| Message ID | 55b78c1766da5b0d0d679f5eae3fb9fc74a6ceef.1323163127.git.LW@KARO-electronics.de |
|---|---|
| State | New |
| Headers | show |
Hi, Baruch Siach writes: > Hi Lothar, > > On Tue, Dec 06, 2011 at 11:27:13AM +0100, Lothar Waßmann wrote: > > When the MAC address is supplied via platform_data it should be OK as > > it is and should not be modified in case of a dual FEC setup. > > Also copying the MAC from platform_data to the single 'macaddr' > > variable will overwrite the MAC for the first interface in case of a > > dual FEC setup. > > > > Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de> > > --- > > drivers/net/ethernet/freescale/fec.c | 2 +- > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > > diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c > > index e2b5ce6..11534b9 100644 > > --- a/drivers/net/ethernet/freescale/fec.c > > +++ b/drivers/net/ethernet/freescale/fec.c > > @@ -818,7 +818,7 @@ static void __inline__ fec_get_mac(struct net_device *ndev) > > iap = (unsigned char *)FEC_FLASHMAC; > > #else > > if (pdata) > > - memcpy(iap, pdata->mac, ETH_ALEN); > > + iap = (unsigned char *)&pdata->mac; > > Since pdata might point to __initdata struct, you must hold a copy of its > content. > No. platform_data must be present during the life time of a driver using it and thus must never be __initdata! Lothar Waßmann
Hi, Shawn Guo writes: > On Tue, Dec 06, 2011 at 11:27:13AM +0100, Lothar Waßmann wrote: > > When the MAC address is supplied via platform_data it should be OK as > > it is and should not be modified in case of a dual FEC setup. > > Also copying the MAC from platform_data to the single 'macaddr' > > variable will overwrite the MAC for the first interface in case of a > > dual FEC setup. > > Hmm, I do not follow that. If 'macaddr' holds a valid mac address, > the code path has no chance to be hit at all. Otherwise, 'macaddr' > is just a place holder for copying mac address from pdata, in which > case the mac address will be fixed up at the end of the function for > dual FEC setup. > In case of dual FEC and MAC address provided by platform_data the first mac address will be copied to the 'macaddr' variable with no chance for the second interface to get its mac address assigned from platform_data too. Lothar Waßmann
Hi, Shawn Guo writes: > On Tue, Dec 06, 2011 at 02:44:44PM +0100, Lothar Waßmann wrote: > > Hi, > > > > Baruch Siach writes: > > > Hi Lothar, > > > > > > On Tue, Dec 06, 2011 at 11:27:13AM +0100, Lothar Waßmann wrote: > > > > When the MAC address is supplied via platform_data it should be OK as > > > > it is and should not be modified in case of a dual FEC setup. > > > > Also copying the MAC from platform_data to the single 'macaddr' > > > > variable will overwrite the MAC for the first interface in case of a > > > > dual FEC setup. > > > > > > > > Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de> > > > > --- > > > > drivers/net/ethernet/freescale/fec.c | 2 +- > > > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > > > > > > diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c > > > > index e2b5ce6..11534b9 100644 > > > > --- a/drivers/net/ethernet/freescale/fec.c > > > > +++ b/drivers/net/ethernet/freescale/fec.c > > > > @@ -818,7 +818,7 @@ static void __inline__ fec_get_mac(struct net_device *ndev) > > > > iap = (unsigned char *)FEC_FLASHMAC; > > > > #else > > > > if (pdata) > > > > - memcpy(iap, pdata->mac, ETH_ALEN); > > > > + iap = (unsigned char *)&pdata->mac; > > > > > > Since pdata might point to __initdata struct, you must hold a copy of its > > > content. > > > > > As iap will anyway be copied to ndev->dev_addr after that, it may still > be fine to take this patch, for obviously for different reason. > > > No. platform_data must be present during the life time of a driver > > using it and thus must never be __initdata! > > > Then we need to fix a lot of imx/mxc platform codes, mach-mx28evk.c > is the one for this case. > Nope. The platform_data provided there is only a template that is copied to kmalloc'ed memory by the mxs_add...() functions. With actual platform_data in init memory no driver built as module would work. Lothar Waßmann
On Tue, Dec 06, 2011 at 11:27:13AM +0100, Lothar Waßmann wrote: > When the MAC address is supplied via platform_data it should be OK as > it is and should not be modified in case of a dual FEC setup. > Also copying the MAC from platform_data to the single 'macaddr' > variable will overwrite the MAC for the first interface in case of a > dual FEC setup. Hmm, I do not follow that. If 'macaddr' holds a valid mac address, the code path has no chance to be hit at all. Otherwise, 'macaddr' is just a place holder for copying mac address from pdata, in which case the mac address will be fixed up at the end of the function for dual FEC setup. Regards, Shawn > > Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de> > --- > drivers/net/ethernet/freescale/fec.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c > index e2b5ce6..11534b9 100644 > --- a/drivers/net/ethernet/freescale/fec.c > +++ b/drivers/net/ethernet/freescale/fec.c > @@ -818,7 +818,7 @@ static void __inline__ fec_get_mac(struct net_device *ndev) > iap = (unsigned char *)FEC_FLASHMAC; > #else > if (pdata) > - memcpy(iap, pdata->mac, ETH_ALEN); > + iap = (unsigned char *)&pdata->mac; > #endif > } > > -- > 1.5.6.5
On Tue, Dec 06, 2011 at 02:44:44PM +0100, Lothar Waßmann wrote: > Hi, > > Baruch Siach writes: > > Hi Lothar, > > > > On Tue, Dec 06, 2011 at 11:27:13AM +0100, Lothar Waßmann wrote: > > > When the MAC address is supplied via platform_data it should be OK as > > > it is and should not be modified in case of a dual FEC setup. > > > Also copying the MAC from platform_data to the single 'macaddr' > > > variable will overwrite the MAC for the first interface in case of a > > > dual FEC setup. > > > > > > Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de> > > > --- > > > drivers/net/ethernet/freescale/fec.c | 2 +- > > > 1 files changed, 1 insertions(+), 1 deletions(-) > > > > > > diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c > > > index e2b5ce6..11534b9 100644 > > > --- a/drivers/net/ethernet/freescale/fec.c > > > +++ b/drivers/net/ethernet/freescale/fec.c > > > @@ -818,7 +818,7 @@ static void __inline__ fec_get_mac(struct net_device *ndev) > > > iap = (unsigned char *)FEC_FLASHMAC; > > > #else > > > if (pdata) > > > - memcpy(iap, pdata->mac, ETH_ALEN); > > > + iap = (unsigned char *)&pdata->mac; > > > > Since pdata might point to __initdata struct, you must hold a copy of its > > content. > > As iap will anyway be copied to ndev->dev_addr after that, it may still be fine to take this patch, for obviously for different reason. > No. platform_data must be present during the life time of a driver > using it and thus must never be __initdata! > Then we need to fix a lot of imx/mxc platform codes, mach-mx28evk.c is the one for this case.
On Wed, Dec 07, 2011 at 09:47:37AM +0100, Lothar Waßmann wrote: > Hi, > > Shawn Guo writes: > > On Tue, Dec 06, 2011 at 11:27:13AM +0100, Lothar Waßmann wrote: > > > When the MAC address is supplied via platform_data it should be OK as > > > it is and should not be modified in case of a dual FEC setup. > > > Also copying the MAC from platform_data to the single 'macaddr' > > > variable will overwrite the MAC for the first interface in case of a > > > dual FEC setup. > > > > Hmm, I do not follow that. If 'macaddr' holds a valid mac address, > > the code path has no chance to be hit at all. Otherwise, 'macaddr' > > is just a place holder for copying mac address from pdata, in which > > case the mac address will be fixed up at the end of the function for > > dual FEC setup. > > > In case of dual FEC and MAC address provided by platform_data the > first mac address will be copied to the 'macaddr' variable with no > chance for the second interface to get its mac address assigned from > platform_data too. > Indeed. So again other than subject, Acked-by: Shawn Guo <shawn.guo@linaro.org>
diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c index e2b5ce6..11534b9 100644 --- a/drivers/net/ethernet/freescale/fec.c +++ b/drivers/net/ethernet/freescale/fec.c @@ -818,7 +818,7 @@ static void __inline__ fec_get_mac(struct net_device *ndev) iap = (unsigned char *)FEC_FLASHMAC; #else if (pdata) - memcpy(iap, pdata->mac, ETH_ALEN); + iap = (unsigned char *)&pdata->mac; #endif }
When the MAC address is supplied via platform_data it should be OK as it is and should not be modified in case of a dual FEC setup. Also copying the MAC from platform_data to the single 'macaddr' variable will overwrite the MAC for the first interface in case of a dual FEC setup. Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de> --- drivers/net/ethernet/freescale/fec.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)