> -----Original Message----- > From: David Laight [mailto:david.lai...@aculab.com] > Sent: Tuesday, October 04, 2016 5:44 PM > To: Madalin-Cristian Bucur <madalin.bu...@nxp.com>; > netdev@vger.kernel.org > Cc: linuxdev.baldr...@gmail.com; linuxppc-...@lists.ozlabs.org; > da...@davemloft.net; linux-ker...@vger.kernel.org > Subject: RE: [net-next 08/13] fsl/fman: check pcsphy pointer before use > > From: Madalin Bucur > > Sent: 04 October 2016 08:33 > > Subject: [net-next 08/13] fsl/fman: check pcsphy pointer before use > .. > > --- a/drivers/net/ethernet/freescale/fman/fman_memac.c > > +++ b/drivers/net/ethernet/freescale/fman/fman_memac.c > > @@ -507,6 +507,9 @@ static void setup_sgmii_internal_phy(struct > fman_mac *memac, > > { > > u16 tmp_reg16; > > > > + if (WARN_ON(!memac->pcsphy)) > > + return; > > + > > Why? > > Either it can validly be NULL in which case you don't want the message. > Or it shouldn't be NULL in which case you need to find and fix the bug. > The later kernel OOPS will make the bug much easier to find. > > David
You can get into that situation if you have a broken device tree, state into which someone may get while trying to create the device tree for a new board. Avoiding a crash here allows the user to look at the device trees as seen by the kernel / add some debug code if needed. Madalin
