Hi Greg, This fix is not required on 3.14. Fix was required to address an issue, introduced by the iommu_group_get_for_dev API in the PAMU driver code. Regards Varun > -----Original Message----- > From: Greg Kroah-Hartman [mailto:gregkh@xxxxxxxxxxxxxxxxxxx] > Sent: Saturday, October 04, 2014 3:00 AM > To: linux-kernel@xxxxxxxxxxxxxxx > Cc: Greg Kroah-Hartman; stable@xxxxxxxxxxxxxxx; Sethi Varun-B16395; Joerg > Roedel > Subject: [PATCH 3.14 104/238] iommu/fsl: Fix warning resulting from adding PCI > device twice > > 3.14-stable review patch. If anyone has any objections, please let me know. > > ------------------ > > From: Varun Sethi <Varun.Sethi@xxxxxxxxxxxxx> > > commit 5a9137a66b521d667236e95c307b92af532fe600 upstream. > > iommu_group_get_for_dev determines the iommu group for the PCI device > and adds the device to the group. > > In the PAMU driver we were again adding the device to the same group > without checking if the device already had an iommu group. This resulted in the > following warning. > > sysfs: cannot create duplicate filename > '/devices/ffe200000.pcie/pci0000:00/0000:00:00.0/iommu_group' > ------------[ cut here ]------------ > WARNING: at fs/sysfs/dir.c:31 > Modules linked in: > CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.17.0-rc3-00002-g7505cea-dirty > #126 > task: c0000001fe0a0000 ti: c0000001fe044000 task.ti: c0000001fe044000 > NIP: c00000000018879c LR: c000000000188798 CTR: c00000000001ea50 > REGS: c0000001fe047040 TRAP: 0700 Not tainted (3.17.0-rc3-00002-g7505cea- > dirty) > MSR: 0000000080029000 <CE,EE,ME> CR: 24ad8e22 XER: 20000000 > SOFTE: 1 > GPR00: c000000000188798 c0000001fe0472c0 c0000000009a52e0 > 0000000000000065 > GPR04: 0000000000000001 0000000000000000 3a30303a00000000 > 0000000027000000 > GPR08: 2f696f6d00000000 c0000000008d3830 c0000000009b3938 > c0000000009bb3d0 > GPR12: 0000000028ad8e24 c00000000fff4000 c00000000000205c > 0000000000000000 > GPR16: 0000000000000000 0000000000000000 0000000000000000 > 0000000000000000 > GPR20: 0000000000000000 0000000000000000 0000000000000000 > c0000000008a4c70 > GPR24: c0000000007e9010 c0000001fe0140a8 ffffffffffffffef 0000000000000001 > GPR28: c0000001fe22ebb8 c0000000007e9010 c00000000090bf10 > c0000001fe220000 NIP [c00000000018879c] .sysfs_warn_dup+0x74/0xa4 LR > [c000000000188798] .sysfs_warn_dup+0x70/0xa4 Call Trace: > [c0000001fe0472c0] [c000000000188798] .sysfs_warn_dup+0x70/0xa4 > (unreliable) [c0000001fe047350] [c000000000188d34] > .sysfs_do_create_link_sd.clone.2+0x168/0x174 > [c0000001fe047400] [c0000000004b3cf8] > .iommu_group_add_device+0x78/0x244 > [c0000001fe0474b0] [c0000000004b6964] .fsl_pamu_add_device+0x88/0x1a8 > [c0000001fe047570] [c0000000004b3960] .iommu_bus_notifier+0xdc/0x15c > [c0000001fe047600] [c000000000059848] .notifier_call_chain+0x8c/0xe8 > [c0000001fe0476a0] [c000000000059d04] > .__blocking_notifier_call_chain+0x58/0x84 > [c0000001fe047750] [c00000000036619c] .device_add+0x464/0x5c8 > [c0000001fe047820] [c000000000300ebc] .pci_device_add+0x14c/0x17c > [c0000001fe0478c0] [c000000000300fbc] .pci_scan_single_device+0xd0/0xf4 > [c0000001fe047970] [c00000000030104c] .pci_scan_slot+0x6c/0x18c > [c0000001fe047a10] [c00000000030226c] .pci_scan_child_bus+0x40/0x114 > [c0000001fe047ac0] [c000000000021974] .pcibios_scan_phb+0x240/0x2c8 > [c0000001fe047b70] [c00000000085a970] .pcibios_init+0x64/0xc8 > [c0000001fe047c00] [c000000000001884] .do_one_initcall+0xbc/0x224 > [c0000001fe047d00] [c000000000852d50] .kernel_init_freeable+0x14c/0x21c > [c0000001fe047db0] [c000000000002078] .kernel_init+0x1c/0xfa4 > [c0000001fe047e30] [c000000000000884] .ret_from_kernel_thread+0x58/0xd4 > Instruction dump: > 7c7f1b79 4182001c 7fe4fb78 7f83e378 38a01000 4bffc905 60000000 7c641b78 > e87e8008 7fa5eb78 48482ff5 60000000 <0fe00000> 7fe3fb78 4bf7bd39 60000000 > > Signed-off-by: Varun Sethi <Varun.Sethi@xxxxxxxxxxxxx> > Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > --- > drivers/iommu/fsl_pamu_domain.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > --- a/drivers/iommu/fsl_pamu_domain.c > +++ b/drivers/iommu/fsl_pamu_domain.c > @@ -1050,7 +1050,7 @@ static int fsl_pamu_add_device(struct de > struct iommu_group *group = NULL; > struct pci_dev *pdev; > const u32 *prop; > - int ret, len; > + int ret = 0, len; > > /* > * For platform devices we allocate a separate group for @@ -1073,7 > +1073,13 @@ static int fsl_pamu_add_device(struct de > if (!group || IS_ERR(group)) > return PTR_ERR(group); > > - ret = iommu_group_add_device(group, dev); > + /* > + * Check if device has already been added to an iommu group. > + * Group could have already been created for a PCI device in > + * the iommu_group_get_for_dev path. > + */ > + if (!dev->iommu_group) > + ret = iommu_group_add_device(group, dev); > > iommu_group_put(group); > return ret; ��.n��������+%������w��{.n�����������ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f