* [Update][PATCH] PCI: Document PCIE BUS MPS parameters
@ 2013-01-23 12:28 Yijing Wang
2013-01-23 23:39 ` Randy Dunlap
0 siblings, 1 reply; 5+ messages in thread
From: Yijing Wang @ 2013-01-23 12:28 UTC (permalink / raw)
To: Rob Landley, Bjorn Helgaas
Cc: linux-doc, linux-kernel, Jon Mason, linux-pci, Andrew Murray,
Hanjun Guo, jiang.liu, Yijing Wang
Document PCIE BUS MPS parameters pcie_bus_tune_off, pcie_bus_safe,
pcie_bus_peer2peer, pcie_bus_perf into Documentation/kernel-parameters.txt.
These parameters were introduced by Jon Mason <mason@myri.com> at
commit 5f39e6705 and commit b03e7495a8. Document these into
kernel-parameters.txt can help users to understand and use the parameters.
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
---
Documentation/kernel-parameters.txt | 15 +++++++++++++++
1 files changed, 15 insertions(+), 0 deletions(-)
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 363e348..1fb269b 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2227,6 +2227,21 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
This sorting is done to get a device
order compatible with older (<= 2.4) kernels.
nobfsort Don't sort PCI devices into breadth-first order.
+ pcie_bus_tune_off Disable PCI-E MPS turning and using
+ the BIOS configured MPS defaults.
+ pcie_bus_safe Use the smallest common denominator MPS
+ of the entire tree below a root complex for every device
+ on that fabric. Can avoid inconsistent mps problem caused
+ by hotplug.
+ pcie_bus_perf Configure pcie device MPS to the largest allowable
+ MPS based on its parent bus. And also set MRRS to the
+ largest supported value but cannot be configured larger
+ than the MPS the device or the bus can support for Max
+ performance.
+ pcie_bus_peer2peer Make the system wide MPS the smallest
+ possible value (128B).This configuration could prevent it
+ from working by having the MPS on one root port different
+ than the MPS on another.
cbiosize=nn[KMG] The fixed amount of bus space which is
reserved for the CardBus bridge's IO window.
The default value is 256 bytes.
--
1.7.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [Update][PATCH] PCI: Document PCIE BUS MPS parameters
2013-01-23 12:28 [Update][PATCH] PCI: Document PCIE BUS MPS parameters Yijing Wang
@ 2013-01-23 23:39 ` Randy Dunlap
2013-01-24 1:55 ` Yijing Wang
0 siblings, 1 reply; 5+ messages in thread
From: Randy Dunlap @ 2013-01-23 23:39 UTC (permalink / raw)
To: Yijing Wang
Cc: Rob Landley, Bjorn Helgaas, linux-doc, linux-kernel, Jon Mason,
linux-pci, Andrew Murray, Hanjun Guo, jiang.liu
On 01/23/13 04:28, Yijing Wang wrote:
> Document PCIE BUS MPS parameters pcie_bus_tune_off, pcie_bus_safe,
> pcie_bus_peer2peer, pcie_bus_perf into Documentation/kernel-parameters.txt.
> These parameters were introduced by Jon Mason <mason@myri.com> at
> commit 5f39e6705 and commit b03e7495a8. Document these into
> kernel-parameters.txt can help users to understand and use the parameters.
>
> Signed-off-by: Yijing Wang <wangyijing@huawei.com>
> ---
> Documentation/kernel-parameters.txt | 15 +++++++++++++++
> 1 files changed, 15 insertions(+), 0 deletions(-)
>
> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
> index 363e348..1fb269b 100644
> --- a/Documentation/kernel-parameters.txt
> +++ b/Documentation/kernel-parameters.txt
> @@ -2227,6 +2227,21 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
> This sorting is done to get a device
> order compatible with older (<= 2.4) kernels.
> nobfsort Don't sort PCI devices into breadth-first order.
> + pcie_bus_tune_off Disable PCI-E MPS turning and using
> + the BIOS configured MPS defaults.
BIOS-configured
> + pcie_bus_safe Use the smallest common denominator MPS
> + of the entire tree below a root complex for every device
> + on that fabric. Can avoid inconsistent mps problem caused
s/mps/MPS/
i.e., use "MPS" consistently.
> + by hotplug.
> + pcie_bus_perf Configure pcie device MPS to the largest allowable
> + MPS based on its parent bus. And also set MRRS to the
"And also" is redundant. Just say Also.
What is (are) MRRS?
> + largest supported value but cannot be configured larger
> + than the MPS the device or the bus can support for Max
> + performance.
> + pcie_bus_peer2peer Make the system wide MPS the smallest
system-wide
> + possible value (128B).This configuration could prevent it
^ Space before "This"
> + from working by having the MPS on one root port different
> + than the MPS on another.
> cbiosize=nn[KMG] The fixed amount of bus space which is
> reserved for the CardBus bridge's IO window.
> The default value is 256 bytes.
>
--
~Randy
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Update][PATCH] PCI: Document PCIE BUS MPS parameters
2013-01-23 23:39 ` Randy Dunlap
@ 2013-01-24 1:55 ` Yijing Wang
2013-01-24 2:02 ` Randy Dunlap
0 siblings, 1 reply; 5+ messages in thread
From: Yijing Wang @ 2013-01-24 1:55 UTC (permalink / raw)
To: Randy Dunlap
Cc: Rob Landley, Bjorn Helgaas, linux-doc, linux-kernel, Jon Mason,
linux-pci, Andrew Murray, Hanjun Guo, jiang.liu
Hi Randy,
Thanks for your review and comments! please refer to inlined comments below.
On 2013/1/24 7:39, Randy Dunlap wrote:
> On 01/23/13 04:28, Yijing Wang wrote:
>> Document PCIE BUS MPS parameters pcie_bus_tune_off, pcie_bus_safe,
>> pcie_bus_peer2peer, pcie_bus_perf into Documentation/kernel-parameters.txt.
>> These parameters were introduced by Jon Mason <mason@myri.com> at
>> commit 5f39e6705 and commit b03e7495a8. Document these into
>> kernel-parameters.txt can help users to understand and use the parameters.
>>
>> Signed-off-by: Yijing Wang <wangyijing@huawei.com>
>> ---
>> Documentation/kernel-parameters.txt | 15 +++++++++++++++
>> 1 files changed, 15 insertions(+), 0 deletions(-)
>>
>> diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
>> index 363e348..1fb269b 100644
>> --- a/Documentation/kernel-parameters.txt
>> +++ b/Documentation/kernel-parameters.txt
>> @@ -2227,6 +2227,21 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
>> This sorting is done to get a device
>> order compatible with older (<= 2.4) kernels.
>> nobfsort Don't sort PCI devices into breadth-first order.
>> + pcie_bus_tune_off Disable PCI-E MPS turning and using
>> + the BIOS configured MPS defaults.
>
> BIOS-configured
Will update it.
>
>> + pcie_bus_safe Use the smallest common denominator MPS
>> + of the entire tree below a root complex for every device
>> + on that fabric. Can avoid inconsistent mps problem caused
>
> s/mps/MPS/
> i.e., use "MPS" consistently.
Will use mps consistently.
>
>> + by hotplug.
>> + pcie_bus_perf Configure pcie device MPS to the largest allowable
>> + MPS based on its parent bus. And also set MRRS to the
>
> "And also" is redundant. Just say Also.
Ok.
>
> What is (are) MRRS?
MRRS is "Max Read Request Size" and MPS is "Max Payload Size".
Need use "Max Read Request Size" instead of MRRS ?
>
>> + largest supported value but cannot be configured larger
>> + than the MPS the device or the bus can support for Max
>> + performance.
>> + pcie_bus_peer2peer Make the system wide MPS the smallest
>
> system-wide
Will update it.
>
>> + possible value (128B).This configuration could prevent it
>
> ^ Space before "This"
>
Thanks for reminder.
>> + from working by having the MPS on one root port different
>> + than the MPS on another.
>> cbiosize=nn[KMG] The fixed amount of bus space which is
>> reserved for the CardBus bridge's IO window.
>> The default value is 256 bytes.
>>
>
>
--
Thanks!
Yijing
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Update][PATCH] PCI: Document PCIE BUS MPS parameters
2013-01-24 1:55 ` Yijing Wang
@ 2013-01-24 2:02 ` Randy Dunlap
2013-01-24 2:20 ` Yijing Wang
0 siblings, 1 reply; 5+ messages in thread
From: Randy Dunlap @ 2013-01-24 2:02 UTC (permalink / raw)
To: Yijing Wang
Cc: Rob Landley, Bjorn Helgaas, linux-doc, linux-kernel, Jon Mason,
linux-pci, Andrew Murray, Hanjun Guo, jiang.liu
On 01/23/13 17:55, Yijing Wang wrote:
> Hi Randy,
> Thanks for your review and comments! please refer to inlined comments below.
>
> On 2013/1/24 7:39, Randy Dunlap wrote:
>> On 01/23/13 04:28, Yijing Wang wrote:
>>
>> What is (are) MRRS?
>
> MRRS is "Max Read Request Size" and MPS is "Max Payload Size".
> Need use "Max Read Request Size" instead of MRRS ?
Where is MRRS documented?
I would probably do it like so:
Also set MRRS (Max Read Request Size) to the ....
--
~Randy
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [Update][PATCH] PCI: Document PCIE BUS MPS parameters
2013-01-24 2:02 ` Randy Dunlap
@ 2013-01-24 2:20 ` Yijing Wang
0 siblings, 0 replies; 5+ messages in thread
From: Yijing Wang @ 2013-01-24 2:20 UTC (permalink / raw)
To: Randy Dunlap
Cc: Rob Landley, Bjorn Helgaas, linux-doc, linux-kernel, Jon Mason,
linux-pci, Andrew Murray, Hanjun Guo, jiang.liu
On 2013/1/24 10:02, Randy Dunlap wrote:
> On 01/23/13 17:55, Yijing Wang wrote:
>> Hi Randy,
>> Thanks for your review and comments! please refer to inlined comments below.
>>
>> On 2013/1/24 7:39, Randy Dunlap wrote:
>>> On 01/23/13 04:28, Yijing Wang wrote:
>
>>>
>>> What is (are) MRRS?
>>
>> MRRS is "Max Read Request Size" and MPS is "Max Payload Size".
>> Need use "Max Read Request Size" instead of MRRS ?
>
> Where is MRRS documented?
The description of MRRS can be found at PCIe Spec 2.0/3.0 7.8.4 Device Control Register.
>
> I would probably do it like so:
>
> Also set MRRS (Max Read Request Size) to the ....
Hmm, I will explain MPS and MRRS when they appear first time like,
pcie_bus_tune_off Disable PCIe MPS (Max Payload Size) turning and using
the BIOS-configured MPS defaults.
pcie_bus_perf ......Also set MRRS (Max Read Request Size) to the......
Thanks!
Yijing
>
--
Thanks!
Yijing
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2013-01-24 2:21 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2013-01-23 12:28 [Update][PATCH] PCI: Document PCIE BUS MPS parameters Yijing Wang
2013-01-23 23:39 ` Randy Dunlap
2013-01-24 1:55 ` Yijing Wang
2013-01-24 2:02 ` Randy Dunlap
2013-01-24 2:20 ` Yijing Wang
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