tg3: Fix single-vector MSI-X code
Kdump kernels leave MSI-X interrupts (as setup by the crashed kernel)
enabled. However, kdump only enables one CPU in the new environment,
thus causing tg3 to abort MSI-X setup. When the driver attempts to
enable INTA or MSI interrupt modes on a kdump kernel, interrupt
delivery fails.
This patch attempts to workaround the problem by forcing the driver
to enable a single MSI-X interrupt. In such a configuration, the
device's multivector interrupt mode must be disabled.
Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 076e02a..d529af9 100644
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -8846,9 +8846,11 @@
tw32_f(GRC_LOCAL_CTRL, tp->grc_local_ctrl);
udelay(100);
- if (tg3_flag(tp, USING_MSIX) && tp->irq_cnt > 1) {
+ if (tg3_flag(tp, USING_MSIX)) {
val = tr32(MSGINT_MODE);
- val |= MSGINT_MODE_MULTIVEC_EN | MSGINT_MODE_ENABLE;
+ val |= MSGINT_MODE_ENABLE;
+ if (tp->irq_cnt > 1)
+ val |= MSGINT_MODE_MULTIVEC_EN;
if (!tg3_flag(tp, 1SHOT_MSI))
val |= MSGINT_MODE_ONE_SHOT_DISABLE;
tw32(MSGINT_MODE, val);
@@ -9548,19 +9550,18 @@
static bool tg3_enable_msix(struct tg3 *tp)
{
- int i, rc, cpus = num_online_cpus();
+ int i, rc;
struct msix_entry msix_ent[tp->irq_max];
- if (cpus == 1)
- /* Just fallback to the simpler MSI mode. */
- return false;
-
- /*
- * We want as many rx rings enabled as there are cpus.
- * The first MSIX vector only deals with link interrupts, etc,
- * so we add one to the number of vectors we are requesting.
- */
- tp->irq_cnt = min_t(unsigned, cpus + 1, tp->irq_max);
+ tp->irq_cnt = num_online_cpus();
+ if (tp->irq_cnt > 1) {
+ /* We want as many rx rings enabled as there are cpus.
+ * In multiqueue MSI-X mode, the first MSI-X vector
+ * only deals with link interrupts, etc, so we add
+ * one to the number of vectors we are requesting.
+ */
+ tp->irq_cnt = min_t(unsigned, tp->irq_cnt + 1, tp->irq_max);
+ }
for (i = 0; i < tp->irq_max; i++) {
msix_ent[i].entry = i;
