Re: [PATCH] usb: bdc: Remove duplicate error message in bdc_probe()

From: Tang Bin
Date: Mon Sep 28 2020 - 06:56:00 EST


Hi Balbi:

在 2020/9/28 17:40, Felipe Balbi 写道:
Hi,

Tang Bin <tangbin@xxxxxxxxxxxxxxxxxxxx> writes:
Hi Greg KH:

在 2020/9/27 21:45, Greg KH 写道:
On Sun, Sep 27, 2020 at 09:42:18PM +0800, Tang Bin wrote:
In this function, we don't need dev_err() message because
when something goes wrong, devm_platform_ioremap_resource()
can print an error message itself, so remove the redundant
one.

Signed-off-by: Zhang Shengju <zhangshengju@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Tang Bin <tangbin@xxxxxxxxxxxxxxxxxxxx>
---
drivers/usb/gadget/udc/bdc/bdc_core.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/usb/gadget/udc/bdc/bdc_core.c b/drivers/usb/gadget/udc/bdc/bdc_core.c
index 02a3a7746..9454f179e 100644
--- a/drivers/usb/gadget/udc/bdc/bdc_core.c
+++ b/drivers/usb/gadget/udc/bdc/bdc_core.c
@@ -508,10 +508,8 @@ static int bdc_probe(struct platform_device *pdev)
bdc->clk = clk;
bdc->regs = devm_platform_ioremap_resource(pdev, 0);
- if (IS_ERR(bdc->regs)) {
- dev_err(dev, "ioremap error\n");
+ if (IS_ERR(bdc->regs))
return -ENOMEM;
Why not return the error given to us?
Because when get ioremap failed, devm_platform_ioremap_resource() can
print error message

"dev_err(dev, "ioremap failed for resource %pR\n", res)" in it's called
function. So I think this's place's

dev_err(dev, "ioremap error\n") is redundant.
that's not what Greg point you at, though. Greg's concern is valid in
that instead of passing along the error within bdc->regs, you always
return -ENOMEM. OTW, your code should read like so:

if (IS_ERR(bdc->regs))
return PTR_ERR(bdc->regs);

Thanks for your explain,when I send the patch yesterday, my point is at dev_err(), and not aimed at IS_ERR() & PTR_ERR(),

if it's Greg's point, I will change this patch after his reply.


Thank you very much.

Tang Bin