On Jan 25, 2008 8:43 AM, Ke Wei <kewei.mv@xxxxxxxxx> wrote:
> The attached is Marvell 6440 SAS/SATA driver. I will try to send email
> by git-send-email.
>
Sorry, just saw some more issues in
+static void mvs_hba_interrupt_enable(struct mvs_info *mvi, int enable)
Three comments here:
1) This routine is slightly misnamed since it can both enable and disable
the interrupt. I _suggest_ to not pass in "enable" parameter and add a
mvs_hba_interrupt_disable() to deal with (2) and (3) below.
2) On interrupt disable, MMIO write posting _could_ be a problem here.
ie interrupts could be generated after calling this routine since it doesn't
force the MMIO write to the PCI device with an MMIO read.
(For more info on this see chapter 4 of
http://iou.parisc-linux.org/ols_2002/ )
3) Even after fixing (2), interrupts can already be in-flight and not
yet delivered.
Higher level code needs to make sure it can tolerate a "late arriving" IRQ.
One MMIO read should mostly solve this for MSI but not for Line-based IRQ.
(MMIO Read-return will flush inflight MSI).
hth,
grant
-
To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
