Re: [PATCH][next] USB: EHCI: ehci-mv: fix less than zero comparisonof an unsigned int

From: Tang Bin
Date: Fri May 15 2020 - 19:22:56 EST


Hi Alan & Colinï

On 2020/5/16 1:21, Alan Stern wrote:
On Fri, May 15, 2020 at 05:54:53PM +0100, Colin King wrote:
From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

The comparison of hcd->irq to less than zero for an error check will
never be true because hcd->irq is an unsigned int. Fix this by
assigning the int retval to the return of platform_get_irq and checking
this for the -ve error condition and assigning hcd->irq to retval.

Addresses-Coverity: ("Unsigned compared against 0")
Fixes: c856b4b0fdb5 ("USB: EHCI: ehci-mv: fix error handling in mv_ehci_probe()")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
Thanks to Coverity for spotting this. Any reason why it didn't spot
exactly the same mistake in the ohci-da8xx.c driver?

I just looked at the code and wondered whether it would be more appropriate to modify the header file "hcd.h". Since 'irq' might be an negative, why not just modify the variables in the 'struct usb_hcd', 'unsigned int irq'--> 'int irq'? After all, it's a public one.

Thanks,

Tang Bin