In some corner cases, an I/O read can fail and return -1, and this patch detects this slightly earlier than is done today and logs an appropriate message. Signed-off-by: Neal Sidhwaney <nealsid@xxxxxxxxx> --- v2: Add const to variable holding error code & fix patch submission drivers/net/wireless/broadcom/brcm80211/brcmfmac/chip.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/chip.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/chip.c index 9f9bf08a70bb..39f3d913c1bc 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/chip.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/chip.c @@ -972,6 +972,7 @@ static int brcmf_chip_recognition(struct brcmf_chip_priv *ci) u32 regdata; u32 socitype; int ret; + const u32 READ_FAILED = 0xFFFFFFFF; /* Get CC core rev * Chipid is assume to be at offset 0 from SI_ENUM_BASE @@ -980,6 +981,11 @@ static int brcmf_chip_recognition(struct brcmf_chip_priv *ci) */ regdata = ci->ops->read32(ci->ctx, CORE_CC_REG(ci->pub.enum_base, chipid)); + if (regdata == READ_FAILED) { + brcmf_err("MMIO read failed: 0x%08x\n", regdata); + return -ENODEV; + } + ci->pub.chip = regdata & CID_ID_MASK; ci->pub.chiprev = (regdata & CID_REV_MASK) >> CID_REV_SHIFT; socitype = (regdata & CID_TYPE_MASK) >> CID_TYPE_SHIFT; -- 2.40.1