<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Hi -<div class=""><br class=""></div><div class="">Note - I know that this is not a Xenomai mailing list - however I have already posted there and it appears that the problems I am seeing are not from Xenomai, but rather from the use of the radeon driver.</div><div class=""><br class=""></div><div class=""><div class="">Setup - I am using a custom-compiled Linux kernel 3.14.17 on Ubuntu 14.04. The kernel is patched with Xenomai using Ipipe 3.14.17-x84-4.patch. I have a Radeon HD 8570HD R7 240 graphics card in this system.</div></div><div class=""><br class=""></div><div class="">I can confirm that the radeon driver is compiled and loaded, and by running “sudo lshw -C Display”, I can verify that my graphics card is using the Radeon driver.</div><div class=""><br class=""></div><div class="">Problem - Now, when I run the latency test in Xenomai, I obtain large latencies - up to 40us. If I blacklist the radeon, drm, drm_kms_help, ttm, i2c_algo_bit kernel modules, and run the latency test with gdm not running, the latencies are under 10us.</div><div class=""><br class=""></div><div class="">In previous kernel versions, such as 3.8.13, I have never seen such big differences in latency results between gdm running/not running.</div><div class=""><br class=""></div><div class="">I originally thought that the radeon driver in the 3.14.17 kernel may not be the latest because the date on the radeon source in the kernel is 20080523 - but it seems like that date was just never updated (according to the answer to my previous question <a href="https://www.mail-archive.com/xorg-driver-ati@lists.x.org/msg26099.html" class="">here</a>). So I assume the radeon source in the kernel is up-to-date (especially since it shows the driver supporting my graphics card).</div><div class=""><br class=""></div><div class="">The only odd things I see in dmesg is it says “drm taints the kernel; not creating trace events” The same message is present in dmesg for radeon.</div><div class=""><br class=""></div><div class="">Does anyone have any thoughts on what might be causing this or how to best debug it? I am quite lost since I don’t seem to see anything that sticks out.</div><div class=""><br class=""></div><div class=""><div apple-content-edited="true" class="">
<div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="color: rgb(0, 0, 0); letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">Yogi</div></div></div></div></div></div></div></body></html>