On 29/10/2019 14:32, Andrew Lunn wrote:
+static int cpsw_probe(struct platform_device *pdev)
+{
+ const struct soc_device_attribute *soc;
+ struct device *dev = &pdev->dev;
+ struct resource *ss_res;
+ struct cpsw_common *cpsw;
+ struct gpio_descs *mode;
+ void __iomem *ss_regs;
+ int ret = 0, ch;
+ struct clk *clk;
+ int irq;
+
...
+
+ /* setup netdevs */
+ ret = cpsw_create_ports(cpsw);
+ if (ret)
+ goto clean_unregister_netdev;
At this point, the slave ports go live. If the kernel is configured
with NFS root etc, it will start using the interfaces.
+
+ /* Grab RX and TX IRQs. Note that we also have RX_THRESHOLD and
+ * MISC IRQs which are always kept disabled with this driver so
+ * we will not request them.
+ *
+ * If anyone wants to implement support for those, make sure to
+ * first request and append them to irqs_table array.
+ */
+
+ ret = devm_request_irq(dev, cpsw->irqs_table[0], cpsw_rx_interrupt,
+ 0, dev_name(dev), cpsw);
+ if (ret < 0) {
+ dev_err(dev, "error attaching irq (%d)\n", ret);
+ goto clean_unregister_netdev;
+ }
+
+ ret = devm_request_irq(dev, cpsw->irqs_table[1], cpsw_tx_interrupt,
+ 0, dev_name(dev), cpsw);
+ if (ret < 0) {
+ dev_err(dev, "error attaching irq (%d)\n", ret);
+ goto clean_unregister_netdev;
+ }
Are there any race conditions if the network starts using the devices
before interrupts are requested? To be safe, maybe this should be done
before the slaves are created?
Usually during boot - there is no parallel probing (as opposite to modules loading by
udev, for example). Also, there is barrier init call deferred_probe_initcall() to ensure all
drivers probed before going to mount rootfs.
So, i do not think this could cause any issue - max few packets will be delayed
until kernel will switch back here, but the chances that ndo_open will be finished before probe ->0.
--
Best regards,
grygorii
