On Thu, 17 May 2007 13:12:35 -0700
Andrew Morton <[EMAIL PROTECTED]> wrote:
> The patch generates warnings:
>
> drivers/ata/sata_nv.c:2118: warning: cast from pointer to integer of
> different size
> drivers/ata/sata_nv.c:2118: warning: cast to pointer from integer of
> different size
>
> due to some quite suspicious-looknig code:
>
> prd = (struct ata_prd*)((u64)pp->prd + ATA_PRD_TBL_SZ*qc->tag);
>
> we have
>
> struct ata_prd {
> u32 addr;
> u32 flags_len;
> };
>
> and the code is casting a pointer to this into a pointer to u64, then
> adding stuff to it, then casting it back to the correct type.
>
> Can't we simply do this?
>
> ---
> a/drivers/ata/sata_nv.c~drivers-ata-add-sw-ncq-support-to-sata_nv-for-mcp51-mcp55-mcp61-fix
> +++ a/drivers/ata/sata_nv.c
> @@ -2115,7 +2115,7 @@ static void nv_fill_sg(struct ata_queued
> WARN_ON(qc->__sg == NULL);
> WARN_ON(qc->n_elem == 0 && qc->pad_len == 0);
>
> - prd = (struct ata_prd*)((u64)pp->prd + ATA_PRD_TBL_SZ*qc->tag);
> + prd = pp->prd + ATA_PRD_TBL_SZ*qc->tag;
>
> idx = 0;
> ata_for_each_sg(sg, qc) {
hm, no.
ugh, I dunno what's going on here and I think I'd prefer not to. Can't
we come up with some typesafe way of doing this without casting?
Meanwhile, I'll switch the cast from u64 to long.
-
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