On 09/09/16 13:20, Deucher, Alexander wrote: >> -----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 at vger.kernel.org; dri- >> devel at lists.freedesktop.org >> 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
Thanks Alex, I look forward to hearing from you when you have finished recovering from your holiday and the associated work backlog :). I raised a bug (https://bugs.freedesktop.org/show_bug.cgi?id=97637) - probably on the wrong component but fixing that should be easy. It has a more complete copy of the Opps. Regards Mark. > >> >> 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 at thurning-instruments.co.uk> >>>>>>> Tested-by: Mark Fortescue <mark at thurning-instruments.co.uk> >>>>>>> >>>>>>> --- >>>>>>> >>>>>>> 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 at lists.freedesktop.org >>>>>>> https://lists.freedesktop.org/mailman/listinfo/dri-devel >>>>>> >>> _______________________________________________ >>> dri-devel mailing list >>> dri-devel at lists.freedesktop.org >>> https://lists.freedesktop.org/mailman/listinfo/dri-devel >> >
