| 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: <1272fea64aa41a4c73a26fd0a51309a9acc03a8f.camel@gmail.com>
Date: Fri, 06 Feb 2026 21:46:14 +0100
From: Tomasz Pakuła <tomasz.pakula.oficjalny@...il.com>
To: Harry Wentland <harry.wentland@....com>, alexander.deucher@....com,
sunpeng.li@....com
Cc: maarten.lankhorst@...ux.intel.com, mripard@...nel.org,
tzimmermann@...e.de, airlied@...il.com, simona@...ll.ch,
siqueira@...lia.com, dri-devel@...ts.freedesktop.org,
amd-gfx@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
bernhard.berger@...il.com, michel.daenzer@...lbox.org,
daniel@...ishbar.org, admin@...1337.dev
Subject: Re: [PATCH v3 02/19] drm/amd/display: Refactor
amdgpu_dm_update_freesync_caps()
On Fri, 2026-02-06 at 13:22 -0500, Harry Wentland wrote:
>
> On 2026-02-03 13:56, Tomasz Pakuła wrote:
> > [Why]
> > This function started to get very messy and hard to follow.
> >
> > [How]
> > Eject some functionality to separate functions and simplify greatly.
> >
> > Changes in v3:
> > - Less struct traversal in helper functions
> >
> > Signed-off-by: Tomasz Pakuła <tomasz.pakula.oficjalny@...il.com>
> > ---
> > .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 123 +++++++++++-------
> > 1 file changed, 73 insertions(+), 50 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > index 29e4a047b455..2c5877ed5f32 100644
> > --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
> > @@ -13119,8 +13119,8 @@ static void parse_edid_displayid_vrr(struct drm_connector *connector,
> > }
> > }
> >
> > -static int parse_amd_vsdb(struct amdgpu_dm_connector *aconnector,
> > - const struct edid *edid, struct amdgpu_hdmi_vsdb_info *vsdb_info)
> > +static int parse_amd_vsdb_did(struct amdgpu_dm_connector *aconnector,
> > + const struct edid *edid, struct amdgpu_hdmi_vsdb_info *vsdb_info)
> > {
> > u8 *edid_ext = NULL;
> > int i;
> > @@ -13172,13 +13172,13 @@ static int parse_amd_vsdb(struct amdgpu_dm_connector *aconnector,
> > return false;
> > }
> >
> > -static int parse_hdmi_amd_vsdb(struct amdgpu_dm_connector *aconnector,
> > - const struct edid *edid,
> > - struct amdgpu_hdmi_vsdb_info *vsdb_info)
> > +static int parse_amd_vsdb_cea(struct amdgpu_dm_connector *aconnector,
> > + const struct edid *edid,
> > + struct amdgpu_hdmi_vsdb_info *vsdb_info)
> > {
> > + struct amdgpu_hdmi_vsdb_info vsdb_local = {0};
> > u8 *edid_ext = NULL;
> > int i;
> > - bool valid_vsdb_found = false;
> >
> > /*----- drm_find_cea_extension() -----*/
> > /* No EDID or EDID extensions */
> > @@ -13199,9 +13199,47 @@ static int parse_hdmi_amd_vsdb(struct amdgpu_dm_connector *aconnector,
> > if (edid_ext[0] != CEA_EXT)
> > return -ENODEV;
> >
> > - valid_vsdb_found = parse_edid_cea(aconnector, edid_ext, EDID_LENGTH, vsdb_info);
> > + if (!parse_edid_cea(aconnector, edid_ext, EDID_LENGTH, &vsdb_local))
> > + return -ENODEV;
> >
> > - return valid_vsdb_found ? i : -ENODEV;
> > + *vsdb_info = vsdb_local;
> > + return i;
> > +}
> > +
> > +static bool is_monitor_range_invalid(const struct drm_connector *conn)
> > +{
> > + return conn->display_info.monitor_range.min_vfreq == 0 ||
> > + conn->display_info.monitor_range.max_vfreq == 0;
> > +}
> > +
> > +/*
> > + * Returns true if (max_vfreq - min_vfreq) > 10
> > + */
> > +static bool is_freesync_capable(const struct drm_monitor_range_info *range)
> > +{
> > + return (range->max_vfreq - range->min_vfreq) > 10;
> > +}
> > +
> > +static void monitor_range_from_vsdb(struct drm_display_info *display,
> > + const struct amdgpu_hdmi_vsdb_info *vsdb)
> > +{
> > + display->monitor_range.min_vfreq = vsdb->min_refresh_rate_hz;
> > + display->monitor_range.max_vfreq = vsdb->max_refresh_rate_hz;
> > +}
> > +
> > +/*
> > + * Returns true if connector is capable of freesync
> > + * Optionally, can fetch the range from AMD vsdb
> > + */
> > +static bool copy_range_to_amdgpu_connector(struct drm_connector *conn)
> > +{
> > + struct amdgpu_dm_connector *aconn = to_amdgpu_dm_connector(conn);
> > + struct drm_monitor_range_info *range = &conn->display_info.monitor_range;
> > +
> > + aconn->min_vfreq = range->min_vfreq;
> > + aconn->max_vfreq = range->max_vfreq;
> > +
> > + return is_freesync_capable(range);
> > }
> >
> > /**
> > @@ -13218,13 +13256,14 @@ static int parse_hdmi_amd_vsdb(struct amdgpu_dm_connector *aconnector,
> > void amdgpu_dm_update_freesync_caps(struct drm_connector *connector,
> > const struct drm_edid *drm_edid)
> > {
> > - int i = 0;
> > struct amdgpu_dm_connector *amdgpu_dm_connector =
> > to_amdgpu_dm_connector(connector);
> > struct dm_connector_state *dm_con_state = NULL;
> > struct dc_sink *sink;
> > struct amdgpu_device *adev = drm_to_adev(connector->dev);
> > struct amdgpu_hdmi_vsdb_info vsdb_info = {0};
> > + struct amdgpu_hdmi_vsdb_info vsdb_did = {0};
> > + struct dpcd_caps dpcd_caps = {0};
> > const struct edid *edid;
> > bool freesync_capable = false;
> > enum adaptive_sync_type as_type = ADAPTIVE_SYNC_TYPE_NONE;
> > @@ -13256,62 +13295,46 @@ void amdgpu_dm_update_freesync_caps(struct drm_connector *connector,
> > goto update;
> >
> > edid = drm_edid_raw(drm_edid); // FIXME: Get rid of drm_edid_raw()
> > + parse_amd_vsdb_cea(amdgpu_dm_connector, edid, &vsdb_info);
>
> This change says it's a refactor, which in my book should
> never include a (subtle) functional change. But we're now
> calling this function for all sink_signal types, whereas
> before it was only called for HDMI_TYPE_A.
Got it. I'll explain it better in the next version. I think the edid
check was there only to guard against parsing it in parse_amd_vsdb(). I
must say the code there was not the clearest but I can't think of a
reason to check for edid in case of DP. If it's missing, the
display_info won't have a valid range.
The parsing functions check for edid as well so this check is actually
redundant and could be entirely removed. vsdb structs are initialized to
0 either way so nothing will break and nothing will get enabled by
mistake.
Quite honestly, looking at (before changes) parse_edid_displayid_vrr(),
parse_amd_vsdb(), parse_hdmi_amd_vsdb() there's quite a bit of code
duplication and especially the former two are almost the same.
> > +
> > + if (amdgpu_dm_connector->dc_link)
> > + dpcd_caps = amdgpu_dm_connector->dc_link->dpcd_caps;
> >
> > /* Some eDP panels only have the refresh rate range info in DisplayID */
> > - if ((connector->display_info.monitor_range.min_vfreq == 0 ||
> > - connector->display_info.monitor_range.max_vfreq == 0))
> > + if (is_monitor_range_invalid(connector))
> > parse_edid_displayid_vrr(connector, edid);
> >
> > - if (edid && (sink->sink_signal == SIGNAL_TYPE_DISPLAY_PORT ||
> > - sink->sink_signal == SIGNAL_TYPE_EDP)) {
> > - if (amdgpu_dm_connector->dc_link &&
> > - amdgpu_dm_connector->dc_link->dpcd_caps.allow_invalid_MSA_timing_param) {
> > - amdgpu_dm_connector->min_vfreq = connector->display_info.monitor_range.min_vfreq;
> > - amdgpu_dm_connector->max_vfreq = connector->display_info.monitor_range.max_vfreq;
> > - if (amdgpu_dm_connector->max_vfreq - amdgpu_dm_connector->min_vfreq > 10)
> > - freesync_capable = true;
> > - }
> > + if (sink->sink_signal == SIGNAL_TYPE_DISPLAY_PORT ||
> > + sink->sink_signal == SIGNAL_TYPE_EDP) {
> >
> > - parse_amd_vsdb(amdgpu_dm_connector, edid, &vsdb_info);
> > + if (dpcd_caps.allow_invalid_MSA_timing_param)
> > + freesync_capable = copy_range_to_amdgpu_connector(connector);
> >
> > - if (vsdb_info.replay_mode) {
> > - amdgpu_dm_connector->vsdb_info.replay_mode = vsdb_info.replay_mode;
> > - amdgpu_dm_connector->vsdb_info.amd_vsdb_version = vsdb_info.amd_vsdb_version;
> > + /* eDP */
> > + if (edid)
>
> Same here, I'm not entirely sure whether moving the edid
> check down here won't have a subtle behavior change.
>
> I'd like to be either convinced that these things cannot
> change behavior, or I'd like to see this broken out into
> two patches, (1) a true refactor patch, without possible
> behavior changes, and (2) another patch that might affect
> behavior.
Will do. Now that I'm looking at this with a clear head, it's too much
in one go even for me :) I think this will end up as 3-4 patches to
clean up the vsdb parsing functions as well.
>
> Overall I'm in favor of the changes and thank you for
> cleaning this up. I'm just worried about subtle bugs.
>
> Harry
>
> > + parse_amd_vsdb_did(amdgpu_dm_connector, edid, &vsdb_did);
> > +
> > + if (vsdb_did.replay_mode) {
> > + amdgpu_dm_connector->vsdb_info.replay_mode = vsdb_did.replay_mode;
> > + amdgpu_dm_connector->vsdb_info.amd_vsdb_version = vsdb_did.amd_vsdb_version;
> > amdgpu_dm_connector->as_type = ADAPTIVE_SYNC_TYPE_EDP;
> > }
> >
> > - } else if (drm_edid && sink->sink_signal == SIGNAL_TYPE_HDMI_TYPE_A) {
> > - i = parse_hdmi_amd_vsdb(amdgpu_dm_connector, edid, &vsdb_info);
> > - if (i >= 0 && vsdb_info.freesync_supported) {
> > - amdgpu_dm_connector->min_vfreq = vsdb_info.min_refresh_rate_hz;
> > - amdgpu_dm_connector->max_vfreq = vsdb_info.max_refresh_rate_hz;
> > - if (amdgpu_dm_connector->max_vfreq - amdgpu_dm_connector->min_vfreq > 10)
> > - freesync_capable = true;
> > -
> > - connector->display_info.monitor_range.min_vfreq = vsdb_info.min_refresh_rate_hz;
> > - connector->display_info.monitor_range.max_vfreq = vsdb_info.max_refresh_rate_hz;
> > - }
> > + } else if (sink->sink_signal == SIGNAL_TYPE_HDMI_TYPE_A && vsdb_info.freesync_supported) {
> > + monitor_range_from_vsdb(&connector->display_info, &vsdb_info);
> > + freesync_capable = copy_range_to_amdgpu_connector(connector);
> > }
> >
> > if (amdgpu_dm_connector->dc_link)
> > as_type = dm_get_adaptive_sync_support_type(amdgpu_dm_connector->dc_link);
> >
> > - if (as_type == FREESYNC_TYPE_PCON_IN_WHITELIST) {
> > - i = parse_hdmi_amd_vsdb(amdgpu_dm_connector, edid, &vsdb_info);
> > - if (i >= 0 && vsdb_info.freesync_supported && vsdb_info.amd_vsdb_version > 0) {
> > + if (as_type == FREESYNC_TYPE_PCON_IN_WHITELIST && vsdb_info.freesync_supported) {
> > + amdgpu_dm_connector->pack_sdp_v1_3 = true;
> > + amdgpu_dm_connector->as_type = as_type;
> > + amdgpu_dm_connector->vsdb_info = vsdb_info;
> >
> > - amdgpu_dm_connector->pack_sdp_v1_3 = true;
> > - amdgpu_dm_connector->as_type = as_type;
> > - amdgpu_dm_connector->vsdb_info = vsdb_info;
> > -
> > - amdgpu_dm_connector->min_vfreq = vsdb_info.min_refresh_rate_hz;
> > - amdgpu_dm_connector->max_vfreq = vsdb_info.max_refresh_rate_hz;
> > - if (amdgpu_dm_connector->max_vfreq - amdgpu_dm_connector->min_vfreq > 10)
> > - freesync_capable = true;
> > -
> > - connector->display_info.monitor_range.min_vfreq = vsdb_info.min_refresh_rate_hz;
> > - connector->display_info.monitor_range.max_vfreq = vsdb_info.max_refresh_rate_hz;
> > - }
> > + monitor_range_from_vsdb(&connector->display_info, &vsdb_info);
> > + freesync_capable = copy_range_to_amdgpu_connector(connector);
> > }
> >
> > update:
>
Powered by blists - more mailing lists