[POWERPC] Simplify rtas_change_msi() error semantics
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 <michael@ellerman.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
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 @@
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 @@
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 @@
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;
}