RE: [PATCH cciss: fix printk format warning

["Miller, Mike (OS Dev)" <Mike.Miller@hp.com>]

> -----Original Message-----
> From: Cameron, Steve 
> Sent: Friday, October 27, 2006 8:12 AM
> To: Randy Dunlap; Roland Dreier
> Cc: Andrew Morton; ISS StorageDev; lkml
> Subject: RE: [PATCH cciss: fix printk format warning
> 
> > Roland Dreier wrote:
> > >  > >  	if (*total_size != (__u32) 0)
> > >  >
> > >  > Why is cciss_read_capacity casting *total_size to u32?
> > > 
> > > It's not -- it's actually casting 0 to __32 -- there's no cast on 
> > > the *total_size side of the comparison.  However that 
> just makes the 
> > > cast look even fishier.

If the volume is >2TB read_capacity will return 8 F's. We've already
added 1 to total_size which equals 0. I only care if the lower 32 bits
are zero so that's the reason for the cast.
Does that make sense or am I out in the weeds?

mikem

> > > 
> > >  - R.
> > 
> > OK, how about this one then?
> > 
> > 
> > 	c->busaddr = (__u32) cmd_dma_handle;
> > 
> > where cmd_dma_handle is a dma_addr_t (u32 or u64)
> 
> The command register to which that value is written is a 32 
> bit register.  Cast it or not, only 32 bits will be used.  
> The DMA mask used to get that memory should ensure it's 32 
> bit addressable.
> 
> > and then later:
> >
> >		pci_free_consistent(h->pdev, sizeof(CommandList_struct),
> >				    c, (dma_addr_t) c->busaddr);
> 
> 
> 
> 
> 
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/