Re: [PATCH V4 4/6] slim: qcom: Add Qualcomm Slimbus controller driver

On Sat, Feb 06, 2016 at 11:44:23AM -0700, Sagar Dharia wrote:

 
+if SLIMBUS
+config SLIM_QCOM_CTRL
+	tristate "Qualcomm Slimbus Manager Component"
+	depends on SLIMBUS
+	default n
+	help

n is the default.

+static irqreturn_t msm_slim_interrupt(int irq, void *d)
+{
+	struct msm_slim_ctrl *dev = d;
+	u32 stat = readl_relaxed(dev->base + MGR_INT_STAT);
+	int err = 0;

+	if (stat & MGR_INT_TX_MSG_SENT || stat & MGR_INT_TX_NACKED_2) {

+	if (stat & MGR_INT_RX_MSG_RCVD) {

+	}

+	/**
+	 * All interrupts are handled: complex RX messages requiring more work
+	 * are queued to work-queue, others are handled above
+	 */
+	return IRQ_HANDLED;

This unconditionally returns IRQ_HANDLED even if no interrupts were
flagged.  This will break if the interrupt gets shared in some hardware
design or if something goes wrong with the hardware.

+	ret = devm_request_irq(&pdev->dev, dev->irq, msm_slim_interrupt,
+				IRQF_TRIGGER_HIGH, "msm_slim_irq", dev);
+	if (ret) {
+		dev_err(&pdev->dev, "request IRQ failed\n");
+		goto err_request_irq_failed;
+	}

Are you sure this is safe and we don't deallocate things the interrupt
handler uses before we disable the interrupt?

+	ret = clk_prepare_enable(hclk);
+	if (ret)
+		goto err_hclk_enable_failed;
+
+	ret = clk_prepare_enable(rclk);
+	if (ret)
+		goto err_rclk_enable_failed;

The remove path doesn't disable these.

+	/* Register with framework before enabling frame, clock */
+	ret = slim_register_controller(&dev->ctrl);
+	if (ret) {
+		dev_err(dev->dev, "error adding controller\n");
+		goto err_ctrl_failed;
+	}

Should we have a devm_ version of slim_register_controller()?  I'd also
expect this to be the last thing we do in probe, things may start using
the device before we've finished initializing it.