. It being a kernel module
> > parameter makes switching "test patter" <-> "proper output" modes
> > on-the-fly clunky and outright impossible if the driver is built into
> > the kernel.
> >
> > To improve the situation a bit, convert current test pattern code to
> > use debugfs instead by exposing "TestCtl" register. This way old
> > "tc_test_pattern=1" functionality can be emulated via:
> >
> > echo -n 0x78146312 > tstctl
> >
> > and switch back to regular mode can be done with:
> >
> > echo -n 0x78146310 > tstctl
>
> It might be worth explaining the format in the commit msg or in a
> comment in the driver.
>
Good point. Will do if this is the format going forward.
> > Note that switching to any of the test patterns, will NOT trigger link
> > re-establishment whereas switching to normal operation WILL. This is
> > done so:
> >
> > a) we can isolate and verify (e)DP link functionality by switching to
> > one of the test patters
> >
> > b) trigger a link re-establishment by switching back to normal mode
> >
> > Signed-off-by: Andrey Smirnov <andrew.smirnov@...il.com>
> > Cc: Andrzej Hajda <a.hajda@...sung.com>
> > Cc: Laurent Pinchart <Laurent.pinchart@...asonboard.com>
> > Cc: Tomi Valkeinen <tomi.valkeinen@...com>
> > Cc: Cory Tusar <cory.tusar@....aero>
> > Cc: Chris Healy <cphealy@...il.com>
> > Cc: Lucas Stach <l.stach@...gutronix.de>
> > Cc: dri-devel@...ts.freedesktop.org
> > Cc: linux-kernel@...r.kernel.org
> > ---
> > drivers/gpu/drm/bridge/tc358767.c | 137 ++++++++++++++++++++++--------
> > 1 file changed, 101 insertions(+), 36 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/bridge/tc358767.c b/drivers/gpu/drm/bridge/tc358767.c
> > index 6308d93ad91d..7a795b613ed0 100644
> > --- a/drivers/gpu/drm/bridge/tc358767.c
> > +++ b/drivers/gpu/drm/bridge/tc358767.c
> > @@ -17,6 +17,7 @@
> >
> > #include <linux/bitfield.h>
> > #include <linux/clk.h>
> > +#include <linux/debugfs.h>
> > #include <linux/device.h>
> > #include <linux/gpio/consumer.h>
> > #include <linux/i2c.h>
> > @@ -222,11 +223,10 @@
> > #define COLOR_B GENMASK(15, 8)
> > #define ENI2CFILTER BIT(4)
> > #define COLOR_BAR_MODE GENMASK(1, 0)
> > +#define COLOR_BAR_MODE_NORMAL 0
> > #define COLOR_BAR_MODE_BARS 2
> > -#define PLL_DBG 0x0a04
> >
> > -static bool tc_test_pattern;
> > -module_param_named(test, tc_test_pattern, bool, 0644);
> > +#define PLL_DBG 0x0a04
> >
> > struct tc_edp_link {
> > struct drm_dp_link base;
> > @@ -789,16 +789,6 @@ static int tc_set_video_mode(struct tc_data *tc,
> > if (ret)
> > return ret;
> >
> > - /* Test pattern settings */
> > - ret = regmap_write(tc->regmap, TSTCTL,
> > - FIELD_PREP(COLOR_R, 120) |
> > - FIELD_PREP(COLOR_G, 20) |
> > - FIELD_PREP(COLOR_B, 99) |
> > - ENI2CFILTER |
> > - FIELD_PREP(COLOR_BAR_MODE, COLOR_BAR_MODE_BARS));
> > - if (ret)
> > - return ret;
> > -
> > /* DP Main Stream Attributes */
> > vid_sync_dly = hsync_len + left_margin + mode->hdisplay;
> > ret = regmap_write(tc->regmap, DP0_VIDSYNCDELAY,
> > @@ -1150,14 +1140,6 @@ static int tc_stream_enable(struct tc_data *tc)
> >
> > dev_dbg(tc->dev, "enable video stream\n");
> >
> > - /* PXL PLL setup */
> > - if (tc_test_pattern) {
> > - ret = tc_pxl_pll_en(tc, clk_get_rate(tc->refclk),
> > - 1000 * tc->mode.clock);
> > - if (ret)
> > - return ret;
> > - }
> > -
> > ret = tc_set_video_mode(tc, &tc->mode);
> > if (ret)
> > return ret;
> > @@ -1186,12 +1168,8 @@ static int tc_stream_enable(struct tc_data *tc)
> > if (ret)
> > return ret;
> > /* Set input interface */
> > - value = DP0_AUDSRC_NO_INPUT;
> > - if (tc_test_pattern)
> > - value |= DP0_VIDSRC_COLOR_BAR;
> > - else
> > - value |= DP0_VIDSRC_DPI_RX;
> > - ret = regmap_write(tc->regmap, SYSCTRL, value);
> > + ret = regmap_write(tc->regmap, SYSCTRL,
> > + DP0_AUDSRC_NO_INPUT | DP0_VIDSRC_DPI_RX);
> > if (ret)
> > return ret;
> >
> > @@ -1220,39 +1198,44 @@ static void tc_bridge_pre_enable(struct drm_bridge *bridge)
> > drm_panel_prepare(tc->panel);
> > }
> >
> > -static void tc_bridge_enable(struct drm_bridge *bridge)
> > +static int __tc_bridge_enable(struct tc_data *tc)
> > {
> > - struct tc_data *tc = bridge_to_tc(bridge);
> > int ret;
> >
> > ret = tc_get_display_props(tc);
> > if (ret < 0) {
> > dev_err(tc->dev, "failed to read display props: %d\n", ret);
> > - return;
> > + return ret;
> > }
> >
> > ret = tc_main_link_enable(tc);
> > if (ret < 0) {
> > dev_err(tc->dev, "main link enable error: %d\n", ret);
> > - return;
> > + return ret;
> > }
> >
> > ret = tc_stream_enable(tc);
> > if (ret < 0) {
> > dev_err(tc->dev, "main link stream start error: %d\n", ret);
> > tc_main_link_disable(tc);
> > - return;
> > }
> >
> > - drm_panel_enable(tc->panel);
> > + return ret;
> > }
>
> Maybe it's just me, but I rather have the last if() block do a "return
> ret"; and have "return 0;" at the end of the function to keep all the if
> blocks consistent.
OK, will fix in v2.
>
> >
> > -static void tc_bridge_disable(struct drm_bridge *bridge)
> > +static void tc_bridge_enable(struct drm_bridge *bridge)
> > {
> > struct tc_data *tc = bridge_to_tc(bridge);
> > - int ret;
> >
> > - drm_panel_disable(tc->panel);
> > + if (__tc_bridge_enable(tc) < 0)
> > + return;
> > +
> > + drm_panel_enable(tc->panel);
> > +}
> > +
> > +static int __tc_bridge_disable(struct tc_data *tc)
> > +{
> > + int ret;
> >
> > ret = tc_stream_disable(tc);
> > if (ret < 0)
> > @@ -1261,6 +1244,16 @@ static void tc_bridge_disable(struct drm_bridge *bridge)
> > ret = tc_main_link_disable(tc);
> > if (ret < 0)
> > dev_err(tc->dev, "main link disable error: %d\n", ret);
> > +
> > + return ret;
> > +}
> > +
> > +static void tc_bridge_disable(struct drm_bridge *bridge)
> > +{
> > + struct tc_data *tc = bridge_to_tc(bridge);
> > +
> > + drm_panel_disable(tc->panel);
> > + __tc_bridge_disable(tc);
> > }
>
> Maybe have this enable/disable change as a separate patch?
>
Sure, I can do that in v2.
> >
> > static void tc_bridge_post_disable(struct drm_bridge *bridge)
> > @@ -1372,6 +1365,77 @@ static enum drm_connector_status tc_connector_detect(struct drm_connector *conne
> > return connector_status_disconnected;
> > }
> >
> > +static int tc_tstctl_set(void *data, u64 val)
> > +{
> > + struct tc_data *tc = data;
> > + int ret;
> > +
> > + if (FIELD_GET(COLOR_BAR_MODE, val) == COLOR_BAR_MODE_NORMAL) {
> > + ret = regmap_write(tc->regmap, SYSCTRL, DP0_VIDSRC_DPI_RX);
> > + if (ret) {
> > + dev_err(tc->dev,
> > + "failed to select dpi video stream\n");
> > + return ret;
> > + }
> > +
> > + ret = regmap_write(tc->regmap, TSTCTL, val | ENI2CFILTER);
> > + if (ret) {
> > + dev_err(tc->dev, "failed to set TSTCTL\n");
> > + return ret;
> > + }
> > +
> > + ret = tc_pxl_pll_dis(tc);
> > + if (ret) {
> > + dev_err(tc->dev, "failed to disable PLL\n");
> > + return ret;
> > + }
> > +
> > + /*
> > + * Re-establish DP link
> > + */
> > + ret = __tc_bridge_disable(tc);
> > + if (ret)
> > + return ret;
> > +
> > + ret = __tc_bridge_enable(tc);
> > + if (ret)
> > + return ret;
> > + } else {
> > + ret = tc_pxl_pll_en(tc, clk_get_rate(tc->refclk),
> > + 1000 * tc->mode.clock);
> > + if (ret) {
> > + dev_err(tc->dev, "failed to enable PLL\n");
> > + return ret;
> > + }
> > +
> > + ret = regmap_write(tc->regmap, TSTCTL, val | ENI2CFILTER);
> > + if (ret) {
> > + dev_err(tc->dev, "failed to set TSTCTL\n");
> > + return ret;
> > + }
> > +
> > + ret = regmap_write(tc->regmap, SYSCTRL, DP0_VIDSRC_COLOR_BAR);
> > + if (ret) {
> > + dev_err(tc->dev, "failed to color bar video stream\n");
> > + return ret;
> > + }
> > + }
> > +
> > + return 0;
> > +}
> > +
> > +DEFINE_SIMPLE_ATTRIBUTE(tc_tstctl_fops, NULL, tc_tstctl_set, "%llu\n");
> > +
> > +static int tc_late_register(struct drm_connector *connector)
> > +{
> > + if (connector->debugfs_entry)
> > + debugfs_create_file_unsafe("tstctl", 0644,
> > + connector->debugfs_entry,
> > + connector_to_tc(connector),
> > + &tc_tstctl_fops);
> > + return 0;
> > +}
>
> I very recently wanted to add quick debugfs functionality to a bridge
> too, but as there didn't seem an easy way to do it, I just lazily added
> the debugfs files to the debugfs root...
>
> I'm not sure if adding bridge's debugfs files to connector's directory
> is a good idea. What if we have two bridges, both have the same debugfs
> file? Or even if there's no conflict, there's also no way to know which
> bridge a particular debugfs file belongs to.
>
> Maybe we need some DRM infrastructure for bridge debugfs?
>
I'll move to using a dedicated entry in debugfs, which should address
all of those concerns.
Thanks,
Andrey Smirnov
Powered by blists - more mailing lists