On 2024-08-28 09:58, Alex Deucher wrote:
> On Wed, Aug 28, 2024 at 9:53 AM Jani Nikula <jani.nikula@xxxxxxxxx> wrote:
>>
>> On Wed, 28 Aug 2024, Daniel Vetter <daniel.vetter@xxxxxxxx> wrote:
>>> On Mon, Aug 12, 2024 at 03:23:12PM +0300, Jani Nikula wrote:
>>>> Instead of just smashing jiffies into a GUID, use guid_gen() to generate
>>>> RFC 4122 compliant GUIDs.
>>>>
>>>> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx>
>>>>
>>>> ---
>>>>
>>>> Side note, it baffles me why amdgpu has a copy of this instead of
>>>> plumbing it into drm mst code.
>>>
>>> Yeah ec5fa9fcdeca ("drm/amd/display: Adjust the MST resume flow") promised
>>> a follow-up, but that seems to have never materialized. Really should
>>> materialize though. Patch lgtm
>>>
>>> Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
>>
>> Thanks!
>>
>> Cc: AMD folks, ack for merging the series via drm-misc-next?
>
> Unless Harry has any objections,
> Acked-by: Alex Deucher <alexander.deucher@xxxxxxx>
>
Acked-by: Harry Wentland <harry.wentland@xxxxxxx>
Harry
>>
>> BR,
>> Jani.
>>
>>
>>>
>>>
>>>> ---
>>>> .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c | 23 ++++++++++---------
>>>> 1 file changed, 12 insertions(+), 11 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 72c10fc2c890..ce05e7e2a383 100644
>>>> --- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>>>> +++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
>>>> @@ -2568,9 +2568,9 @@ static int dm_late_init(void *handle)
>>>>
>>>> static void resume_mst_branch_status(struct drm_dp_mst_topology_mgr *mgr)
>>>> {
>>>> + u8 buf[UUID_SIZE];
>>>> + guid_t guid;
>>>> int ret;
>>>> - u8 guid[16];
>>>> - u64 tmp64;
>>>>
>>>> mutex_lock(&mgr->lock);
>>>> if (!mgr->mst_primary)
>>>> @@ -2591,26 +2591,27 @@ static void resume_mst_branch_status(struct drm_dp_mst_topology_mgr *mgr)
>>>> }
>>>>
>>>> /* Some hubs forget their guids after they resume */
>>>> - ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
>>>> - if (ret != 16) {
>>>> + ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, buf, sizeof(buf));
>>>> + if (ret != sizeof(buf)) {
>>>> drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n");
>>>> goto out_fail;
>>>> }
>>>>
>>>> - if (memchr_inv(guid, 0, 16) == NULL) {
>>>> - tmp64 = get_jiffies_64();
>>>> - memcpy(&guid[0], &tmp64, sizeof(u64));
>>>> - memcpy(&guid[8], &tmp64, sizeof(u64));
>>>> + import_guid(&guid, buf);
>>>>
>>>> - ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, guid, 16);
>>>> + if (guid_is_null(&guid)) {
>>>> + guid_gen(&guid);
>>>> + export_guid(buf, &guid);
>>>>
>>>> - if (ret != 16) {
>>>> + ret = drm_dp_dpcd_write(mgr->aux, DP_GUID, buf, sizeof(buf));
>>>> +
>>>> + if (ret != sizeof(buf)) {
>>>> drm_dbg_kms(mgr->dev, "check mstb guid failed - undocked during suspend?\n");
>>>> goto out_fail;
>>>> }
>>>> }
>>>>
>>>> - import_guid(&mgr->mst_primary->guid, guid);
>>>> + guid_copy(&mgr->mst_primary->guid, &guid);
>>>>
>>>> out_fail:
>>>> mutex_unlock(&mgr->lock);
>>>> --
>>>> 2.39.2
>>>>
>>
>> --
>> Jani Nikula, Intel
