c changes when building without debug option configured: drivers/staging/brcm80211/brcmfmac/dhd_sdio.c: In function ‘dhdsdio_sdiod_drive_strength_init’: drivers/staging/brcm80211/brcmfmac/dhd_sdio.c:6366:3: error: ‘chn’ undeclared Cc: devel@linuxdriverproject.org Cc: linux-wireless@vger.kernel.org Cc: Brett Rudley Cc: Henry Ptasinski Cc: Roland Vossen Signed-off-by: Arend van Spriel Signed-off-by: Greg Kroah-Hartman ;.  x ̱