[PATCH v7 02/25] dmaengine: dw-edma: Release requested IRQs on failure

[Serge Semin]

>From very beginning of the DW eDMA driver live in the kernel the method
dw_edma_irq_request() hasn't been designed quite correct. In case if the
request_irq() method fails to initialize the IRQ handler at some point the
previously requested IRQs will be left initialized. It's prune to errors
up to the system crash. Let's fix that by releasing the previously
requested IRQs in the cleanup-on-error path of the dw_edma_irq_request()
function.

Fixes: e63d79d1ffcd ("dmaengine: Add Synopsys eDMA IP core driver")
Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Tested-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Acked-by: Vinod Koul <vkoul@xxxxxxxxxx>

---

Changelog v2:
- This is a new patch added in v2 iteration of the series.
---
 drivers/dma/dw-edma/dw-edma-core.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index c54b24ff5206..a8c1bd9c7ae9 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -893,10 +893,8 @@ static int dw_edma_irq_request(struct dw_edma *dw,
 						dw_edma_interrupt_read,
 					  IRQF_SHARED, dw->name,
 					  &dw->irq[i]);
-			if (err) {
-				dw->nr_irqs = i;
-				return err;
-			}
+			if (err)
+				goto err_irq_free;
 
 			if (irq_get_msi_desc(irq))
 				get_cached_msi_msg(irq, &dw->irq[i].msi);
@@ -905,6 +903,14 @@ static int dw_edma_irq_request(struct dw_edma *dw,
 		dw->nr_irqs = i;
 	}
 
+	return 0;
+
+err_irq_free:
+	for  (i--; i >= 0; i--) {
+		irq = chip->ops->irq_vector(dev, i);
+		free_irq(irq, &dw->irq[i]);
+	}
+
 	return err;
 }
 
-- 
2.38.1