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    <title>topic G2D GPU Cache Questions in i.MX Processors</title>
    <link>https://community.nxp.com/t5/i-MX-Processors/G2D-GPU-Cache-Questions/m-p/709936#M110360</link>
    <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;P&gt;We are experiencing AXI bus errors when using the G2D GPU.&amp;nbsp; This seems to be some race condition as it occurs rarely (it is only seen 1 time out 100 when running our gstreamer application).&amp;nbsp; Using uncached&amp;nbsp;memory during g2d_alloc() seems to solve the problem, but is not obviously not the best solution.&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;My best theory at the moment is that this is an allocation/deallocation issue occuring whilst the G2D GPU is running.&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;We are using&amp;nbsp;release 5.0.11.p8.6.&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;Specific Questions about g2d (imx-vpu-gpu):&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;1. The g2d_alloc(), g2d_cache_op() functions. Where is the cache? Is this just the ARM caches, or is there some 2d GPU specific cache? My assumption is that this is just managing the ARM caches.&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;2. Is the g2d_cache_op() immediate or is it queued like g2d_copy(), g2d_blit() GPU operations. i.e. do we need to run g2d_finish() to make sure the operation has completed? Obviously if this is just managing the CPU cache then I assume it is immediate.&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;This issue is being also progressed on the gstreamer-imx community -&amp;nbsp;&lt;A _jive_internal="true" href="https://community.nxp.com/external-link.jspa?url=https%3A%2F%2Fgithub.com%2FFreescale%2Fgstreamer-imx%2Fissues%2F172" rel="nofollow" target="_blank"&gt;2D GPU AXI BUS error during repeated destruction and creation of pipeline · Issue #172 · Freescale/gstreamer-imx · GitHu…&lt;/A&gt;&amp;nbsp;&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;JamesCC&lt;/P&gt;&lt;P&gt;&lt;STRONG&gt;Original Attachment has been moved to: &lt;A _jive_internal="true" href="https://community.nxp.com/docs/DOC-337116"&gt;axi_bus_error.txt.zip&lt;/A&gt;&lt;/STRONG&gt;&lt;/P&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
    <pubDate>Thu, 19 Oct 2017 08:48:59 GMT</pubDate>
    <dc:creator>jamescovey-crum</dc:creator>
    <dc:date>2017-10-19T08:48:59Z</dc:date>
    <item>
      <title>G2D GPU Cache Questions</title>
      <link>https://community.nxp.com/t5/i-MX-Processors/G2D-GPU-Cache-Questions/m-p/709936#M110360</link>
      <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;P&gt;We are experiencing AXI bus errors when using the G2D GPU.&amp;nbsp; This seems to be some race condition as it occurs rarely (it is only seen 1 time out 100 when running our gstreamer application).&amp;nbsp; Using uncached&amp;nbsp;memory during g2d_alloc() seems to solve the problem, but is not obviously not the best solution.&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;My best theory at the moment is that this is an allocation/deallocation issue occuring whilst the G2D GPU is running.&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;We are using&amp;nbsp;release 5.0.11.p8.6.&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;Specific Questions about g2d (imx-vpu-gpu):&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;1. The g2d_alloc(), g2d_cache_op() functions. Where is the cache? Is this just the ARM caches, or is there some 2d GPU specific cache? My assumption is that this is just managing the ARM caches.&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;2. Is the g2d_cache_op() immediate or is it queued like g2d_copy(), g2d_blit() GPU operations. i.e. do we need to run g2d_finish() to make sure the operation has completed? Obviously if this is just managing the CPU cache then I assume it is immediate.&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;This issue is being also progressed on the gstreamer-imx community -&amp;nbsp;&lt;A _jive_internal="true" href="https://community.nxp.com/external-link.jspa?url=https%3A%2F%2Fgithub.com%2FFreescale%2Fgstreamer-imx%2Fissues%2F172" rel="nofollow" target="_blank"&gt;2D GPU AXI BUS error during repeated destruction and creation of pipeline · Issue #172 · Freescale/gstreamer-imx · GitHu…&lt;/A&gt;&amp;nbsp;&lt;/P&gt;&lt;P style="min-height: 8pt; padding: 0px;"&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;JamesCC&lt;/P&gt;&lt;P&gt;&lt;STRONG&gt;Original Attachment has been moved to: &lt;A _jive_internal="true" href="https://community.nxp.com/docs/DOC-337116"&gt;axi_bus_error.txt.zip&lt;/A&gt;&lt;/STRONG&gt;&lt;/P&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
      <pubDate>Thu, 19 Oct 2017 08:48:59 GMT</pubDate>
      <guid>https://community.nxp.com/t5/i-MX-Processors/G2D-GPU-Cache-Questions/m-p/709936#M110360</guid>
      <dc:creator>jamescovey-crum</dc:creator>
      <dc:date>2017-10-19T08:48:59Z</dc:date>
    </item>
    <item>
      <title>Re: G2D GPU Cache Questions</title>
      <link>https://community.nxp.com/t5/i-MX-Processors/G2D-GPU-Cache-Questions/m-p/709937#M110361</link>
      <description>&lt;HTML&gt;&lt;HEAD&gt;&lt;/HEAD&gt;&lt;BODY&gt;&lt;P&gt;Hello JamesCC,&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;I see that the you closed the case and that you posted your findings there (link below)&lt;/P&gt;&lt;P&gt;&lt;A class="link-titled" href="https://github.com/Freescale/gstreamer-imx/issues/172" title="https://github.com/Freescale/gstreamer-imx/issues/172"&gt;2D GPU AXI BUS error during repeated destruction and creation of pipeline · Issue #172 · Freescale/gstreamer-imx · GitHu…&lt;/A&gt;&amp;nbsp;&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;I'm glad the problem looks solved, thank you very much! I'm mentioning this in case it can benefit other users of the Communities.&lt;/P&gt;&lt;P&gt;&lt;/P&gt;&lt;P&gt;Regards,&lt;/P&gt;&lt;/BODY&gt;&lt;/HTML&gt;</description>
      <pubDate>Tue, 24 Oct 2017 16:17:19 GMT</pubDate>
      <guid>https://community.nxp.com/t5/i-MX-Processors/G2D-GPU-Cache-Questions/m-p/709937#M110361</guid>
      <dc:creator>gusarambula</dc:creator>
      <dc:date>2017-10-24T16:17:19Z</dc:date>
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