On Thu, 2007-09-20 at 16:36 +1000, Michael Ellerman wrote:
> Currently rtas_change_msi() returns either the error code from RTAS, or if
> the RTAS call succeeded the number of irqs that were configured by RTAS.
> This makes checking the return value more complicated than it needs to be.
>
> Instead, have rtas_change_msi() check that the number of irqs configured by
> RTAS is equal to what we requested - and return an error otherwise. This makes
> the return semantics match the usual 0 for success, something else for error.
>
> Signed-off-by: Michael Ellerman <[EMAIL PROTECTED]>
Looks allright, just a question tho... what do we do if it fails ? Do we
try to fallback to a lower number of MSIs ? Or what ? Dead device ?
Ben.
> ---
> arch/powerpc/platforms/pseries/msi.c | 18 +++++++++++-------
> 1 files changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/arch/powerpc/platforms/pseries/msi.c
> b/arch/powerpc/platforms/pseries/msi.c
> index 9c3bcfe..2793a1b 100644
> --- a/arch/powerpc/platforms/pseries/msi.c
> +++ b/arch/powerpc/platforms/pseries/msi.c
> @@ -70,11 +70,15 @@ static int rtas_change_msi(struct pci_dn *pdn, u32 func,
> u32 num_irqs)
> seq_num = rtas_ret[1];
> } while (rtas_busy_delay(rc));
>
> - if (rc == 0) /* Success */
> - rc = rtas_ret[0];
> + /*
> + * If the RTAS call succeeded, check the number of irqs is actually
> + * what we asked for. If not, return an error.
> + */
> + if (rc == 0 && rtas_ret[0] != num_irqs)
> + rc = -ENOSPC;
>
> - pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d) = (%d)\n",
> - func, num_irqs, rc);
> + pr_debug("rtas_msi: ibm,change_msi(func=%d,num=%d), got %d rc = %d\n",
> + func, num_irqs, rtas_ret[0], rc);
>
> return rc;
> }
> @@ -87,7 +91,7 @@ static void rtas_disable_msi(struct pci_dev *pdev)
> if (!pdn)
> return;
>
> - if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0) != 0)
> + if (rtas_change_msi(pdn, RTAS_CHANGE_FN, 0))
> pr_debug("rtas_msi: Setting MSIs to 0 failed!\n");
> }
>
> @@ -180,14 +184,14 @@ static int rtas_setup_msi_irqs(struct pci_dev *pdev,
> int nvec, int type)
> if (type == PCI_CAP_ID_MSI) {
> rc = rtas_change_msi(pdn, RTAS_CHANGE_MSI_FN, nvec);
>
> - if (rc != nvec) {
> + if (rc) {
> pr_debug("rtas_msi: trying the old firmware call.\n");
> rc = rtas_change_msi(pdn, RTAS_CHANGE_FN, nvec);
> }
> } else
> rc = rtas_change_msi(pdn, RTAS_CHANGE_MSIX_FN, nvec);
>
> - if (rc != nvec) {
> + if (rc) {
> pr_debug("rtas_msi: rtas_change_msi() failed\n");
> return rc;
> }
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