On Sun, 2015-10-11 at 21:18 +0200, Thomas Gleixner wrote:
> Andy,
>
> On Fri, 9 Oct 2015, Andy Shevchenko wrote:
> > #ifdef CONFIG_PCI
> > static void mem32_serial_out(unsigned long addr, int offset, int
> value)
> > {
> > - u32 *vaddr = (u32 *)addr;
> > + void __iomem *vaddr = (void __iomem *)addr;
> > /* shift implied by pointer type */
> > writel(value, vaddr + offset);
>
> This is broken. Assume vaddr = 0x1000 and offset = 1
Yes, I noticed in reply to myself
http://www.spinics.net/lists/kernel/msg2094143.html
Tests were okay because platform I have is using 8-bit I/O.
Does it make sense to use the following approach?
void __iomem *vaddr = (void __iomem *)addr;
writel(value, vaddr + offset << 2);
>
> ==> u32 *vaddr = 0x1000;
> ==> vaddr + offset = 0x1004
>
> with your change
>
> ==> void __iomem *vaddr = 0x1000;
>
> ==> vaddr + offset = 0x1001
>
> This comment is there for a reason:
> > /* shift implied by pointer type */
>
> Thanks,
>
> tglx
--
Andy Shevchenko <[email protected]>
Intel Finland Oy
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