Any News on cut-and-paste bug?
John G. Heim
jheim at math.wisc.edu
Wed May 1 12:23:54 EDT 2013
On 05/01/13 10:45, Samuel Thibault wrote:
> John G. Heim, le Wed 01 May 2013 10:42:39 -0500, a écrit :
>> All I wanted to do was get rid of what I suspected was a call to a function
>> that apparently did nothing and the subsequent erroring out. But nobody
>> seemed to know what the function did or if they did, they weren't sharing.
>> They did, however, take the time to criticize the speakup code itself.
>
> Do you have a reference of the thread? (like the precise date when it
> happened, or the subject, etc.)
Here are 2 of the messages I posted. I haven't found an archive of the
linux-kernel list. But I haven't looked too hard. But these messages
show the exact date and subject line of the 2 threads on the list.
On 03/03/12 11:18, John G. Heim wrote:
>Subject: speakup bug
> I need help fixing a bug in the driver for serial hardware speech
> synths in the speakup screen reader. According to the comments in the
> code, it is in a part of the code that is trying to "steal" the serial
> port.
>
> First it calls request_region and when that fails (it always fails), it
> calls __release_region(&then it calls release_region again to
> see if __release_region worked. But it never works because the region
> being requested is already taken.
>
> The code in question is in 2 source code files in
> drivers/staging/speakup. It starts in serialio.c on line 38. Here it
> calls a function named synth_request_region which in turn, calls
> request_region. On line 41 it calls __release_region, and on line 42 it
> calls synth_request_region again. The function synth_request_region
> (which calls request_region) is in a file named synth.c. But this code
> always fails. Here is a kind of simplified version of it...
>
> int error;
> struct resource tmp;
> tmp .name = "ltlk";
> tmps.start = 0x3F8;
> tmp.end = 0x3FF;
> tmp.flags = IORESOURCE_BUSY;
> error = request_resource (&ioport_resource, &tmp);
>
> The error returned is always -16. I looked at the code in
> kernel/resource.c where the request_region function is defined. It
> builds a linked list of resources with start & end addresses. If you
> request a region that is already within the start-end range of a
> resource already in the list, it returns an error code. But it looks as
> if the region for a serial port, 0x3f8 - 0x3ff, in ioport_resource
> cannot be reserved because the entire range from 0x000 through 0xcf7 is
> already taken by something named "PCI Bus 0000:00". Therefore calling
> request_resource always fails and the driver for the speech synth errors
> out.
>
> And therefore I can't use my hardware speech synth without modifying the
> kernel code. If you comment out the line that checks the return code
> from request_region, it works. So you have to modify the kernel code
> and compile a custom kernel to use a hardware speech synth. That's not
> such a problem for me but it is for a lot of people. Plus, the grml live
> CD doesn't work with hardware speech. That is a problem for me.
>
> Can anyone tell me how to fix this so it can be patched in the official
> kernel code?
>
On 05/11/12 10:36, John Heim wrote:
>Subject: patch for speakup serial hardware synths
> A few weeks ago I asked about a problem with the speakup screen reader
> code. It does not work with serial hardware speech synthesizers. But I
> managed to get it working. How can I submit my fix for integration into
> the kernel code. The patch file can be downloaded here:
> http://www.math.wisc.edu/~jheim/downloads/patch-2012-03-06.patch
>
> To install it you cd to the linux source directory and do this:
> patch -i patch-2012-03-06.patch drivers/staging/speakup/serialio.c"
>
More information about the Speakup
mailing list