Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH] net: via-rhine: fix compiler warning | Date | Wed, 30 Apr 2014 09:57:40 +0000 |
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From: Jan Moskyto Matejka > > > So why not just: > > > revision = (unsigned long)match->data; > > > and add a comment that the 0x84 is the revision - #define ?? > > > > There is no particular reason why it should be u32 now - this is a > > leftover from the previous iteration of code where revision was a > > separate property in DT (sized u32). It actually mirrors the > > respective field in struct pci_dev, which is u8 - don't see any issue > > defining it as unsigned long (and also changing the definition in > > struct rhine_private). > > > > The comment that it's the revision is right above the match table (cut > > off in the patch) :) > > > > Jan, would you prefer to adjust your patch, or shall I send another > > one to change rp->revision and friends to unsigned long? > > I prefer you to make another patch, you obviously know more about this > driver. Also thanks for suggesting (void*)->(unsigned long), I didn't > know that these two are defined to have the same size (in kernel code).
The kernel assumes that throughout - the double cast is common. The C99 type is uintptr_t - but I don't think that is defined in kernel. The only place I know where sizeof (long) != sizeof (void *) is 64bit windows. So anyone trying to compile a linux driver to run in the windows kernel might have issues (never mind the GPL ones).
David
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