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      <base href="https://bugs.freedesktop.org/">
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW - No Screen Updates on fbcon with PSR enabled on Thinkpad T450s (Broadwell), Linux 5.1.5"
   href="https://bugs.freedesktop.org/show_bug.cgi?id=110799">110799</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>No Screen Updates on fbcon with PSR enabled on Thinkpad T450s (Broadwell), Linux 5.1.5
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>DRI
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>unspecified
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>x86-64 (AMD64)
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Linux (All)
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>medium
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>DRM/Intel
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>intel-gfx-bugs@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>trohwer85@gmail.com
          </td>
        </tr>

        <tr>
          <th>QA Contact</th>
          <td>intel-gfx-bugs@lists.freedesktop.org
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>intel-gfx-bugs@lists.freedesktop.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>I enabled PSR on my Thinkpad T450s (Broadwell) with Linux 5.1.5. This works
fine under X, but I get no screen updates on the fbcon (typing etc. does show
no change on screen, only switching to/back X makes the stuff visible).
Without PSR, the fbcon works fine.

I investigated a bit and identified this code in drm/i915/intel_psr.c
(printk added by me) to exit PSR on fbcon dirty calls:

  /* By definition flush = invalidate + flush */
  if (frontbuffer_bits) {
    /*
     * Display WA #0884: all
     * This documented WA for bxt can be safely applied
     * broadly so we can force HW tracking to exit PSR
     * instead of disabling and re-enabling.
     * Workaround tells us to write 0 to CUR_SURFLIVE_A,
     * but it makes more sense write to the current active
     * pipe.
     */
    printk(KERN_DEBUG "WA\n");
    I915_WRITE(CURSURFLIVE(dev_priv->psr.pipe), 0);
  }

The code is called for fbcon changes, but as stated, it does not seem to have
the effect of exiting PSR on my hardware.</pre>
        </div>
      </p>


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