Hi!<div><br></div><div>I&#39;ve made a bit of progress and now the MUSB client driver is kinda working, but</div><div>in a very hackish way.</div><div><br></div><div>The first thing I did was to disable caching and buffering in L4.. And it was a fiasco.</div>
<div>The good news is that reading IO memory via the DS attached pointer</div><div>and via the mmio Register class seems to bring identical results.</div><div><br></div><div>Turned out, the wrong data came from musb_read_fifo function.</div>
<div>This function calls __raw_readl, __raw_readb, __raw_readw functions. I think I have implemented</div><div>them correctly given that unaligned access works fine in genode. I would appreciate if someone</div><div>takes a look at them.</div>
<div><br></div><div><a href="https://github.com/astarasikov/genode/blob/omap4-otg-dirty/dde_linux/src/drivers/usb/arm/platform/lx_emul.h">https://github.com/astarasikov/genode/blob/omap4-otg-dirty/dde_linux/src/drivers/usb/arm/platform/lx_emul.h</a></div>
<div><br></div><div>Turns out, there&#39;s a single FIFO register and when you read from it or write to it, the controller immediately</div><div>feeds it with the new data. So, maybe multiple unaligned access caused it to fail.</div>
<div><br></div><div>What I did was to comment out musb_{write,read}_fifo code and manually read the data. First I decided</div><div>to read by 4-byte words, but that failed. To my surprise, reading by single bytes did the trick and the driver</div>
<div>is now receiving the correct data and the host recognizes the device, albeit at the third attempt.</div><div><br></div><div>I&#39;m attaching the dmesg from my destkop to see how the device behaves from the point I reboot</div>
<div>the pandaboard to the point the musb client driver is recognized.</div><div><br></div><div><a href="http://pastebin.com/XE7wkm26">http://pastebin.com/XE7wkm26</a></div><div><br></div><div>I&#39;m out of the ideas as to what&#39;s going on here. Does anyone have any suggestions?</div>
<div><br></div><div>And, btw, I&#39;ve found a small bug in dde_linux. In the file</div><div>dde_linux/src/drivers/usb/arm/platform/lx_emul.h</div><div>the definition SZ_4K = 0x00001000a, seems clearly wrong to me. That &#39;a&#39; at the end is probably</div>
<div>a bad typo. When I figure out the musb issues, I&#39;ll submit a pull request for this if no one else does that before.<br><br>-- <br>Regards, Alexander<br><br>
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