[PATCH 16/18] bus: mhi: core: Allow shared IRQ for event rings

[Manivannan Sadhasivam]

From: Loic Poulain <loic.poulain@xxxxxxxxxx>

There is no requirement for using a dedicated IRQ per event ring.
Some systems does not support multiple MSI vectors (e.g. intel
without CONFIG_IRQ_REMAP), In that case the MHI controller can
configure all the event rings to use the same interrupt (as fallback).

Allow this by removing the nr_irqs = ev_ring test and add extra check
in the irq_setup function.

Signed-off-by: Loic Poulain <loic.poulain@xxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
---
 drivers/bus/mhi/core/init.c | 7 +++++++
 drivers/bus/mhi/core/pm.c   | 2 +-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index 1b4161eaf0d8..049a10fa42d7 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -176,6 +176,13 @@ int mhi_init_irq_setup(struct mhi_controller *mhi_cntrl)
 		if (mhi_event->offload_ev)
 			continue;
 
+		if (mhi_event->irq >= mhi_cntrl->nr_irqs) {
+			dev_err(dev, "irq %d not available for event ring\n",
+				mhi_event->irq);
+			ret = -EINVAL;
+			goto error_request;
+		}
+
 		ret = request_irq(mhi_cntrl->irq[mhi_event->irq],
 				  mhi_irq_handler,
 				  IRQF_SHARED | IRQF_NO_SUSPEND,
diff --git a/drivers/bus/mhi/core/pm.c b/drivers/bus/mhi/core/pm.c
index ce4d969818b4..3de7b1639ec6 100644
--- a/drivers/bus/mhi/core/pm.c
+++ b/drivers/bus/mhi/core/pm.c
@@ -918,7 +918,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
 
 	dev_info(dev, "Requested to power ON\n");
 
-	if (mhi_cntrl->nr_irqs < mhi_cntrl->total_ev_rings)
+	if (mhi_cntrl->nr_irqs < 1)
 		return -EINVAL;
 
 	/* Supply default wake routines if not provided by controller driver */
-- 
2.17.1