Re: usb: descriptor structures have to be packed
"Phil Endecott" <[email protected]>
| Newsgroups | gmane.linux.usb.devel |
|---|---|
| Message-ID | <[email protected]> |
Oleg Verych wrote: >> From: "Phil Endecott" <[email protected]> > Just question. > >> void inc(int __attribute__((aligned(1))) * i) >> void inc(int * __attribute__((aligned(1))) i) >> void inc(int * i __attribute__((aligned(1)))) > > Why 1, and not 2? 1 is the "worst" unalignment. If I specify 2 I get the same errors/issues (as expected). What difference do you expect to see? > While i didn't read (so far your links), and i wasn't in such > situation, may i redirect you to this patch: > > http://marc.theaimsgroup.com/?l=linux-mm-commits&m=117087868602789&w=2 This patch is: "Prevent an unaligned exception to occur. (GCC 4.1) tmp is defined as char pointer while it is later accessed as short." This is, in a sense, the opposite of what we're looking at. There they have added aligned(2) to a char; that makes it more aligned so it's safe. Adding packed attributes reduces the alignment, which is not always safe. Phil. ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier. Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel