Public bug reported: [Impact] WD19TB would report the number of lane(2-lane) and it works well on Type-C port of TGL platform. Change the LTTPR mode to non-transparent mode, WD19TB would report the larger number of lane(4-lane). It's over the type-c port's bandwidth.
[Fix] The patch is provided by Imre(https://patchwork.freedesktop.org/series/86267/). Calculate the PBN divider value based on the rate and lane count link parameters that the driver uses for all other computation. [Test Case] 1. Connected the WD19TB with the TGL platform's Type-C port and connected the external monitor on WD19TB with HDMI/Displayport. 2. Cold boot the TGL platform. 4. Check the monitor can be blinked and the video can output to the monitor. [Where problems could occur] It's more reasonable to calculate the PBN divider based on the source's rate and lane count, not the mst's capability. ** Affects: linux (Ubuntu) Importance: Undecided Assignee: koba (kobako) Status: In Progress ** Affects: linux-oem-5.10 (Ubuntu) Importance: Undecided Status: New ** Affects: linux (Ubuntu Focal) Importance: Undecided Status: New ** Affects: linux-oem-5.10 (Ubuntu Focal) Importance: Undecided Assignee: koba (kobako) Status: In Progress ** Affects: linux (Ubuntu Hirsute) Importance: Undecided Assignee: koba (kobako) Status: In Progress ** Affects: linux-oem-5.10 (Ubuntu Hirsute) Importance: Undecided Status: New ** Also affects: linux-oem-5.10 (Ubuntu) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Hirsute) Importance: Undecided Status: New ** Also affects: linux-oem-5.10 (Ubuntu Hirsute) Importance: Undecided Status: New ** Also affects: linux (Ubuntu Focal) Importance: Undecided Status: New ** Also affects: linux-oem-5.10 (Ubuntu Focal) Importance: Undecided Status: New ** Changed in: linux (Ubuntu Hirsute) Assignee: (unassigned) => koba (kobako) ** Changed in: linux (Ubuntu Hirsute) Status: New => In Progress ** Changed in: linux-oem-5.10 (Ubuntu Focal) Status: New => In Progress ** Changed in: linux-oem-5.10 (Ubuntu Focal) Assignee: (unassigned) => koba (kobako) ** Description changed: [Impact] WD19TB would report the number of lane(2-lane) and it works well on Type-C port of TGL platform. - Change the LTTPR mode to non-transparent mode, WD19TB would report the larger number of lane(4-lane). It's over the type-c port's bandwidth. + Change the LTTPR mode to non-transparent mode, WD19TB would report the larger number of lane(4-lane). It's over the type-c port's bandwidth. [Fix] The patch is provided by Imre(https://patchwork.freedesktop.org/series/86267/). - Calculate the PBN divider value based on the rate and lane count link parameters - that the driver uses for all other computation. + Calculate the PBN divider value based on the rate and lane count link parameters that the driver uses for all other computation. [Test Case] 1. Connected the WD19TB with the TGL platform's Type-C port and connected the external monitor on WD19TB with HDMI/Displayport. 2. Cold boot the TGL platform. 4. Check the monitor can be blinked and the video can output to the monitor. [Where problems could occur] - It's more reasonable to calculate the PBN divider based on the source's rate and lane count, - not the mst's capability. + It's more reasonable to calculate the PBN divider based on the source's rate and lane count, not the mst's capability. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1913372 Title: Fix the video can't output through WD19TB connected on TGL's Type-C port during cold-boot Status in linux package in Ubuntu: In Progress Status in linux-oem-5.10 package in Ubuntu: New Status in linux source package in Focal: New Status in linux-oem-5.10 source package in Focal: In Progress Status in linux source package in Hirsute: In Progress Status in linux-oem-5.10 source package in Hirsute: New Bug description: [Impact] WD19TB would report the number of lane(2-lane) and it works well on Type-C port of TGL platform. Change the LTTPR mode to non-transparent mode, WD19TB would report the larger number of lane(4-lane). It's over the type-c port's bandwidth. [Fix] The patch is provided by Imre(https://patchwork.freedesktop.org/series/86267/). Calculate the PBN divider value based on the rate and lane count link parameters that the driver uses for all other computation. [Test Case] 1. Connected the WD19TB with the TGL platform's Type-C port and connected the external monitor on WD19TB with HDMI/Displayport. 2. Cold boot the TGL platform. 4. Check the monitor can be blinked and the video can output to the monitor. [Where problems could occur] It's more reasonable to calculate the PBN divider based on the source's rate and lane count, not the mst's capability. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1913372/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
