From f8f912bf69a021c8cfff23e69e59c7c975a47c1a Mon Sep 17 00:00:00 2001 From: Neal Sidhwaney Date: Sat, 3 Jun 2023 02:00:23 -0400 Subject: [PATCH] wifi: brcmfmac: Detect corner error case earlier with log In brcmf_chip_recognition(), the return value from an MMIO read is interpreted as various fields without checking if it failed, which is harmless today, as the interpreted fields are checked for validity a few lines below. However, in corner cases (on my MacbookPro 14,1, sometimes after waking from sleep or soft reboot), when this happens, it causes the logging to be misleading, because the message indicates an unsupported chip type ("brcmfmac: brcmf_chip_recognition: chip backplane type 15 is not supported"). This patch detects this case slightly earlier and logs an appropriate message, with the same return result as is the case today. Signed-off-by: Neal Sidhwaney Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/20230603060021.57225-1-nealsid@gmail.com --- 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..2ef92ef25517 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; -- 2.34.1