Nikolaus Meine <meine <at> tnt.uni-hannover.de> writes:
>
> After upgrading from kernel 3.11 to 3.12 my USB 3.0 card reader
> (Transcend RDF8) stopped working with the same error.
>
> I managed to find the code line which triggered the erroneous behaviour:
>
> It's the definition of the macro xhci_dbg(...) in xhci.h line 1590/1591.
>
> In 3.11 it is
> do { if (XHCI_DEBUG) dev_dbg(...); } while (0)
>
> XHCI_DEBUG is defined as 0 because XHCI_HCD_DEBUGGING is not defined
> so this macro collapses to nothing.
>
> In 3.12 xhci_dbg(...) is defined as
> dev_dbg(...)
> which actually calls dev_printk(...) because DEBUG is defined.
>
> If I define xhci_dbg() in 3.12 as
> do { } while (0)
> my card reader starts working again.
>
> That was the good news.
> The bad news is that I have no idea why calling dev_printk(...)
> does any harm here. Maybe it's a timing problem.
>
> Best Regards
> Nikolaus Meine
>
Hello once again!
I have to correct me previous post:
The card reader does actually work with 3.12 so it's just
the dumping of debug messages which was enabled in 3.12,
no timing problem.
Best Regards
Nikolaus Meine
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
