Hi,

Thanks for the review.
Comments inline.

On 09/01/2016 06:15 PM, Marc Zyngier wrote:
On 01/09/16 17:50, Zubair Lutfullah Kakakhel wrote:
The drivers read/write function handling is a bit quirky.
And the irqmask is passed directly to the handler.

Add a new irqchip struct to pass to the handler and
cleanup read/write handling.

Signed-off-by: Zubair Lutfullah Kakakhel <zubair.kakak...@imgtec.com>

---
V3 -> V4
Better error handling for kzalloc
Erroring out if the axi intc is probed twice as that isn't
supported


...

 static int __init xilinx_intc_of_init(struct device_node *intc,
                                             struct device_node *parent)
 {
-       u32 nr_irq, intr_mask;
+       u32 nr_irq;
        int ret;
+       struct xintc_irq_chip *irqc;
+
+       irqc = kzalloc(sizeof(*irqc), GFP_KERNEL);
+       if (!irqc)
+               return -ENOMEM;

-       intc_baseaddr = of_iomap(intc, 0);
-       BUG_ON(!intc_baseaddr);
+       if (xintc_irqc) {
+               pr_err("%s: Multiple instances of axi_intc aren't supported\n");
+               ret = -EINVAL;
+               goto err_alloc;

How about testing the variable first and error-ing early, rather than
performing the allocation and undoing it later?


Sure. Thanks

+       } else {
+               xintc_irqc = irqc;
+       }
+
+       irqc->base = of_iomap(intc, 0);
+       BUG_ON(!irqc->base);

        ret = of_property_read_u32(intc, "xlnx,num-intr-inputs", &nr_irq);
        if (ret < 0) {
                pr_err("%s: unable to read xlnx,num-intr-inputs\n", __func__);
-               return ret;
+               goto err_alloc;
        }

-       ret = of_property_read_u32(intc, "xlnx,kind-of-intr", &intr_mask);
+       ret = of_property_read_u32(intc, "xlnx,kind-of-intr", &irqc->intr_mask);
        if (ret < 0) {
                pr_err("%s: unable to read xlnx,kind-of-intr\n", __func__);
-               return ret;
+               goto err_alloc;
        }

-       if (intr_mask >> nr_irq)
+       if (irqc->intr_mask >> nr_irq)
                pr_warn("%s: mismatch in kind-of-intr param\n", __func__);

        pr_info("%s: num_irq=%d, edge=0x%x\n",
-               intc->full_name, nr_irq, intr_mask);
+               intc->full_name, nr_irq, irqc->intr_mask);

-       write_fn = intc_write32;
-       read_fn = intc_read32;
+       irqc->read = intc_read32;
+       irqc->write = intc_write32;

        /*
         * Disable all external interrupts until they are
         * explicity requested.
         */
-       write_fn(0, intc_baseaddr + IER);
+       xintc_write(irqc, IER, 0);

        /* Acknowledge any pending interrupts just in case. */
-       write_fn(0xffffffff, intc_baseaddr + IAR);
+       xintc_write(irqc, IAR, 0xffffffff);

        /* Turn on the Master Enable. */
-       write_fn(MER_HIE | MER_ME, intc_baseaddr + MER);
-       if (!(read_fn(intc_baseaddr + MER) & (MER_HIE | MER_ME))) {
-               write_fn = intc_write32_be;
-               read_fn = intc_read32_be;
-               write_fn(MER_HIE | MER_ME, intc_baseaddr + MER);
+       xintc_write(irqc, MER, MER_HIE | MER_ME);
+       if (!(xintc_read(irqc, MER) & (MER_HIE | MER_ME))) {
+               irqc->read = intc_read32_be;
+               irqc->write = intc_write32_be;
+               xintc_write(irqc, MER, MER_HIE | MER_ME);
        }

-       /* Yeah, okay, casting the intr_mask to a void* is butt-ugly, but I'm
-        * lazy and Michal can clean it up to something nicer when he tests
-        * and commits this patch.  ~~gcl */
        root_domain = irq_domain_add_linear(intc, nr_irq, &xintc_irq_domain_ops,
-                                                       (void *)intr_mask);
+                                           irqc);

What if the domain allocation fails? You've now configured the HW for
something you can't use. What are the side effects? Hint: handle
everything that can fail first, and only then poke the HW.


Thanks for pointing it out. I'll add an error check.


        irq_set_default_host(root_domain);

        return 0;
+
+err_alloc:
+       xintc_irqc = NULL;
+       kfree(irqc);
+       return ret;
+
 }

 IRQCHIP_DECLARE(xilinx_intc, "xlnx,xps-intc-1.00.a", xilinx_intc_of_init);


Instead of posting 3 versions in 3 days, please take the time to
correctly address the comments, and review your own code before
re-posting it. Rushing to get it merged for 4.9 is really not the best
approach.

Apologies for the spam. Combination of some free time this week + window of 
opportunity.
To be fair, AFAIK, this driver has lived in arch/microblaze without receiving a 
full thorough
review by any irqchip maintainer.

Hence the various missing bits. e.g. the root_domain error check didn't exist 
before.
And I didn't see it.

Regards,
ZubairLK


Thanks,

        M.

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