From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH -next] smsc911x: Fix crash seen if neither ACPI nor OF is configured or used Date: Wed, 26 Aug 2015 10:36:57 -0700 Message-ID: <55DDF939.9050209@roeck-us.net> References: <1439844336-21596-1-git-send-email-linux@roeck-us.net> <20150826170410.GP4215@atomide.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20150826170410.GP4215@atomide.com> Sender: linux-kernel-owner@vger.kernel.org To: Tony Lindgren Cc: Steve Glendinning , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jeremy Linton , linux-omap@vger.kernel.org List-Id: linux-omap@vger.kernel.org Hi Tony, On 08/26/2015 10:04 AM, Tony Lindgren wrote: > Hi, > > * Guenter Roeck [150817 13:48]: >> Commit 0b50dc4fc971 ("Convert smsc911x to use ACPI as well as DT") makes >> the call to smsc911x_probe_config() unconditional, and no longer fails if >> there is no device node. device_get_phy_mode() is called unconditionally, >> and if there is no phy node configured returns an error code. This error >> code is assigned to phy_interface, and interpreted elsewhere in the code >> as valid phy mode. This in turn causes qemu to crash when running a >> variant of realview_pb_defconfig. >> >> qemu: hardware error: lan9118_read: Bad reg 0x86 >> >> Fixes: 0b50dc4fc971 ("Convert smsc911x to use ACPI as well as DT") >> Cc: Jeremy Linton >> Cc Graeme Gregory >> Signed-off-by: Guenter Roeck >> --- >> drivers/net/ethernet/smsc/smsc911x.c | 7 ++++++- >> 1 file changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/net/ethernet/smsc/smsc911x.c b/drivers/net/ethernet/smsc/smsc911x.c >> index 0f21aa3bb537..34f97684506b 100644 >> --- a/drivers/net/ethernet/smsc/smsc911x.c >> +++ b/drivers/net/ethernet/smsc/smsc911x.c >> @@ -2367,12 +2367,17 @@ static const struct smsc911x_ops shifted_smsc911x_ops = { >> static int smsc911x_probe_config(struct smsc911x_platform_config *config, >> struct device *dev) >> { >> + int phy_interface; >> u32 width = 0; >> >> if (!dev) >> return -ENODEV; >> >> - config->phy_interface = device_get_phy_mode(dev); >> + phy_interface = device_get_phy_mode(dev); >> + if (phy_interface < 0) >> + return phy_interface; >> + >> + config->phy_interface = phy_interface; >> >> device_get_mac_address(dev, config->mac, ETH_ALEN); > > Looks like this change makes at least omap boards using smsc911x > fail with -22 for me in Linux next. > What do you see if you revert my patch ? It should assign -22, or its unsigned representation, to phy_interface, which isn't such a good idea either. > Do any of the the device tree configured smsc911x devices actually > have a phy configured? > Good question, and beats me. Looking into the original code, it didn't check for an error return from of_get_phy_mode() either, and thus _would_ dutifully assign the error code to phy_interface. Wonder how was this supposed to work to start with. I'll do some debugging and try to find out what exactly is going on. Guenter