PCI / PCIe: Introduce command line option to disable ARI
Subsystems (2)
PATCH 1/1 PCI / PCIe: Introduce command line option to disable ARI
From: Rafael J. Wysocki <[email protected]>
There are PCIe devices on the market that report ARI support but then fail to initialize correctly when ARI is actually used. This leads to situations in which kernels 2.6.34 and newer fail to handle systems where the previous kernels worked without any apparent problems. Unfortunately, it is currently unknown how many such devices are there.
For this reason, introduce a new kernel command line option, pci=noari, allowing users to disable PCIe ARI altogether if they see problems with PCIe device initialization.
--- drivers/pci/pci.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
drivers/pci/pci.c +6 -1
@@ -94,6 +94,9 @@ u8 pci_cache_line_size;*/ unsigned int pcibios_max_latency =255 ; +/* If set, the PCIe ARI capability will not be used. */ +static bool pcie_ari_disabled; +/** * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children * @bus: pointer to PCI bus structure to search
@@ -1922,7 +1925,7 @@ void pci_enable_ari(struct pci_dev *dev)u16 flags, ctrl;struct pci_dev *bridge; -if (!pci_is_pcie (dev) || dev->devfn) +if (pcie_ari_disabled || !pci_is_pcie (dev) || dev->devfn)return ; pos =pci_find_ext_capability (dev,PCI_EXT_CAP_ID_ARI );
@@ -3718,6 +3721,8 @@ static int __init pci_setup(char *str)pci_realloc (); }else if (!strcmp (str,"nodomains" )) {pci_no_domains (); + }else if (!strncmp (str,"noari" ,5 )) { + pcie_ari_disabled = true; }else if (!strncmp (str,"cbiosize=" ,9 )) { pci_cardbus_io_size =memparse (str +9 , &str); }else if (!strncmp (str,"cbmemsize=" ,10 )) {
Quoted 23 lines · Rafael J. Wysocki
From: Rafael J. Wysocki <[email protected]>
There are PCIe devices on the market that report ARI support but then fail to initialize correctly when ARI is actually used. This leads to situations in which kernels 2.6.34 and newer fail to handle systems where the previous kernels worked without any apparent problems. Unfortunately, it is currently unknown how many such devices are there.
For this reason, introduce a new kernel command line option, pci=noari, allowing users to disable PCIe ARI altogether if they see problems with PCIe device initialization.
Signed-off-by Rafael J. Wysocki <[email protected]>--- drivers/pci/pci.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)Index:
linux/drivers/pci/pci.c
===================================================================
drivers/pci/pci.c u8 pci_cache_line_size; · line 98
Quoted 5 lines
drivers/pci/pci.c +2
-0@@ -94,6 +94,9 @@ u8 pci_cache_line_size;*/ unsigned int pcibios_max_latency =255 ; +/* If set, the PCIe ARI capability will not be used. */ +static bool pcie_ari_disabled;
Please update Documentation/kernel-parameters.txt .
Signature · 1 line
~Randy
Quoted 28 lines · Randy Dunlap
Quoted 26 lines · Rafael J. Wysocki
From: Rafael J. Wysocki <[email protected]>
There are PCIe devices on the market that report ARI support but then fail to initialize correctly when ARI is actually used. This leads to situations in which kernels 2.6.34 and newer fail to handle systems where the previous kernels worked without any apparent problems. Unfortunately, it is currently unknown how many such devices are there.
For this reason, introduce a new kernel command line option, pci=noari, allowing users to disable PCIe ARI altogether if they see problems with PCIe device initialization.
Signed-off-by Rafael J. Wysocki <[email protected]>--- drivers/pci/pci.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)Index:
linux/drivers/pci/pci.c
===================================================================drivers/pci/pci.c +0
-0@@ -94,6 +94,9 @@ u8 pci_cache_line_size;*/ unsigned int pcibios_max_latency =255 ;
Quoted 5 lines
drivers/pci/pci.c u8 pci_cache_line_size; · line 98
Quoted 2 lines
drivers/pci/pci.c +2
-0+/* If set, the PCIe ARI capability will not be used. */ +static bool pcie_ari_disabled;Please update
Documentation/kernel-parameters.txt.
Ah, sorry for the omission, updated patch follows.
Thanks,
Rafael
---
From: Rafael J. Wysocki <[email protected]>
Subject: PCI / PCIe: Introduce command line option to disable ARI
There are PCIe devices on the market that report ARI support but then fail to initialize correctly when ARI is actually used. This leads to situations in which kernels 2.6.34 and newer fail to handle systems where the previous kernels worked without any apparent problems. Unfortunately, it is currently unknown how many such devices are there.
For this reason, introduce a new kernel command line option, pci=noari, allowing users to disable PCIe ARI altogether if they see problems with PCIe device initialization.
--- Documentation/kernel-parameters.txt | 1 + drivers/pci/pci.c | 7 ++++++- 2 files changed, 7 insertions(+), 1 deletion(-)
drivers/pci/pci.c +6 -1
@@ -94,6 +94,9 @@ u8 pci_cache_line_size;*/ unsigned int pcibios_max_latency =255 ; +/* If set, the PCIe ARI capability will not be used. */ +static bool pcie_ari_disabled; +/** * pci_bus_max_busnr - returns maximum PCI bus number of given bus' children * @bus: pointer to PCI bus structure to search
@@ -1922,7 +1925,7 @@ void pci_enable_ari(struct pci_dev *dev)u16 flags, ctrl;struct pci_dev *bridge; -if (!pci_is_pcie (dev) || dev->devfn) +if (pcie_ari_disabled || !pci_is_pcie (dev) || dev->devfn)return ; pos =pci_find_ext_capability (dev,PCI_EXT_CAP_ID_ARI );
@@ -3718,6 +3721,8 @@ static int __init pci_setup(char *str)pci_realloc (); }else if (!strcmp (str,"nodomains" )) {pci_no_domains (); + }else if (!strncmp (str,"noari" ,5 )) { + pcie_ari_disabled = true; }else if (!strncmp (str,"cbiosize=" ,9 )) { pci_cardbus_io_size =memparse (str +9 , &str); }else if (!strncmp (str,"cbmemsize=" ,10 )) {
Documentation/kernel-parameters.txt +1 -0
@@ -2111,6 +2111,7 @@ bytes respectively. Such letter suffixes on: Turn ECRC on. realloc reallocate PCI resources if allocations done by BIOS are erroneous. + noari do not use PCIe ARI. pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power Management.