Messages in this thread | | | Subject | Re: stmmac: pci: Add dwmac support for Loongson | From | zhangqing <> | Date | Tue, 22 Jun 2021 10:17:14 +0800 |
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On 06/21/2021 11:51 PM, Colin Ian King wrote: > Hi, > > Static analysis by Coverity on today's linux-next has found an issue in > function loongson_dwmac_probe with the following commit: > > commit 30bba69d7db40e732d6c0aa6d4890c60d717e314 > Author: Qing Zhang <zhangqing@loongson.cn> > Date: Fri Jun 18 10:53:34 2021 +0800 > > stmmac: pci: Add dwmac support for Loongson > > The analysis is as follows: > > 110 plat->phy_interface = device_get_phy_mode(&pdev->dev); > > Enum compared against 0 > (NO_EFFECT) > unsigned_compare: This less-than-zero comparison of an > unsigned value is never true. plat->phy_interface < 0U. > > 111 if (plat->phy_interface < 0) > 112 dev_err(&pdev->dev, "phy_mode not found\n"); > > Enum plat->phy_interface is unsigned, so can't be negative and so the > comparison will always be false.
Hi,Colin
Thanks for your advice,
I see this judgment in stmmac_platform.c:
plat->phy_interface = device_get_phy_mode(&pdev->dev); if (plat->phy_interface < 0) return ERR_PTR(plat->phy_interface);
plat->interface = stmmac_of_get_mac_mode(np); if (plat->interface < 0)
> > A possible fix is to use int variable ret for the assignment and check: > > > ret = device_get_phy_mode(&pdev->dev); > if (ret < 0) > dev_err(&pdev->dev, "phy_mode not found\n"); > plat->phy_interface = ret; > > ..however, I think the dev_err may need handling too, e.g. > > ret = device_get_phy_mode(&pdev->dev); > if (ret < 0) { > dev_err(&pdev->dev, "phy_mode not found\n"); > ret = -ENODEV; > goto cleanup; /* needs to be written */ > } > plat->phy_interface = ret; > > Colin looks ok, but can be written to use of_get_phy_mode() , like this:
phy_interface_t interface; ret = of_get_phy_mode(pdev->dev->of_node, &interface); if (ret) return -EINVAL;
plat_dat->interface = interface; if(!plat->interface) dev_err(&pdev->dev, "Unsupported interface mode: %s", phy_modes(plat->interface));
Thanks
-Qing
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