Re: [RFC PATCH 1/4] drm/etnaviv: Prevent IRQ triggering at probe time on i.MX8MM

From: Daniel Baluta
Date: Thu Apr 30 2020 - 10:23:56 EST


On 4/30/20 3:46 PM, Schrempf Frieder wrote:
+ /*
+ * On i.MX8MM there is an interrupt getting triggered immediately
+ * after requesting the IRQ, which leads to a stall as the handler
+ * accesses the GPU registers whithout the clock being enabled.
+ * Enabling the clocks briefly seems to clear the IRQ state, so we do
+ * this here before requesting the IRQ.
+ */
+ err = etnaviv_gpu_clk_enable(gpu);
+ if (err)
+ return err;
+
+ err = etnaviv_gpu_clk_disable(gpu);
+ if (err)
+ return err;
+
+ err = devm_request_irq(&pdev->dev, gpu->irq, irq_handler, 0,
+ dev_name(gpu->dev), gpu);
+ if (err) {
+ dev_err(dev, "failed to request IRQ%u: %d\n", gpu->irq, err);
+ return err;
+ }

Shouldn't you disable the clk after devm_request_irq is called?