Messages in this thread | | | From | Bartosz Golaszewski <> | Date | Thu, 19 Jul 2018 23:24:37 +0200 | Subject | Re: [PATCH 4/5] net: add support for nvmem to eth_platform_get_mac_address() |
| |
2018-07-19 19:47 GMT+02:00 Russell King - ARM Linux <linux@armlinux.org.uk>: > On Wed, Jul 18, 2018 at 06:10:34PM +0200, Bartosz Golaszewski wrote: >> @@ -544,6 +548,31 @@ int eth_platform_get_mac_address(struct device *dev, u8 *mac_addr) >> from = "arch callback"; >> } >> >> + if (!addr) { >> + nvmem = nvmem_cell_get(dev, "mac-address"); >> + if (IS_ERR(nvmem) && PTR_ERR(nvmem) == -EPROBE_DEFER) > > This is way too verbose. To quote Al Viro from earlier today: > > <viro> sigh... > <viro> if (IS_ERR(link) && PTR_ERR(link) == -EEXIST) > <viro> what the hell is wrong with if (link == ERR_PTR(-EEXIST))? > > I wonder why so many people haven't heard of pointer comparison... ;) > > IS_ERR(ERR_PTR(-EPROBE_DEFER)) is always true - if it wasn't, then > we'd be in for problems. > > So, if you're asserting that nvmem is ERR_PTR(-EPROBE_DEFER) then > there's no need to do the IS_ERR(nvmem) must also be true. Hence, a > simple pointer comparison is sufficient: > > if (nvmem == ERR_PTR(-EPROBE_DEFER)) > return -EPROBE_DEFER; >
Hi Russell,
this issue is gone now in v3 but thanks for the example - I somehow never thought about it.
Bart
| |