Thread (27 messages) 27 messages, 7 authors, 2022-02-10

Re: [PATCH 1/3] i2c: bcm2835: Use platform_get_irq() to get the interrupt

From: "Lad, Prabhakar" <prabhakar.csengg@gmail.com>
Date: 2021-12-18 22:44:46
Also in: linux-i2c, linux-renesas-soc, lkml

Hi Florian,

Thank you for the review.

On Sat, Dec 18, 2021 at 9:17 PM Florian Fainelli [off-list ref] wrote:


On 12/18/2021 8:52 AM, Lad Prabhakar wrote:
quoted
platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Just one nit below:
quoted
---
  drivers/i2c/busses/i2c-bcm2835.c | 11 ++++-------
  1 file changed, 4 insertions(+), 7 deletions(-)
diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c
index 37443edbf754..d63dec5f3cb1 100644
--- a/drivers/i2c/busses/i2c-bcm2835.c
+++ b/drivers/i2c/busses/i2c-bcm2835.c
@@ -402,7 +402,7 @@ static const struct i2c_adapter_quirks bcm2835_i2c_quirks = {
  static int bcm2835_i2c_probe(struct platform_device *pdev)
  {
      struct bcm2835_i2c_dev *i2c_dev;
-     struct resource *mem, *irq;
+     struct resource *mem;
      int ret;
      struct i2c_adapter *adap;
      struct clk *mclk;
@@ -452,12 +452,9 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
              return ret;
      }

-     irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-     if (!irq) {
-             dev_err(&pdev->dev, "No IRQ resource\n");
-             return -ENODEV;
-     }
-     i2c_dev->irq = irq->start;
+     i2c_dev->irq = platform_get_irq(pdev, 0);
+     if (i2c_dev->irq <= 0)
+             return i2c_dev->irq ? i2c_dev->irq : -ENXIO;
Why not just check for a negative return code and propagate it as is?
platform_get_irq() may return 0 said that we do get a splat in this
case and further request_irq() will fail so instead check it here.

Cheers,
Prabhakar

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