<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=utf-8"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:Wingdings;
panose-1:5 0 0 0 0 0 0 0 0 0;}
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:DengXian;
panose-1:2 1 6 0 3 1 1 1 1 1;}
@font-face
{font-family:DengXian;
panose-1:2 1 6 0 3 1 1 1 1 1;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
text-align:justify;
text-justify:inter-ideograph;
font-size:10.5pt;
font-family:DengXian;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
margin:0cm;
margin-bottom:.0001pt;
text-align:justify;
text-justify:inter-ideograph;
text-indent:21.0pt;
font-size:10.5pt;
font-family:DengXian;}
span.DefaultFontHxMailStyle
{mso-style-name:"Default Font HxMail Style";
font-family:DengXian;
color:windowtext;
font-weight:normal;
font-style:normal;
text-decoration:none none;}
.MsoChpDefault
{mso-style-type:export-only;}
/* Page Definitions */
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 90.0pt 72.0pt 90.0pt;}
div.WordSection1
{page:WordSection1;}
/* List Definitions */
@list l0
{mso-list-id:1496729359;
mso-list-type:hybrid;
mso-list-template-ids:-1873276564 -1 67698691 67698693 67698689 67698691 67698693 67698689 67698691 67698693;}
@list l0:level1
{mso-level-start-at:0;
mso-level-number-format:bullet;
mso-level-text:\F0D8;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:18.0pt;
text-indent:-18.0pt;
font-family:Wingdings;
mso-fareast-font-family:DengXian;
mso-bidi-font-family:"Times New Roman";}
@list l0:level2
{mso-level-number-format:bullet;
mso-level-text:\F06E;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:42.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
@list l0:level3
{mso-level-number-format:bullet;
mso-level-text:\F075;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:63.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
@list l0:level4
{mso-level-number-format:bullet;
mso-level-text:\F06C;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:84.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
@list l0:level5
{mso-level-number-format:bullet;
mso-level-text:\F06E;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:105.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
@list l0:level6
{mso-level-number-format:bullet;
mso-level-text:\F075;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:126.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
@list l0:level7
{mso-level-number-format:bullet;
mso-level-text:\F06C;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:147.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
@list l0:level8
{mso-level-number-format:bullet;
mso-level-text:\F06E;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:168.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
@list l0:level9
{mso-level-number-format:bullet;
mso-level-text:\F075;
mso-level-tab-stop:none;
mso-level-number-position:left;
margin-left:189.0pt;
text-indent:-21.0pt;
font-family:Wingdings;}
ol
{margin-bottom:0cm;}
ul
{margin-bottom:0cm;}
--></style></head><body lang=ZH-CN link=blue vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span lang=EN-US>Hi,</span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>On Mon, 9 Sep 2019 from Gerd Hoffmann <kraxel@redhat.com><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>> Hmm, I think the patch is wrong. As far I know it is the qxl drivers's</span></p><p class=MsoNormal><span lang=EN-US>> job to call ttm_eu_backoff_reservation(). Doing that automatically in</span></p><p class=MsoNormal><span lang=EN-US>> ttm will most likely break other ttm users.</span></p><p class=MsoNormal><span lang=EN-US>><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Perhaps.</span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>>So I guess the call is missing in the qxl driver somewhere, most likely</span></p><p class=MsoNormal><span lang=EN-US>>in some error handling code path given that this bug is a relatively</span></p><p class=MsoNormal><span lang=EN-US>>rare event.</span></p><p class=MsoNormal><span lang=EN-US>><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>>There is only a single ttm_eu_reserve_buffers() call in qxl.</span></p><p class=MsoNormal><span lang=EN-US>>So how about this?</span></p><p class=MsoNormal><span lang=EN-US>><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>No preference in either way if it is a right cure.</span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>BTW a quick peep at the mainline tree shows not every</span></p><p class=MsoNormal><span lang=EN-US>ttm_eu_reserve_buffers() pairs with ttm_eu_backoff_reservation()</span></p><p class=MsoNormal><span lang=EN-US>without qxl being taken in account.</span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span lang=EN-US><o:p> </o:p></span></span></p><p class=MsoNormal><span class=DefaultFontHxMailStyle><span lang=EN-US>Hillf<o:p></o:p></span></span></p></div></body></html>