netdev - question about drivers/atm/iphase.c

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Date:   Fri, 3 Apr 2020 15:55:04 +0200 (CEST)
From:   Julia Lawall <julia.lawall@...ia.fr>
To:     3chas3@...il.com, linux-atm-general@...ts.sourceforge.net,
        netdev@...r.kernel.org
cc:     linux-kernel@...r.kernel.org, joe@...ches.com
Subject: question about drivers/atm/iphase.c

Hello,

The function ia_frontend_intr in iphase.c contains the following code:

        if (iadev->phy_type & FE_25MBIT_PHY) {
                status = ia_phy_read32(iadev, MB25_INTR_STATUS);
                iadev->carrier_detect = (status & MB25_IS_GSB) ? 1 : 0;
        } else if (iadev->phy_type & FE_DS3_PHY) {
                ia_phy_read32(iadev, SUNI_DS3_FRM_INTR_STAT);
                status = ia_phy_read32(iadev, SUNI_DS3_FRM_STAT);
                iadev->carrier_detect = (status & SUNI_DS3_LOSV) ? 0 : 1;
        } else if (iadev->phy_type & FE_E3_PHY) {
                ia_phy_read32(iadev, SUNI_E3_FRM_MAINT_INTR_IND);
                status = ia_phy_read32(iadev, SUNI_E3_FRM_FRAM_INTR_IND_STAT);
                iadev->carrier_detect = (status & SUNI_E3_LOS) ? 0 : 1;
        } else {
                status = ia_phy_read32(iadev, SUNI_RSOP_STATUS);
                iadev->carrier_detect = (status & SUNI_LOSV) ? 0 : 1;
        }

Specifically, the second if does a bit and with FE_DS3_PHY and the third
if does a bit and with FE_E3_PHY.  According to drivers/atm/iphase.h, the
former is 0x0080 and the latter is 0x0090.  Therefore, if the third test
would be true, it will never be reached.  How should the code be changed?

thanks,
julia