Messages in this thread | | | Subject | Re: Si3112 S-ATA bug preventing use of udma5. | From | Roland Dreier <> | Date | 23 Apr 2004 19:30:41 -0700 |
| |
Brenden> Incase the link is down/broken, to fix the bug change line 269 Brenden> of drivers/ide/pci/siimage.c from:
Brenden> u32 speedt = 0;
Brenden> to: u16 speedt = 0;
Brenden> The crux of the problem is that the first arguent to OUTW Brenden> (out WORD) was a doubleword. The arguments were getting Brenden> all screwed up on the stack. The lower order 16-bit were Brenden> being used in the second argument of OUTW, and the upper Brenden> order word was being used as the whole first argument, Brenden> which was always 0000.
Ben> Hrm... that's strange. I'd tend to think it's a bogus Ben> definition of outw on this architecture (x86 ?) instead. an Ben> u32 should be casted down to u16 without problem.
Assuming I'm reading the siimage.c code correctly, it's calling default_hwif_mmiops() to set up its OUTW pointer, which sets the function pointer to call
static void ide_mm_outw (u16 value, unsigned long port) { writew(value, port); }
In asm-i386/io.h, we have
#define writew(b,addr) (*(volatile unsigned short *) __io_virt(addr) = (b))
Finally, siimage.c does
hwif->OUTW(speedt, addr);
and speedt is a u32 -- however, as you say, the compiler should just cast speedt down to a u16. What am I missing?
- R. - 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/
| |