On Thu, Dec 28, 2017 at 10:05:26AM +0800, Cao Zou wrote: > Hi lorenzo: > > What do you think? I told you what I think about this specific issue and I share Marc's point of view. FYI, Gustavo's patches to achieve the end goal: https://patchwork.ozlabs.org/patch/854704/ > > Regards, > > czou > > > On 12/22/2017 05:35 PM, Marc Zyngier wrote: > >On 22/12/17 07:38, Cao Zou wrote: > >> > >>On 12/22/2017 11:04 AM, Cao Zou wrote: > >>> > >>>On 12/20/2017 12:20 AM, Lorenzo Pieralisi wrote: > >>>>On Mon, Dec 18, 2017 at 10:02:20AM +0800, Cao Zou wrote: > >>>>>On 12/16/2017 01:20 AM, Marc Zyngier wrote: > >>>>>>On 15/12/17 16:17, Lorenzo Pieralisi wrote: > >>>>>>>[+Marc] > >>>>>>> > >>>>>>>On Thu, Dec 14, 2017 at 10:21:23AM +0800, cao.zou@xxxxxxxxxxxxx > >>>>>>>wrote: > >>>>>>>>From: Zou Cao <cao.zou@xxxxxxxxxxxxx> > >>>>>>>> > >>>>>>>>When PCIE host setup, 32 MSI irq descriptions are created, but its > >>>>>>>>msi_desc is NULL, msi_desc is bound in MSI irq requested by PCI > >>>>>>>>device, > >>>>>>>>normally just part of MSI are used, for others not used MSI irqs, > >>>>>>>>its > >>>>>>>>msi_desc is NULL, it is dangerous for MSI irq mask when MSI irq > >>>>>>>>mask use > >>>>>>>>the msi_desc to mask irq without checking, normally not used MSI > >>>>>>>>irqs are > >>>>>>>>never masked, it looks fine, but in some specified case, such as > >>>>>>>>kdump, > >>>>>>>>machine_kexec_mask_interrupts will force to mask these not used > >>>>>>>>MSI irqs, > >>>>>>>>than a crash will happen with NULL msi_desc. it is necessary to > >>>>>>>>add check > >>>>>>>>of msi_desc in irqchip, if we still bind the msi_desc only in > >>>>>>>>irqs request > >>>>>>>>and mask MSI irq by msi_desc. > >>>>>>>> > >>>>>>>>Add dwc_pci_msi_mask/unmask_irq, so we can get a chance to check the > >>>>>>>>msi_desc. > >>>>>>>> > >>>>>>>>here is reproduced crash log in IMX7-SABER board with Intel 1030 > >>>>>>>>PCI, > >>>>>>>>when running kdump by "echo c > /proc/sysrq-trigger": > >>>>>>>> > >>>>>>>>sysrq: SysRq : Trigger a crash > >>>>>>>>Unable to handle kernel NULL pointer dereference at virtual > >>>>>>>>address 00000000 > >>>>>>>>pgd = 98ee1839 > >>>>>>>>[00000000] *pgd=00000000 > >>>>>>>>Internal error: Oops: 805 [#1] SMP ARM > >>>>>>>>Modules linked in: > >>>>>>>>CPU: 0 PID: 1370 Comm: sh Not tainted 4.15.0-rc3-00033-ga638349 #1 > >>>>>>>>Hardware name: Freescale i.MX7 Dual (Device Tree) > >>>>>>>>PC is at sysrq_handle_crash+0x50/0x98 > >>>>>>>>LR is at sysrq_handle_crash+0x50/0x98 > >>>>>>>><snip> > >>>>>>>>Backtrace: > >>>>>>>>[<c047a15c>] (msi_set_mask_bit) from [<c047a1f0>] > >>>>>>>>(pci_msi_mask_irq+0x14/0x18) > >>>>>>>>[<c047a1dc>] (pci_msi_mask_irq) from [<c011142c>] > >>>>>>>>(machine_crash_shutdown+0xd8/0x190) > >>>>>>>>[<c0111354>] (machine_crash_shutdown) from [<c01b2924>] > >>>>>>>>(__crash_kexec+0x5c/0xa0) > >>>>>>>>[<c01b28c8>] (__crash_kexec) from [<c01b29dc>] > >>>>>>>>(crash_kexec+0x74/0x80) > >>>>>>>>[<c01b2968>] (crash_kexec) from [<c010cfa4>] (die+0x220/0x358) > >>>>>>>>[<c010cd84>] (die) from [<c01169f0>] > >>>>>>>>(__do_kernel_fault.part.0+0x5c/0x7c) > >>>>>>>>[<c0116994>] (__do_kernel_fault.part.0) from [<c0116784>] > >>>>>>>>(do_page_fault+0x2cc/0x37c) > >>>>>>>>[<c01164b8>] (do_page_fault) from [<c0116970>] > >>>>>>>>(do_translation_fault+0xb0/0xbc) > >>>>>>>>[<c01168c0>] (do_translation_fault) from [<c010138c>] > >>>>>>>>(do_DataAbort+0x3c/0xbc) > >>>>>>>>[<c0101350>] (do_DataAbort) from [<c010d944>] (__dabt_svc+0x64/0xa0) > >>>>>>>>Exception stack(0xec08bdf8 to 0xec08be40) > >>>>>>>>bde0: > >>>>>>>>00000000 ec08be10 > >>>>>>>>be00: 00000000 00000000 00000000 00000001 00000063 00000000 > >>>>>>>>00000007 ec08a000 > >>>>>>>>be20: 00000000 ec08be5c ec08be48 ec08be48 c04c46b8 c04c46b8 > >>>>>>>>60060013 ffffffff > >>>>>>>>[<c04c4668>] (sysrq_handle_crash) from [<c04c4900>] > >>>>>>>>(__handle_sysrq+0xe0/0x254) > >>>>>>>>[<c04c4820>] (__handle_sysrq) from [<c04c4aec>] > >>>>>>>>(write_sysrq_trigger+0x78/0x90) > >>>>>>>>[<c04c4a74>] (write_sysrq_trigger) from [<c029148c>] > >>>>>>>>(proc_reg_write+0x68/0x90) > >>>>>>>>[<c0291424>] (proc_reg_write) from [<c0229ef8>] > >>>>>>>>(__vfs_write+0x34/0x12c) > >>>>>>>>[<c0229ec4>] (__vfs_write) from [<c022a16c>] (vfs_write+0xa8/0x16c) > >>>>>>>>[<c022a0c4>] (vfs_write) from [<c022a340>] (SyS_write+0x44/0x90) > >>>>>>>>[<c022a2fc>] (SyS_write) from [<c0108220>] > >>>>>>>>(ret_fast_syscall+0x0/0x28) > >>>>>>>> > >>>>>>>>Signed-off-by: Zou Cao <cao.zou@xxxxxxxxxxxxx> > >>>>>>>>--- > >>>>>>>> drivers/pci/dwc/pcie-designware-host.c | 24 > >>>>>>>>++++++++++++++++++++---- > >>>>>>>> 1 file changed, 20 insertions(+), 4 deletions(-) > >>>>>>>> > >>>>>>>>diff --git a/drivers/pci/dwc/pcie-designware-host.c > >>>>>>>>b/drivers/pci/dwc/pcie-designware-host.c > >>>>>>>>index 81e2157..485c4df 100644 > >>>>>>>>--- a/drivers/pci/dwc/pcie-designware-host.c > >>>>>>>>+++ b/drivers/pci/dwc/pcie-designware-host.c > >>>>>>>>@@ -45,12 +45,28 @@ static int dw_pcie_wr_own_conf(struct > >>>>>>>>pcie_port *pp, int where, int size, > >>>>>>>> return dw_pcie_write(pci->dbi_base + where, size, val); > >>>>>>>> } > >>>>>>>>+static void dwc_pci_msi_mask_irq(struct irq_data *data) > >>>>>>>>+{ > >>>>>>>>+ struct msi_desc *desc = irq_data_get_msi_desc(data); > >>>>>>>>+ > >>>>>>>>+ if (desc) > >>>>>>>>+ pci_msi_mask_irq(data); > >>>>>>>>+} > >>>>>>>>+ > >>>>>>>>+static void dwc_pci_msi_unmask_irq(struct irq_data *data) > >>>>>>>>+{ > >>>>>>>>+ struct msi_desc *desc = irq_data_get_msi_desc(data); > >>>>>>>>+ > >>>>>>>>+ if (desc) > >>>>>>>>+ pci_msi_unmask_irq(data); > >>>>>>>>+} > >>>>>>>>+ > >>>>>>>> static struct irq_chip dw_msi_irq_chip = { > >>>>>>>> .name = "PCI-MSI", > >>>>>>>>- .irq_enable = pci_msi_unmask_irq, > >>>>>>>>- .irq_disable = pci_msi_mask_irq, > >>>>>>>>- .irq_mask = pci_msi_mask_irq, > >>>>>>>>- .irq_unmask = pci_msi_unmask_irq, > >>>>>>>>+ .irq_enable = dwc_pci_msi_unmask_irq, > >>>>>>>>+ .irq_disable = dwc_pci_msi_mask_irq, > >>>>>>>>+ .irq_mask = dwc_pci_msi_mask_irq, > >>>>>>>>+ .irq_unmask = dwc_pci_msi_unmask_irq, > >>>>>>>> }; > >>>>>>>You have to CC me next time please. > >>>>>>> > >>>>>>>CC'ed Marc since he knows this code ways better than me and will > >>>>>>>help us find the right way of fixing it. > >>>>>>> > >>>>>>>I do not think that's a DWC-only problem - I see no reason why this > >>>>>>>would not affect other host bridges still relying on > >>>>>>>struct msi_controller (that we have to remove from the kernel). > >>>>>>> > >>>>>>>I do not think that this code is an actual fix but a plaster to > >>>>>>>paper over the issue - I will have a look into this as soon as > >>>>>>>possible to come up with an actual fix. > >>>>>>Yeah, this looks mad. The problem is that this seems to allocate > >>>>>>interrupts upfront, without being bound to an MSI. What could possibly > >>>>>>go wrong? And that's definitely not the only one (pci-tegra.c is one > >>>>>>fine example too). > >>>>>> > >>>>>>Until we take msi_controller and co to the backyard, how about the > >>>>>>following: > >>>>>> > >>>>>>>From b4aa5d20ee7b716795ac875e180f564fe0f52de6 Mon Sep > >>>>>>17 00:00:00 2001 > >>>>>>From: Marc Zyngier <marc.zyngier@xxxxxxx> > >>>>>>Date: Fri, 15 Dec 2017 17:10:14 +0000 > >>>>>>Subject: [PATCH] PCI/MSI: Don't try to mask/unmask an MSI that > >>>>>>doesn't have an > >>>>>> msi_desc > >>>>>> > >>>>>>There are a lot of MSI drivers out there that preallocate their > >>>>>>interrupts but not the corresponding MSIs. That's a prettty > >>>>>>naughty behaviour. On a kexec crash, we try to shut down all > >>>>>>the interrupts by calling the disable/mask methods. > >>>>>> > >>>>>>On these drivers, pci_msi_mask_irq() is unconditionnaly called, > >>>>>>leading to a crash. You wanted a crash kernel, right? > >>>>>> > >>>>>>So let's paper over the issue for the time being by detecting > >>>>>>the NULL msi_desc in msi_set_mask_bit(). Eventually, these drivers > >>>>>>will have to be fixed... > >>>>>> > >>>>>>Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> > >>>>>>--- > >>>>>> drivers/pci/msi.c | 3 +++ > >>>>>> 1 file changed, 3 insertions(+) > >>>>>> > >>>>>>diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c > >>>>>>index e06607167858..a5042cc8f3fc 100644 > >>>>>>--- a/drivers/pci/msi.c > >>>>>>+++ b/drivers/pci/msi.c > >>>>>>@@ -227,6 +227,9 @@ static void msi_set_mask_bit(struct irq_data > >>>>>>*data, u32 flag) > >>>>>> { > >>>>>> struct msi_desc *desc = irq_data_get_msi_desc(data); > >>>>>>+ if (WARN_ONCE(!desc, "NULL MSI descriptor!")) > >>>>>>+ return; > >>>>>>+ > >>>>>> if (desc->msi_attrib.is_msix) { > >>>>>> msix_mask_irq(desc, flag); > >>>>>> readl(desc->mask_base); /* Flush write to device */ > >>>>>For "if (WARN_ONCE(!desc, "NULL MSI descriptor!")", it is a good way, > >>>>>just one problem. how to fix the kexec/kdump? this WARN_ONCE can tell > >>>>>the pci dirver to fix the MIS bound problem, but in kexec/kdump, it > >>>>>will force to mask all MSI, it means that there are a lot of WARNINGS > >>>>>when running kexec/kdump. > >>>>There will be one warning as Marc said. Mind testing Marc's patch > >>>>and reporting the result on the mailing list please if you want > >>>>the issue fixed ? > >>>> > >>>>Thanks, > >>>>Lorenzo > >>>> > >>>Hi Lorenzo: > >>> Of course it can fix this issue, but warning will be seen in every > >>>time when running kdump > >>> > >>> > >>>root@nxp-imx7:~# echo c > /proc/sysrandom: crng init done > >>> > >>>sys/ sysrq-trigger sysvipc/ > >>>root@nxp-imx7:~# echo c > /proc/sysrq-trigger > >>>sysrq: SysRq : Trigger a crash > >>>Unable to handle kernel NULL pointer dereference at virtual address > >>>00000000 > >>>pgd = a9470000 > >>>[00000000] *pgd=a9474835, *pte=00000000, *ppte=00000000 > >>>Internal error: Oops: 817 [#1] PREEMPT SMP ARM > >>>Modules linked in: > >>>CPU: 0 PID: 369 Comm: sh Not tainted 4.12.14-yocto-standard+ #98 > >>>Hardware name: Freescale i.MX7 Dual (Device Tree) > >>>task: a86e5400 task.stack: a9438000 > >>>PC is at sysrq_handle_crash+0x30/0x3c > >>>LR is at sysrq_handle_crash+0x2c/0x3c > >>>pc : [<8059576c>] lr : [<80595768>] psr: 600e0013 > >>>sp : a9439eb8 ip : a9439eb8 fp : a9439ecc > >>>r10: 00000000 r9 : a9438000 r8 : 00000001 > >>>r7 : 00000000 r6 : 00000063 r5 : 00000007 r4 : 00000001 > >>>r3 : 00000000 r2 : a9439ea0 r1 : ab615434 r0 : 00000063 > >>>Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none > >>>Control: 10c5387d Table: a947006a DAC: 00000051 > >>>Process sh (pid: 369, stack limit = 0xa9438210) > >>>Stack: (0xa9439eb8 to 0xa943a000) > >>>9ea0: 8059573c 8106f41c > >>>9ec0: a9439eec a9439ed0 80595968 80595748 00000002 a8451444 a8451400 > >>>00000000 > >>>9ee0: a9439f04 a9439ef0 80595a78 805958c4 a9439f78 a8451444 a9439f2c > >>>a9439f08 > >>>9f00: 802c570c 80595a1c 802c5698 00000000 00000002 001042a8 a9439f78 > >>>001042a8 > >>>9f20: a9439f44 a9439f30 80268078 802c56a4 a9439f78 a901d6c0 a9439f74 > >>>a9439f48 > >>>9f40: 80269598 8026805c 80286cac 80286c1c 00000000 00000000 a901d6c0 > >>>a901d6c0 > >>>9f60: 00000002 001042a8 a9439fa4 a9439f78 8026982c 802694e4 00000000 > >>>00000000 > >>>9f80: 00000002 001042a8 76f19da8 00000004 80107f68 00000000 00000000 > >>>a9439fa8 > >>>9fa0: 80107d60 802697ec 00000002 001042a8 00000001 001042a8 00000002 > >>>00000000 > >>>9fc0: 00000002 001042a8 76f19da8 00000004 00000002 00000002 00000000 > >>>00000000 > >>>9fe0: 00000444 7e9d4980 76e466f0 76e9e41c 600e0010 00000001 3dbfa0e8 > >>>a39746c6 > >>>[<8059576c>] (sysrq_handle_crash) from [<80595968>] > >>>(__handle_sysrq+0xb0/0x158) > >>>[<80595968>] (__handle_sysrq) from [<80595a78>] > >>>(write_sysrq_trigger+0x68/0x78) > >>>[<80595a78>] (write_sysrq_trigger) from [<802c570c>] > >>>(proc_reg_write+0x74/0xa4) > >>>[<802c570c>] (proc_reg_write) from [<80268078>] (__vfs_write+0x28/0x48) > >>>[<80268078>] (__vfs_write) from [<80269598>] (vfs_write+0xc0/0x164) > >>>[<80269598>] (vfs_write) from [<8026982c>] (SyS_write+0x4c/0x8c) > >>>[<8026982c>] (SyS_write) from [<80107d60>] (ret_fast_syscall+0x0/0x3c) > >>>Code: e5834000 f57ff04e ebee0bee e3a03000 (e5c34000) > >>>------------[ cut here ]------------ > >>>WARNING: CPU: 0 PID: 369 at > >>>/export/disk1T/linux-yocto-4.12/drivers/pci/msi.c:230 > >>>msi_set_mask_bit+0x50/0xb0 > >>>NULL MSI descriptor! > >>>Modules linked in: > >>>CPU: 0 PID: 369 Comm: sh Not tainted 4.12.14-yocto-standard+ #98 > >>>Hardware name: Freescale i.MX7 Dual (Device Tree) > >>>[<80111a50>] (unwind_backtrace) from [<8010c110>] (show_stack+0x20/0x24) > >>>[<8010c110>] (show_stack) from [<804cb3dc>] (dump_stack+0x80/0xa0) > >>>[<804cb3dc>] (dump_stack) from [<8012a2f4>] (__warn+0xe4/0x114) > >>>[<8012a2f4>] (__warn) from [<8012a3f4>] (warn_slowpath_fmt+0x48/0x50) > >>>[<8012a3f4>] (warn_slowpath_fmt) from [<8052f380>] > >>>(msi_set_mask_bit+0x50/0xb0) > >>>[<8052f380>] (msi_set_mask_bit) from [<8052f41c>] > >>>(pci_msi_mask_irq+0x1c/0x20) > >>>[<8052f41c>] (pci_msi_mask_irq) from [<80110224>] > >>>(machine_crash_shutdown+0x108/0x174) > >>>[<80110224>] (machine_crash_shutdown) from [<801a7244>] > >>>(__crash_kexec+0x88/0xac) > >>>[<801a7244>] (__crash_kexec) from [<801a72d0>] (crash_kexec+0x68/0x78) > >>>[<801a72d0>] (crash_kexec) from [<8010c46c>] (die+0x358/0x47c) > >>>[<8010c46c>] (die) from [<8011ccbc>] > >>>(__do_kernel_fault.part.0+0x64/0x1f4) > >>>[<8011ccbc>] (__do_kernel_fault.part.0) from [<80ade250>] > >>>(do_page_fault+0x348/0x3d4) > >>>[<80ade250>] (do_page_fault) from [<801011f8>] (do_DataAbort+0x44/0xc4) > >>>[<801011f8>] (do_DataAbort) from [<80add5b8>] (__dabt_svc+0x58/0x80) > >>>Exception stack(0xa9439e68 to 0xa9439eb0) > >>>9e60: 00000063 ab615434 a9439ea0 00000000 00000001 > >>>00000007 > >>>9e80: 00000063 00000000 00000001 a9438000 00000000 a9439ecc a9439eb8 > >>>a9439eb8 > >>>9ea0: 80595768 8059576c 600e0013 ffffffff > >>>[<80add5b8>] (__dabt_svc) from [<8059576c>] > >>>(sysrq_handle_crash+0x30/0x3c) > >>>[<8059576c>] (sysrq_handle_crash) from [<80595968>] > >>>(__handle_sysrq+0xb0/0x158) > >>>[<80595968>] (__handle_sysrq) from [<80595a78>] > >>>(write_sysrq_trigger+0x68/0x78) > >>>[<80595a78>] (write_sysrq_trigger) from [<802c570c>] > >>>(proc_reg_write+0x74/0xa4) > >>>[<802c570c>] (proc_reg_write) from [<80268078>] (__vfs_write+0x28/0x48) > >>>[<80268078>] (__vfs_write) from [<80269598>] (vfs_write+0xc0/0x164) > >>>[<80269598>] (vfs_write) from [<8026982c>] (SyS_write+0x4c/0x8c) > >>>[<8026982c>] (SyS_write) from [<80107d60>] (ret_fast_syscall+0x0/0x3c) > >>>---[ end trace 7a853bb920d02801 ]--- > >>>Loading crashdump kernel... > >>>Bye! > >>>Booting Linux on physical CPU 0x0 > >>>Linux version 4.12.14-yocto-standard+ (czou@pek-czou-u14) (gcc version > >>>4.7.3 20130226 (prerelease) (crosstool-NG > >>>linaro-1.13.1-4.7-2013.03-20130313 - Linaro GCC 2013.03) ) #98 SMP > >>>PREEMPT Fri Dec 22 10:59:43 CST7 > >>>CPU: ARMv7 Processor [410fc075] revision 5 (ARMv7), cr=10c5387d > >>>CPU: div instructions available: patching division code > >>>CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache > >>>OF: fdt: Machine model: Freescale i.MX7 SabreSD Board > >>>OF: fdt: Ignoring memory range 0x80000000 - 0x88000000 > >>>Memory policy: Data cache writealloc > >>>OF: reserved mem: failed to allocate memory for node 'linux,cma' > >>>cma: Failed to reserve 320 MiB > >>>percpu: Embedded 17 pages/cpu @8fc75000 s38016 r8192 d23424 u69632 > >>>Built 1 zonelists in Zone order, mobility grouping on. Total pages: > >>>64706 > >>>Kernel command line: console=ttymxc0,115200 root=/dev/nfs ip=dhcp > >>>nfsroot=128.224.162.234:/var/lib/tftp/nfs/rootfs_imx7wrl10,v3 > >>>maxcpus=1 elfcorehdr=0x9cf00000 mem=261120K > >>>PID hash table entries: 1024 (order: 0, 4096 bytes) > >>>Dentry cache hash table entries: 32768 (order: 5, 131072 bytes) > >>>Inode-cache hash table entries: 16384 (order: 4, 65536 bytes) > >>>Memory: 241716K/261120K available (10240K kernel code, 778K rwdata, > >>>2388K rodata, 1024K init, 364K bss, 19404K reserved, 0K cma-reserved, > >>>0K highmem) > >>>Virtual kernel memory layout: > >>> vector : 0xffff0000 - 0xffff1000 ( 4 kB) > >>> fixmap : 0xffc00000 - 0xfff00000 (3072 kB) > >>> vmalloc : 0x90000000 - 0xff800000 (1784 MB) > >>> lowmem : 0x80000000 - 0x8ff00000 ( 255 MB) > >>> pkmap : 0x7fe00000 - 0x80000000 ( 2 MB) > >>> > >>>Regards, > >>>czou > >>> > >>Hi Marc: > >> I have a better way to fix it, just use dynamic allocate the irq_desc > >>in MSI irq setup, > >>remove the irq_desc allocate in dw_pcie_host_init, how do you think > >> > >>patch as follow: > >>diff --git a/drivers/pci/dwc/pcie-designware-host.c > >>b/drivers/pci/dwc/pcie-designware-host.c > >>index 5006d55..0426120 100644 > >>--- a/drivers/pci/dwc/pcie-designware-host.c > >>+++ b/drivers/pci/dwc/pcie-designware-host.c > >>@@ -168,8 +168,12 @@ static int assign_irq(int no_irqs, struct msi_desc > >>*desc, int *pos) > >> goto no_valid_irq; > >> > >> irq = irq_find_mapping(pp->irq_domain, pos0); > >>- if (!irq) > >>- goto no_valid_irq; > >>+ > >>+ if (!irq) { > >>+ irq = irq_create_mapping(pp->irq_domain, pos0); > >>+ if (!irq) > >>+ goto no_valid_irq; > >>+ } > >> > >> /* > >> * irq_create_mapping (called from dw_pcie_host_init) pre-allocates > >>@@ -408,9 +412,6 @@ int dw_pcie_host_init(struct pcie_port *pp) > >> ret = -ENXIO; > >> goto error; > >> } > >>- > >>- for (i = 0; i < MAX_MSI_IRQS; i++) > >>- irq_create_mapping(pp->irq_domain, i); > >> } else { > >> ret = pp->ops->msi_host_init(pp, > >>&dw_pcie_msi_chip); > >> if (ret < 0) > >> > >That's an option for *this* driver, but I'd rather you help Joao getting > >rid of this code altogether. It also ignores all the other drivers which > >suffer from the same defect. > > > >Joao, can you please point Cao to your existing patches? > > > >Thanks, > > > > M. >
