lkml.org 
[lkml]   [2006]   [Oct]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRE: [PATCH cciss: fix printk format warning
Date
From


> -----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/

\
 
 \ /
  Last update: 2006-10-27 17:19    [W:0.047 / U:1.444 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site