Re: [Patch v5 04/12] irqchip: xilinx: Add support for parent intc

From: Zubair Lutfullah Kakakhel
Date: Tue Oct 25 2016 - 05:42:13 EST


Hi,

Thanks for the review.
Some comments in-line.

On 10/21/2016 10:48 AM, Marc Zyngier wrote:
On 17/10/16 17:52, Zubair Lutfullah Kakakhel wrote:
The MIPS based xilfpga platform has the following IRQ structure

Peripherals --> xilinx_intcontroller -> mips_cpu_int controller

Add support for the driver to chain the irq handler

Signed-off-by: Zubair Lutfullah Kakakhel <Zubair.Kakakhel@xxxxxxxxxx>

---
V4 -> V5
Rebased to v4.9-rc1
Missing curly braces

V3 -> V4
Clean up if/else when a parent is found
Pass irqchip structure to handler as data

V2 -> V3
Reused existing parent node instead of finding again.
Cleanup up handler based on review

V1 -> V2

No change
---
drivers/irqchip/irq-xilinx-intc.c | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/irqchip/irq-xilinx-intc.c b/drivers/irqchip/irq-xilinx-intc.c
index 45e5154..dbf8b0c 100644
--- a/drivers/irqchip/irq-xilinx-intc.c
+++ b/drivers/irqchip/irq-xilinx-intc.c
@@ -15,6 +15,7 @@
#include <linux/of_address.h>
#include <linux/io.h>
#include <linux/bug.h>
+#include <linux/of_irq.h>

/* No one else should require these constants, so define them locally here. */
#define ISR 0x00 /* Interrupt Status Register */
@@ -154,11 +155,23 @@ static int xintc_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hw)
.map = xintc_map,
};

+static void xil_intc_irq_handler(struct irq_desc *desc)
+{
+ u32 pending;
+
+ do {
+ pending = xintc_get_irq();
+ if (pending == -1U)
+ break;
+ generic_handle_irq(pending);
+ } while (true);

This is missing the chained_irq_enter()/exit() calls, which will lead to
races or lockups on the root irqchip.


I 'll fix it up in the next series.

+}
+
static int __init xilinx_intc_of_init(struct device_node *intc,
struct device_node *parent)
{
u32 nr_irq;
- int ret;
+ int ret, irq;
struct xintc_irq_chip *irqc;

if (xintc_irqc) {
@@ -221,7 +234,16 @@ static int __init xilinx_intc_of_init(struct device_node *intc,
goto err_alloc;
}

- irq_set_default_host(root_domain);
+ if (parent) {
+ irq = irq_of_parse_and_map(intc, 0);
+ if (irq)
+ irq_set_chained_handler_and_data(irq,
+ xil_intc_irq_handler,
+ irqc);
+

Shouldn't you return an error if irq is zero?


I'll add the following for the error case

pr_err("%s: Parent exists but interrupts property not defined\n" , __func__);
goto err_alloc;

Thanks
ZubairLK

+ } else {
+ irq_set_default_host(root_domain);
+ }

return 0;



Thanks,

M.