Re: [PATCH 1/4] scsi: megaraid_sas - Add the dumy readl to force PCI flush

[Andrew Morton <akpm@linux-foundation.org>]

On Fri, 1 Aug 2008 10:19:07 -0600 "Yang, Bo" <Bo.Yang@lsi.com> wrote:

> MegaRAID SAS Driver get unexpected Interrupt.  Add the dumy readl to force PCI flush will fix this issue.
> 
> Signed-off-by Bo Yang<bo.yang@lsi.com>
> 
> ---
> drivers/scsi/megaraid/megaraid_sas.c |    6 ++++++
> 1 files changed, 6 insertions(+)
> 
> diff -rupN linux-2.6.28_orig/drivers/scsi/megaraid/megaraid_sas.c linux-2.6.28_new/drivers/scsi/megaraid/megaraid_sas.c
> --- linux-2.6.28_orig/drivers/scsi/megaraid/megaraid_sas.c      2008-07-31 12:00:58.000000000 -0400
> +++ linux-2.6.28_new/drivers/scsi/megaraid/megaraid_sas.c       2008-07-31 12:30:35.000000000 -0400
> @@ -198,6 +198,9 @@ megasas_clear_intr_xscale(struct megasas
>          */
>         writel(status, &regs->outbound_intr_status);
> 
> +       /* Dummy readl to force pci flush */
> +       readl(&regs->outbound_intr_status);
> +
>         return 0;
>  }
> 
> @@ -293,6 +296,9 @@ megasas_clear_intr_ppc(struct megasas_re
>          */
>         writel(status, &regs->outbound_doorbell_clear);
> 
> +       /* Dummy readl to force pci flush */
> +       readl(&regs->outbound_doorbell_clear);
> +
>         return 0;
>  }
>  /**

These patches all had their tabs replaced with spaces.  I fixed them up.

Please always run checkpatch on all patches.  checkpatch found this:

ERROR: Macros with complex values should be enclosed in parenthesis
#182: FILE: drivers/scsi/megaraid/megaraid_sas.h:586:
+#define MFI_GEN2_ENABLE_INTERRUPT_MASK		0x00000001 | 0x00000004

which is a potential source of bugs.  I queued a patch to fix that also.