> -----Original Message----- > From: Koenig, Christian > Sent: Friday, September 09, 2016 4:16 AM > To: Mark Fortescue; Koenig, Christian; David Airlie > Cc: Deucher, Alexander; linux-kernel@xxxxxxxxxxxxxxx; dri- > devel@xxxxxxxxxxxxxxxxxxxxx > Subject: Re: [PATCH 001/001] drivers/gpu/radeon: NULL pointer deference > workaround > > >> On this motherboard, DP-1 is a single channel 18bit LVDS LCD panel > >> interface and DP-2 is a DVI interface (which I can connect to my > >> monitor if testing this is useful). There are no displayport connectors. > > > > Yeah, but from the driver point of view there are only DP connectors on > > the chip. The LVDS and DVI are probably realized with external DP to > > whatever converter ICs. > > > > > > That would explain why some similar boards have 24bit LVDS and others > > only 18bit LVDS. > > It could be that this is actually a configuration we don't support yet > with radeon and/or the display stack. > > E.g. that the connector only uses the displayport LVDS lanes, but not > actual the displayport protocol to train those lanes. > > Instead it rather expects a fixed training which is configured somewhere > in the BIOS. > > Anyway Alex needs to take a look, he knows displayport much better than > I do (and hates it passionately :). Generally these sorts of setups are supported by exposing an LVDS or eDP connector rather than a regular DP. In the case of LVDS and eDP, we have code to fallback to a hardcoded EDID in the vbios if DDC is not available. I'll take a closer look when I'm back. Alex > > Cheers, > Christian. > > Am 08.09.2016 um 13:18 schrieb Mark Fortescue: > > On 08/09/16 11:25, Christian König wrote: > >> Am 08.09.2016 um 11:09 schrieb Mark Fortescue: > >>> Hi Christian, > >>> > >>> Thank you for the feedback. > >>> > >>> On 08/09/16 08:14, Christian König wrote: > >>>> Am 07.09.2016 um 19:38 schrieb Mark Fortescue: > >>>>> > >>>>> On an LV-683 (AMD Dual-core G-T56N) Mini-ITX board, I get a Kernel > >>>>> Oops because Connector 0 (LCD Panel interface) does not have DDC. > >>>> > >>>> I'm not an expert on this, but that is really odd cause even LCD > >>>> Panels > >>>> should have a DDC interface. > >>>> > >>>>> > >>>>> Ubuntu 16.04 LTS Kernel (4.4 series): > >>>>> > >>>>> ... > >>>>> [ 8.262990] [drm] ib test on ring 5 succeeded > >>>>> [ 8.288897] [drm] Radeon Display Connectors > >>>>> [ 8.293175] [drm] Connector 0: > >>>>> [ 8.296252] [drm] DP-1 > >>>> > >>>> Especially since the BIOS claims that this is a displayport connector > >>>> and there is no physical way to have a DP without an DDC as far as I > >>>> know. > >>>> > >>>> Please open a bug report on FDO and attach you BIOS image. > >>> > >>> FDO ? I am not familiar with this. Please can you enlighten me. > >>> > >> > >> See here: http://bugs.freedesktop.org/ > >> > >>> I do not have a BIOS image so will need some assistance in > >>> understanding what is required here and how I extract the BIOS > >>> information you are after. > >>> > >> > >> Sorry my fault. Mullins is an APU, so you don't have a dedicated video > >> BIOS. As usually I didn't got enough sleep :) But please open up a bug > >> report anyway. > > > > Know the problem of being awake too long :). I will raise a bug. > > > >> > >>> On this motherboard, DP-1 is a single channel 18bit LVDS LCD panel > >>> interface and DP-2 is a DVI interface (which I can connect to my > >>> monitor if testing this is useful). There are no displayport > >>> connectors. > >> > >> Yeah, but from the driver point of view there are only DP connectors on > >> the chip. The LVDS and DVI are probably realized with external DP to > >> whatever converter ICs. > >> > > > > That would explain why some similar boards have 24bit LVDS and others > > only 18bit LVDS. > > > >>> > >>> On industrial motherboards, I have noticed that it is not uncommon to > >>> hard code the information for the LCD panel into the BIOS so no DDC is > >>> required. In this case, there is no LCD panel connected to the > >>> interface anyway. > >>> > >> > >> That is correct and as far as I know well supported by Radeon, but the > >> crux is there should still be a DDC channel even if there isn't anything > >> attached to it. > >> > >> See with displayport you got four LVDS channels to submit the actual > >> picture and an AUX channel to configure and query the device. The DDC is > >> just represented as certain packets over the AUX channel. > >> > >> If the AUX channel doesn't work or isn't connect then the link training > >> wouldn't be possible as well and so you wouldn't be able to get any > >> picture on the LVDS. > >> > > > > Interesting. > > > >>> See http://www.commell.com.tw/product/SBC/LV-683.HTM for more > >>> information on the board. Looking at the web site, there is a BIOS > >>> image available form Commell if that is of use. > >> > >> Alex clearly needs to take a look on this. I think for the time being > >> you could hack together a patch which just ignores DP connectors during > >> probing if they don't have an associated DDC instead of changing the > >> code everywhere the DDC object is required. > >> > > > > I will try to find the time to look at this in more detail. GPU/DRM is > > not something I have done any real work on in the past so I do not > > know how it all fits together. The overkill on the code changes is the > > result, as that way I don't need to understand where and why the > > helper function (radeon_dp_getsinktype) gets called or what other code > > paths can be executed that could fail. > > > > I will wait for Alex to have a think about it and respond before I do > > any more - that way I can finish the work I am paid to do first :). > > > >> Regards, > >> Christian. > >> > > Regards > > Mark. > >>> > >>>> > >>>> Alex can probably take a look when he's back from vacation. > >>>> > >>>> Regards, > >>>> Christian. > >>>> > >>>>> [ 8.298791] [drm] Encoders: > >>>>> [ 8.301770] [drm] DFP1: INTERNAL_UNIPHY > >>>>> [ 8.305973] [drm] Connector 1: > >>>>> [ 8.309043] [drm] DP-2 > >>>>> [ 8.311598] [drm] HPD2 > >>>>> [ 8.314169] [drm] DDC: 0x6440 0x6440 0x6444 0x6444 0x6448 0x6448 > >>>>> 0x644c 0x644c > >>>>> [ 8.321609] [drm] Encoders: > >>>>> [ 8.324589] [drm] DFP2: INTERNAL_UNIPHY > >>>>> [ 8.328793] [drm] Connector 2: > >>>>> [ 8.331856] [drm] VGA-1 > >>>>> [ 8.342947] [drm] DDC: 0x64d8 0x64d8 0x64dc 0x64dc 0x64e0 0x64e0 > >>>>> 0x64e4 0x64e4 > >>>>> [ 8.350341] [drm] Encoders: > >>>>> [ 8.353310] [drm] CRT1: INTERNAL_KLDSCP_DAC1 > >>>>> [ 8.358195] BUG: unable to handle kernel NULL pointer dereference at > >>>>> 0000000000000409 > >>>>> [ 8.409733] [<ffffffffc02024da>] radeon_dp_getsinktype+0x1a/0x30 > >>>>> [radeon] > >>>>> [ 8.416805] PGD 0 > >>>>> [ 8.418841] Oops: 0000 [#1] SMP > >>>>> ... > >>>>> > >>>>> This patch prevents Kernel failures due to a connector not having a > >>>>> DDC interface by changing the code so that ddc_bus is always checked > >>>>> before use. > >>>>> The problem was first identified using the uBuntu MATE 14.04 LTS > >>>>> (3.16 > >>>>> series kernels) but not dealt with at that time. On attempting to > >>>>> install uBuntu MATE 16.04 LTS (4.4 series kernels), it became clear > >>>>> that using various workarounds to allow the issue to be ignored were > >>>>> not viable so more effort was put in to sorting the issue > >>>>> resulting in > >>>>> this patch. See https://bugs.launchpad.net/bugs/1587885 for more > >>>>> details. > >>>>> > >>>>> Signed-off-by: Mark Fortescue <mark@xxxxxxxxxxxxxxxxxxxxxxxxxx> > >>>>> Tested-by: Mark Fortescue <mark@xxxxxxxxxxxxxxxxxxxxxxxxxx> > >>>>> > >>>>> --- > >>>>> > >>>>> Looks like Thunderbird may have made a mess of the patch when > pasting > >>>>> the contents into the mail message - my alternate mail client (pine) > >>>>> also has strict line length handling and trashes non-MIME encoded > >>>>> patches. > >>>>> > >>>>> This may not be the correct approach to solving the issue but it is > >>>>> clean in that it ensures that ddc_bus is never used when NULL > >>>>> regardless of how the code ended up at the point of use. > >>>>> > >>>>> If it helps with back porting, I have patches for the uBuntu 14.04 > >>>>> LTS > >>>>> [3.13 series], uBuntu MATE 14.04 LTS [3.16 series] and uBuntu 16.04 > >>>>> LTS [4.4 series] kernels. > >>>>> > >>>>> Test Hardware: > >>>>> Commell LV-683 Mini-ITX with onboard AMD Dual-core G-T56N > >>>>> 4G Ram, 2x1TB Disk, HANNS-G HC194D 1280x1024 LCD (VGA). > >>>>> 4.8.0-rc5 with patch boots without error. > >>>>> > >>>>> drivers/gpu/drm/radeon/atombios_dp.c | 60 > >>>>> ++++++++++++------- > >>>>> drivers/gpu/drm/radeon/radeon_connectors.c | 46 +++++++------- > >>>>> drivers/gpu/drm/radeon/radeon_dp_mst.c | 9 ++ > >>>>> drivers/gpu/drm/radeon/radeon_i2c.c | 3 > >>>>> 4 files changed, 73 insertions(+), 45 deletions(-) > >>>>> > >>>>> Patch: > >>>>> diff --git a/drivers/gpu/drm/radeon/atombios_dp.c > >>>>> b/drivers/gpu/drm/radeon/atombios_dp.c > >>>>> index cead089a..98b3c0e 100644 > >>>>> --- a/drivers/gpu/drm/radeon/atombios_dp.c > >>>>> +++ b/drivers/gpu/drm/radeon/atombios_dp.c > >>>>> @@ -232,6 +232,9 @@ void radeon_dp_aux_init(struct > radeon_connector > >>>>> *radeon_connector) > >>>>> struct radeon_device *rdev = dev->dev_private; > >>>>> int ret; > >>>>> > >>>>> + if (!radeon_connector->ddc_bus) > >>>>> + return; > >>>>> + > >>>>> radeon_connector->ddc_bus->rec.hpd = radeon_connector- > >hpd.hpd; > >>>>> radeon_connector->ddc_bus->aux.dev = > >>>>> radeon_connector->base.kdev; > >>>>> if (ASIC_IS_DCE5(rdev)) { > >>>>> @@ -364,6 +367,9 @@ u8 radeon_dp_getsinktype(struct > radeon_connector > >>>>> *radeon_connector) > >>>>> struct drm_device *dev = radeon_connector->base.dev; > >>>>> struct radeon_device *rdev = dev->dev_private; > >>>>> > >>>>> + if (!radeon_connector->ddc_bus) > >>>>> + return 0; > >>>>> + > >>>>> return radeon_dp_encoder_service(rdev, > >>>>> ATOM_DP_ACTION_GET_SINK_TYPE, 0, > >>>>> radeon_connector->ddc_bus->rec.i2c_id, 0); > >>>>> } > >>>>> @@ -376,6 +382,9 @@ static void radeon_dp_probe_oui(struct > >>>>> radeon_connector *radeon_connector) > >>>>> if (!(dig_connector->dpcd[DP_DOWN_STREAM_PORT_COUNT] & > >>>>> DP_OUI_SUPPORT)) > >>>>> return; > >>>>> > >>>>> + if (!radeon_connector->ddc_bus) > >>>>> + return; > >>>>> + > >>>>> if (drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, > >>>>> DP_SINK_OUI, buf, 3) == 3) > >>>>> DRM_DEBUG_KMS("Sink OUI: %02hx%02hx%02hx\n", > >>>>> buf[0], buf[1], buf[2]); > >>>>> @@ -391,6 +400,9 @@ bool radeon_dp_getdpcd(struct > radeon_connector > >>>>> *radeon_connector) > >>>>> u8 msg[DP_DPCD_SIZE]; > >>>>> int ret, i; > >>>>> > >>>>> + if (!radeon_connector->ddc_bus) > >>>>> + return false; > >>>>> + > >>>>> for (i = 0; i < 7; i++) { > >>>>> ret = drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, > >>>>> DP_DPCD_REV, msg, > >>>>> DP_DPCD_SIZE); > >>>>> @@ -428,24 +440,26 @@ int radeon_dp_get_panel_mode(struct > drm_encoder > >>>>> *encoder, > >>>>> > >>>>> dig_connector = radeon_connector->con_priv; > >>>>> > >>>>> - if (dp_bridge != ENCODER_OBJECT_ID_NONE) { > >>>>> - /* DP bridge chips */ > >>>>> - if (drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux, > >>>>> - DP_EDP_CONFIGURATION_CAP, &tmp) == 1) { > >>>>> - if (tmp & 1) > >>>>> - panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE; > >>>>> - else if ((dp_bridge == ENCODER_OBJECT_ID_NUTMEG) || > >>>>> - (dp_bridge == ENCODER_OBJECT_ID_TRAVIS)) > >>>>> - panel_mode = DP_PANEL_MODE_INTERNAL_DP1_MODE; > >>>>> - else > >>>>> - panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE; > >>>>> - } > >>>>> - } else if (connector->connector_type == > >>>>> DRM_MODE_CONNECTOR_eDP) { > >>>>> - /* eDP */ > >>>>> - if (drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux, > >>>>> - DP_EDP_CONFIGURATION_CAP, &tmp) == 1) { > >>>>> - if (tmp & 1) > >>>>> - panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE; > >>>>> + if (radeon_connector->ddc_bus) { > >>>>> + if (dp_bridge != ENCODER_OBJECT_ID_NONE) { > >>>>> + /* DP bridge chips */ > >>>>> + if (drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux, > >>>>> + DP_EDP_CONFIGURATION_CAP, &tmp) == 1) { > >>>>> + if (tmp & 1) > >>>>> + panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE; > >>>>> + else if ((dp_bridge == ENCODER_OBJECT_ID_NUTMEG) || > >>>>> + (dp_bridge == ENCODER_OBJECT_ID_TRAVIS)) > >>>>> + panel_mode = DP_PANEL_MODE_INTERNAL_DP1_MODE; > >>>>> + else > >>>>> + panel_mode = DP_PANEL_MODE_EXTERNAL_DP_MODE; > >>>>> + } > >>>>> + } else if (connector->connector_type == > >>>>> DRM_MODE_CONNECTOR_eDP) { > >>>>> + /* eDP */ > >>>>> + if (drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux, > >>>>> + DP_EDP_CONFIGURATION_CAP, &tmp) == 1) { > >>>>> + if (tmp & 1) > >>>>> + panel_mode = DP_PANEL_MODE_INTERNAL_DP2_MODE; > >>>>> + } > >>>>> } > >>>>> } > >>>>> > >>>>> @@ -511,6 +525,9 @@ bool radeon_dp_needs_link_train(struct > >>>>> radeon_connector *radeon_connector) > >>>>> u8 link_status[DP_LINK_STATUS_SIZE]; > >>>>> struct radeon_connector_atom_dig *dig = > >>>>> radeon_connector->con_priv; > >>>>> > >>>>> + if (!radeon_connector->ddc_bus) > >>>>> + return false; > >>>>> + > >>>>> if > >>>>> (drm_dp_dpcd_read_link_status(&radeon_connector->ddc_bus- > >aux, > >>>>> link_status) > >>>>> <= 0) > >>>>> return false; > >>>>> @@ -531,7 +548,7 @@ void radeon_dp_set_rx_power_state(struct > >>>>> drm_connector *connector, > >>>>> dig_connector = radeon_connector->con_priv; > >>>>> > >>>>> /* power up/down the sink */ > >>>>> - if (dig_connector->dpcd[0] >= 0x11) { > >>>>> + if (radeon_connector->ddc_bus && dig_connector->dpcd[0] >= > >>>>> 0x11) { > >>>>> drm_dp_dpcd_writeb(&radeon_connector->ddc_bus->aux, > >>>>> DP_SET_POWER, power_state); > >>>>> usleep_range(1000, 2000); > >>>>> @@ -834,7 +851,8 @@ void radeon_dp_link_train(struct > drm_encoder > >>>>> *encoder, > >>>>> else > >>>>> dp_info.enc_id |= ATOM_DP_CONFIG_LINK_A; > >>>>> > >>>>> - if (drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux, > >>>>> DP_MAX_LANE_COUNT, &tmp) > >>>>> + if (radeon_connector->ddc_bus && > >>>>> + drm_dp_dpcd_readb(&radeon_connector->ddc_bus->aux, > >>>>> DP_MAX_LANE_COUNT, &tmp) > >>>>> == 1) { > >>>>> if (ASIC_IS_DCE5(rdev) && (tmp & DP_TPS3_SUPPORTED)) > >>>>> dp_info.tp3_supported = true; > >>>>> @@ -850,7 +868,7 @@ void radeon_dp_link_train(struct > drm_encoder > >>>>> *encoder, > >>>>> dp_info.connector = connector; > >>>>> dp_info.dp_lane_count = dig_connector->dp_lane_count; > >>>>> dp_info.dp_clock = dig_connector->dp_clock; > >>>>> - dp_info.aux = &radeon_connector->ddc_bus->aux; > >>>>> + dp_info.aux = radeon_connector->ddc_bus ? > >>>>> &radeon_connector->ddc_bus->aux : 0; > >>>>> > >>>>> if (radeon_dp_link_train_init(&dp_info)) > >>>>> goto done; > >>>>> diff --git a/drivers/gpu/drm/radeon/radeon_connectors.c > >>>>> b/drivers/gpu/drm/radeon/radeon_connectors.c > >>>>> index b79f3b0..cec30c9 100644 > >>>>> --- a/drivers/gpu/drm/radeon/radeon_connectors.c > >>>>> +++ b/drivers/gpu/drm/radeon/radeon_connectors.c > >>>>> @@ -328,31 +328,32 @@ static void > radeon_connector_get_edid(struct > >>>>> drm_connector *connector) > >>>>> if (radeon_connector->router.ddc_valid) > >>>>> radeon_router_select_ddc_port(radeon_connector); > >>>>> > >>>>> - if > >>>>> > ((radeon_connector_encoder_get_dp_bridge_encoder_id(connector) != > >>>>> - ENCODER_OBJECT_ID_NONE) && > >>>>> - radeon_connector->ddc_bus->has_aux) { > >>>>> - radeon_connector->edid = drm_get_edid(connector, > >>>>> - &radeon_connector->ddc_bus->aux.ddc); > >>>>> - } else if ((connector->connector_type == > >>>>> DRM_MODE_CONNECTOR_DisplayPort) || > >>>>> - (connector->connector_type == > DRM_MODE_CONNECTOR_eDP)) { > >>>>> - struct radeon_connector_atom_dig *dig = > >>>>> radeon_connector->con_priv; > >>>>> - > >>>>> - if ((dig->dp_sink_type == > CONNECTOR_OBJECT_ID_DISPLAYPORT || > >>>>> - dig->dp_sink_type == CONNECTOR_OBJECT_ID_eDP) && > >>>>> - radeon_connector->ddc_bus->has_aux) > >>>>> - radeon_connector->edid = > >>>>> drm_get_edid(&radeon_connector->base, > >>>>> + if (radeon_connector->ddc_bus) { > >>>>> + if > >>>>> > ((radeon_connector_encoder_get_dp_bridge_encoder_id(connector) != > >>>>> + ENCODER_OBJECT_ID_NONE) && > >>>>> + radeon_connector->ddc_bus->has_aux) { > >>>>> + radeon_connector->edid = drm_get_edid(connector, > >>>>> &radeon_connector->ddc_bus->aux.ddc); > >>>>> - else if (radeon_connector->ddc_bus) > >>>>> + } else if ((connector->connector_type == > >>>>> DRM_MODE_CONNECTOR_DisplayPort) || > >>>>> + (connector->connector_type == > >>>>> DRM_MODE_CONNECTOR_eDP)) { > >>>>> + struct radeon_connector_atom_dig *dig = > >>>>> radeon_connector->con_priv; > >>>>> + > >>>>> + if ((dig->dp_sink_type == > >>>>> CONNECTOR_OBJECT_ID_DISPLAYPORT || > >>>>> + dig->dp_sink_type == CONNECTOR_OBJECT_ID_eDP) && > >>>>> + radeon_connector->ddc_bus->has_aux) > >>>>> + radeon_connector->edid = > >>>>> drm_get_edid(&radeon_connector->base, > >>>>> + &radeon_connector->ddc_bus->aux.ddc); > >>>>> + else > >>>>> + radeon_connector->edid = > >>>>> drm_get_edid(&radeon_connector->base, > >>>>> + &radeon_connector->ddc_bus->adapter); > >>>>> + } else if (vga_switcheroo_handler_flags() & > >>>>> VGA_SWITCHEROO_CAN_SWITCH_DDC && > >>>>> + connector->connector_type == > >>>>> DRM_MODE_CONNECTOR_LVDS) { > >>>>> + radeon_connector->edid = > >>>>> drm_get_edid_switcheroo(&radeon_connector->base, > >>>>> + &radeon_connector->ddc_bus->adapter); > >>>>> + } else { > >>>>> radeon_connector->edid = > >>>>> drm_get_edid(&radeon_connector->base, > >>>>> &radeon_connector->ddc_bus->adapter); > >>>>> - } else if (vga_switcheroo_handler_flags() & > >>>>> VGA_SWITCHEROO_CAN_SWITCH_DDC && > >>>>> - connector->connector_type == > DRM_MODE_CONNECTOR_LVDS && > >>>>> - radeon_connector->ddc_bus) { > >>>>> - radeon_connector->edid = > >>>>> drm_get_edid_switcheroo(&radeon_connector->base, > >>>>> - &radeon_connector->ddc_bus->adapter); > >>>>> - } else if (radeon_connector->ddc_bus) { > >>>>> - radeon_connector->edid = > >>>>> drm_get_edid(&radeon_connector->base, > >>>>> - &radeon_connector->ddc_bus->adapter); > >>>>> + } > >>>>> } > >>>>> > >>>>> if (!radeon_connector->edid) { > >>>>> @@ -1312,6 +1313,7 @@ radeon_dvi_detect(struct drm_connector > >>>>> *connector, bool force) > >>>>> continue; > >>>>> list_radeon_connector = > >>>>> to_radeon_connector(list_connector); > >>>>> if (list_radeon_connector->shared_ddc && > >>>>> + radeon_connector->ddc_bus && > >>>>> (list_radeon_connector->ddc_bus->rec.i2c_id == > >>>>> radeon_connector->ddc_bus->rec.i2c_id)) { > >>>>> /* cases where both connectors are > >>>>> digital */ > >>>>> diff --git a/drivers/gpu/drm/radeon/radeon_dp_mst.c > >>>>> b/drivers/gpu/drm/radeon/radeon_dp_mst.c > >>>>> index de504ea..89e91f3 100644 > >>>>> --- a/drivers/gpu/drm/radeon/radeon_dp_mst.c > >>>>> +++ b/drivers/gpu/drm/radeon/radeon_dp_mst.c > >>>>> @@ -661,7 +661,7 @@ radeon_dp_mst_init(struct radeon_connector > >>>>> *radeon_connector) > >>>>> { > >>>>> struct drm_device *dev = radeon_connector->base.dev; > >>>>> > >>>>> - if (!radeon_connector->ddc_bus->has_aux) > >>>>> + if (!radeon_connector->ddc_bus || > >>>>> !radeon_connector->ddc_bus->has_aux) > >>>>> return 0; > >>>>> > >>>>> radeon_connector->mst_mgr.cbs = &mst_cbs; > >>>>> @@ -688,6 +688,9 @@ radeon_dp_mst_probe(struct > radeon_connector > >>>>> *radeon_connector) > >>>>> if (dig_connector->dpcd[DP_DPCD_REV] < 0x12) > >>>>> return 0; > >>>>> > >>>>> + if (!radeon_connector->ddc_bus || > >>>>> !radeon_connector->ddc_bus->has_aux) > >>>>> + return 0; > >>>>> + > >>>>> ret = drm_dp_dpcd_read(&radeon_connector->ddc_bus->aux, > >>>>> DP_MSTM_CAP, msg, > >>>>> 1); > >>>>> if (ret) { > >>>>> @@ -711,7 +714,9 @@ radeon_dp_mst_check_status(struct > >>>>> radeon_connector > >>>>> *radeon_connector) > >>>>> struct radeon_connector_atom_dig *dig_connector = > >>>>> radeon_connector->con_priv; > >>>>> int retry; > >>>>> > >>>>> - if (dig_connector->is_mst) { > >>>>> + if (dig_connector->is_mst && > >>>>> + radeon_connector->ddc_bus && > >>>>> + radeon_connector->ddc_bus->has_aux) { > >>>>> u8 esi[16] = { 0 }; > >>>>> int dret; > >>>>> int ret = 0; > >>>>> diff --git a/drivers/gpu/drm/radeon/radeon_i2c.c > >>>>> b/drivers/gpu/drm/radeon/radeon_i2c.c > >>>>> index 9590bcd..c18f7ba 100644 > >>>>> --- a/drivers/gpu/drm/radeon/radeon_i2c.c > >>>>> +++ b/drivers/gpu/drm/radeon/radeon_i2c.c > >>>>> @@ -63,6 +63,9 @@ bool radeon_ddc_probe(struct > radeon_connector > >>>>> *radeon_connector, bool use_aux) > >>>>> if (radeon_connector->router.ddc_valid) > >>>>> radeon_router_select_ddc_port(radeon_connector); > >>>>> > >>>>> + if (!radeon_connector->ddc_bus) > >>>>> + return false; > >>>>> + > >>>>> if (use_aux) { > >>>>> ret = i2c_transfer(&radeon_connector->ddc_bus->aux.ddc, > >>>>> msgs, 2); > >>>>> } else { > >>>>> _______________________________________________ > >>>>> dri-devel mailing list > >>>>> dri-devel@xxxxxxxxxxxxxxxxxxxxx > >>>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel > >>>> > > _______________________________________________ > > dri-devel mailing list > > dri-devel@xxxxxxxxxxxxxxxxxxxxx > > https://lists.freedesktop.org/mailman/listinfo/dri-devel > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
