Hi Sergei:
On 2020/5/9 4:27, Sergei Shtylyov wrote:
On 05/08/2020 06:03 PM, Tang Bin wrote:
On Fri, May 08, 2020 at 07:44:53PM +0800, Tang Bin wrote:
The function ehci_mxc_drv_probe() does not perform sufficient error
checking after executing platform_get_irq(), thus fix it.
Fixes: 7e8d5cd93fa ("USB: Add EHCI support for MX27 and MX31 based boards")
Signed-off-by: Zhang Shengju <zhangshengju@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Tang Bin <tangbin@xxxxxxxxxxxxxxxxxxxx>
---
drivers/usb/host/ehci-mxc.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
index a1eb5ee77..a0b42ba59 100644
--- a/drivers/usb/host/ehci-mxc.c
+++ b/drivers/usb/host/ehci-mxc.c
@@ -50,6 +50,8 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
}
irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
<= ?
In the file 'drivers/base/platform.c'， the function platform_get_irq() is
explained and used as follows:
* Gets an IRQ for a platform device and prints an error message if
finding the
* IRQ fails. Device drivers should check the return value for errors so
as to
* not pass a negative integer value to the request_irq() APIs.
*
* Example:
* int irq = platform_get_irq(pdev, 0);
* if (irq < 0)
* return irq;
*
* Return: IRQ number on success, negative error number on failure.
And in my hardware experiment, even if I set the irq failed deliberately in
the DTS, the returned value is negative instead of zero.
Please read the thread at
https://lore.kernel.org/r/20200501224042.141366-1-helgaas%40kernel.org
for more details about this.
Great, It looks beautiful, finally someone took a knife to the file 'platform.c'.
I thought I did that already couple years ago, when returned 0 from platform_get_irq() could mean both IRQ # and error... :-)
Can you tell me what platform can returned 0? I want to do this test in
the hardware.
I have been studied this place for a long time, and don't know what platform can return 0, which made me curious.
So the example should be:
* int irq = platform_get_irq(pdev, 0);
* if (irq <= 0)
* return irq;
And you then return 0 (success) as if your probe() succeeded. Congratulations! :-P
Thanks,
Tang Bin
