* [PATCH] net/ice: fix statistics read error
@ 2025-11-07 7:43 Zhichao Zeng
2025-11-10 8:05 ` [PATCH v2] " Zhichao Zeng
0 siblings, 1 reply; 6+ messages in thread
From: Zhichao Zeng @ 2025-11-07 7:43 UTC (permalink / raw)
To: dev
Cc: stable, Zhichao Zeng, Bruce Richardson, Anatoly Burakov,
Ferruh Yigit, Wenzhuo Lu, Jeff Guo
The statistics contain 40 bits. The lower 32 bits are read first, followed
by the upper 8 bits.
In some cases, after reading the lower 32 bits, a carry occurs from the
lower bits, which causes the final statistics to be incorrect.
This commit fixes this issue.
Fixes: a37bde56314d ("net/ice: support statistics")
Cc: stable@dpdk.org
Signed-off-by: Zhichao Zeng <zhichaox.zeng@intel.com>
---
drivers/net/intel/ice/ice_ethdev.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/net/intel/ice/ice_ethdev.c b/drivers/net/intel/ice/ice_ethdev.c
index 513777e372..be08be0826 100644
--- a/drivers/net/intel/ice/ice_ethdev.c
+++ b/drivers/net/intel/ice/ice_ethdev.c
@@ -6036,10 +6036,19 @@ ice_stat_update_40(struct ice_hw *hw,
uint64_t *stat)
{
uint64_t new_data;
+ uint32_t lo, hi, lo2;
- new_data = (uint64_t)ICE_READ_REG(hw, loreg);
- new_data |= (uint64_t)(ICE_READ_REG(hw, hireg) & ICE_8_BIT_MASK) <<
- ICE_32_BIT_WIDTH;
+ lo = ICE_READ_REG(hw, loreg);
+ hi = ICE_READ_REG(hw, hireg);
+ lo2 = ICE_READ_REG(hw, loreg);
+
+ if (lo2 < lo) {
+ lo = ICE_READ_REG(hw, loreg);
+ hi = ICE_READ_REG(hw, hireg);
+ }
+
+ new_data = (uint64_t)lo;
+ new_data |= (uint64_t)(hi & ICE_8_BIT_MASK) << ICE_32_BIT_WIDTH;
if (!offset_loaded)
*offset = new_data;
--
2.34.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v2] net/ice: fix statistics read error
2025-11-07 7:43 [PATCH] net/ice: fix statistics read error Zhichao Zeng
@ 2025-11-10 8:05 ` Zhichao Zeng
2025-11-12 12:04 ` Bruce Richardson
2025-11-13 7:47 ` [PATCH v3] " Zhichao Zeng
0 siblings, 2 replies; 6+ messages in thread
From: Zhichao Zeng @ 2025-11-10 8:05 UTC (permalink / raw)
To: dev
Cc: stable, Zhichao Zeng, Bruce Richardson, Anatoly Burakov,
Jeff Guo, Ferruh Yigit, Wenzhuo Lu
The statistics contain 40 bits. The lower 32 bits are read first, followed
by the upper 8 bits.
In some cases, after reading the lower 32 bits, a carry occurs from
the lower bits, which causes the final statistics to be incorrect.
This commit fixes this issue.
Fixes: a37bde56314d ("net/ice: support statistics")
Cc: stable@dpdk.org
Signed-off-by: Zhichao Zeng <zhichaox.zeng@intel.com>
---
v2: replace single retries with loops
---
drivers/net/intel/ice/ice_ethdev.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/drivers/net/intel/ice/ice_ethdev.c b/drivers/net/intel/ice/ice_ethdev.c
index 4669eba7c7..016b25c63a 100644
--- a/drivers/net/intel/ice/ice_ethdev.c
+++ b/drivers/net/intel/ice/ice_ethdev.c
@@ -6351,10 +6351,16 @@ ice_stat_update_40(struct ice_hw *hw,
uint64_t *stat)
{
uint64_t new_data;
+ uint32_t lo_old, hi, lo;
- new_data = (uint64_t)ICE_READ_REG(hw, loreg);
- new_data |= (uint64_t)(ICE_READ_REG(hw, hireg) & ICE_8_BIT_MASK) <<
- ICE_32_BIT_WIDTH;
+ do {
+ lo_old = ICE_READ_REG(hw, loreg);
+ hi = ICE_READ_REG(hw, hireg);
+ lo = ICE_READ_REG(hw, loreg);
+ } while (lo_old > lo);
+
+ new_data = (uint64_t)lo;
+ new_data |= (uint64_t)(hi & ICE_8_BIT_MASK) << ICE_32_BIT_WIDTH;
if (!offset_loaded)
*offset = new_data;
@@ -6363,10 +6369,8 @@ ice_stat_update_40(struct ice_hw *hw,
*stat = new_data - *offset;
else
*stat = (uint64_t)((new_data +
- ((uint64_t)1 << ICE_40_BIT_WIDTH)) -
- *offset);
-
- *stat &= ICE_40_BIT_MASK;
+ ((uint64_t)1 << ICE_32_BIT_WIDTH))
+ - *offset);
}
/**
--
2.34.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] net/ice: fix statistics read error
2025-11-10 8:05 ` [PATCH v2] " Zhichao Zeng
@ 2025-11-12 12:04 ` Bruce Richardson
2025-11-13 7:18 ` 回复: " Zeng, ZhichaoX
2025-11-13 7:47 ` [PATCH v3] " Zhichao Zeng
1 sibling, 1 reply; 6+ messages in thread
From: Bruce Richardson @ 2025-11-12 12:04 UTC (permalink / raw)
To: Zhichao Zeng
Cc: dev, stable, Anatoly Burakov, Jeff Guo, Ferruh Yigit, Wenzhuo Lu
On Mon, Nov 10, 2025 at 04:05:14PM +0800, Zhichao Zeng wrote:
> The statistics contain 40 bits. The lower 32 bits are read first, followed
> by the upper 8 bits.
>
> In some cases, after reading the lower 32 bits, a carry occurs from
> the lower bits, which causes the final statistics to be incorrect.
>
> This commit fixes this issue.
>
> Fixes: a37bde56314d ("net/ice: support statistics")
> Cc: stable@dpdk.org
>
> Signed-off-by: Zhichao Zeng <zhichaox.zeng@intel.com>
>
> ---
> v2: replace single retries with loops
> ---
> drivers/net/intel/ice/ice_ethdev.c | 18 +++++++++++-------
> 1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/intel/ice/ice_ethdev.c b/drivers/net/intel/ice/ice_ethdev.c
> index 4669eba7c7..016b25c63a 100644
> --- a/drivers/net/intel/ice/ice_ethdev.c
> +++ b/drivers/net/intel/ice/ice_ethdev.c
> @@ -6351,10 +6351,16 @@ ice_stat_update_40(struct ice_hw *hw,
> uint64_t *stat)
> {
> uint64_t new_data;
> + uint32_t lo_old, hi, lo;
>
> - new_data = (uint64_t)ICE_READ_REG(hw, loreg);
> - new_data |= (uint64_t)(ICE_READ_REG(hw, hireg) & ICE_8_BIT_MASK) <<
> - ICE_32_BIT_WIDTH;
> + do {
> + lo_old = ICE_READ_REG(hw, loreg);
> + hi = ICE_READ_REG(hw, hireg);
> + lo = ICE_READ_REG(hw, loreg);
> + } while (lo_old > lo);
> +
> + new_data = (uint64_t)lo;
> + new_data |= (uint64_t)(hi & ICE_8_BIT_MASK) << ICE_32_BIT_WIDTH;
>
> if (!offset_loaded)
> *offset = new_data;
> @@ -6363,10 +6369,8 @@ ice_stat_update_40(struct ice_hw *hw,
> *stat = new_data - *offset;
> else
> *stat = (uint64_t)((new_data +
> - ((uint64_t)1 << ICE_40_BIT_WIDTH)) -
> - *offset);
> -
> - *stat &= ICE_40_BIT_MASK;
> + ((uint64_t)1 << ICE_32_BIT_WIDTH))
> + - *offset);
This part wasn't in v1, was it? It looks wrong to me, and the original code
looks correct. Given that offset and new_data should both be 40-bit
quantities, any wraparound would be at 40-bits rather than 32-bits no? Can
you explain why we would use a 32-bit shift here?
> }
>
> /**
> --
> 2.34.1
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* 回复: [PATCH v2] net/ice: fix statistics read error
2025-11-12 12:04 ` Bruce Richardson
@ 2025-11-13 7:18 ` Zeng, ZhichaoX
0 siblings, 0 replies; 6+ messages in thread
From: Zeng, ZhichaoX @ 2025-11-13 7:18 UTC (permalink / raw)
To: Richardson, Bruce
Cc: dev, stable, Burakov, Anatoly, Jeff Guo, Ferruh Yigit, Wenzhuo Lu
[-- Attachment #1: Type: text/plain, Size: 3089 bytes --]
Hi Bruce,
Thank you for your comments and you're right.
My apologies―since this patch was submitted some time ago, I lost track of the context when sending v2 and made an incorrect modification. I'll remove the erroneous code.
Regards
Zhichao
________________________________
发件人: Richardson, Bruce <bruce.richardson@intel.com>
已发送: 2025 年 11 月 12 日 星期三 20:04
收件人: Zeng, ZhichaoX <zhichaox.zeng@intel.com>
抄送: dev@dpdk.org <dev@dpdk.org>; stable@dpdk.org <stable@dpdk.org>; Burakov, Anatoly <anatoly.burakov@intel.com>; Jeff Guo <jia.guo@intel.com>; Ferruh Yigit <ferruh.yigit@amd.com>; Wenzhuo Lu <wenzhuo.lu@intel.com>
主题: Re: [PATCH v2] net/ice: fix statistics read error
On Mon, Nov 10, 2025 at 04:05:14PM +0800, Zhichao Zeng wrote:
> The statistics contain 40 bits. The lower 32 bits are read first, followed
> by the upper 8 bits.
>
> In some cases, after reading the lower 32 bits, a carry occurs from
> the lower bits, which causes the final statistics to be incorrect.
>
> This commit fixes this issue.
>
> Fixes: a37bde56314d ("net/ice: support statistics")
> Cc: stable@dpdk.org
>
> Signed-off-by: Zhichao Zeng <zhichaox.zeng@intel.com>
>
> ---
> v2: replace single retries with loops
> ---
> drivers/net/intel/ice/ice_ethdev.c | 18 +++++++++++-------
> 1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/net/intel/ice/ice_ethdev.c b/drivers/net/intel/ice/ice_ethdev.c
> index 4669eba7c7..016b25c63a 100644
> --- a/drivers/net/intel/ice/ice_ethdev.c
> +++ b/drivers/net/intel/ice/ice_ethdev.c
> @@ -6351,10 +6351,16 @@ ice_stat_update_40(struct ice_hw *hw,
> uint64_t *stat)
> {
> uint64_t new_data;
> + uint32_t lo_old, hi, lo;
>
> - new_data = (uint64_t)ICE_READ_REG(hw, loreg);
> - new_data |= (uint64_t)(ICE_READ_REG(hw, hireg) & ICE_8_BIT_MASK) <<
> - ICE_32_BIT_WIDTH;
> + do {
> + lo_old = ICE_READ_REG(hw, loreg);
> + hi = ICE_READ_REG(hw, hireg);
> + lo = ICE_READ_REG(hw, loreg);
> + } while (lo_old > lo);
> +
> + new_data = (uint64_t)lo;
> + new_data |= (uint64_t)(hi & ICE_8_BIT_MASK) << ICE_32_BIT_WIDTH;
>
> if (!offset_loaded)
> *offset = new_data;
> @@ -6363,10 +6369,8 @@ ice_stat_update_40(struct ice_hw *hw,
> *stat = new_data - *offset;
> else
> *stat = (uint64_t)((new_data +
> - ((uint64_t)1 << ICE_40_BIT_WIDTH)) -
> - *offset);
> -
> - *stat &= ICE_40_BIT_MASK;
> + ((uint64_t)1 << ICE_32_BIT_WIDTH))
> + - *offset);
This part wasn't in v1, was it? It looks wrong to me, and the original code
looks correct. Given that offset and new_data should both be 40-bit
quantities, any wraparound would be at 40-bits rather than 32-bits no? Can
you explain why we would use a 32-bit shift here?
> }
>
> /**
> --
> 2.34.1
>
[-- Attachment #2: Type: text/html, Size: 7262 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v3] net/ice: fix statistics read error
2025-11-10 8:05 ` [PATCH v2] " Zhichao Zeng
2025-11-12 12:04 ` Bruce Richardson
@ 2025-11-13 7:47 ` Zhichao Zeng
2025-11-13 8:42 ` Bruce Richardson
1 sibling, 1 reply; 6+ messages in thread
From: Zhichao Zeng @ 2025-11-13 7:47 UTC (permalink / raw)
To: dev
Cc: stable, Zhichao Zeng, Bruce Richardson, Anatoly Burakov,
Ferruh Yigit, Wenzhuo Lu, Jeff Guo
The statistics contain 40 bits. The lower 32 bits are read first, followed
by the upper 8 bits.
In some cases, after reading the lower 32 bits, a carry occurs from
the lower bits, which causes the final statistics to be incorrect.
This commit fixes this issue.
Fixes: a37bde56314d ("net/ice: support statistics")
Cc: stable@dpdk.org
Signed-off-by: Zhichao Zeng <zhichaox.zeng@intel.com>
---
v2: replace single retries with loops
v3: fix wrong logic
---
drivers/net/intel/ice/ice_ethdev.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/net/intel/ice/ice_ethdev.c b/drivers/net/intel/ice/ice_ethdev.c
index 4669eba7c7..5ec57ee2b0 100644
--- a/drivers/net/intel/ice/ice_ethdev.c
+++ b/drivers/net/intel/ice/ice_ethdev.c
@@ -6351,10 +6351,16 @@ ice_stat_update_40(struct ice_hw *hw,
uint64_t *stat)
{
uint64_t new_data;
+ uint32_t lo_old, hi, lo;
- new_data = (uint64_t)ICE_READ_REG(hw, loreg);
- new_data |= (uint64_t)(ICE_READ_REG(hw, hireg) & ICE_8_BIT_MASK) <<
- ICE_32_BIT_WIDTH;
+ do {
+ lo_old = ICE_READ_REG(hw, loreg);
+ hi = ICE_READ_REG(hw, hireg);
+ lo = ICE_READ_REG(hw, loreg);
+ } while (lo_old > lo);
+
+ new_data = (uint64_t)lo;
+ new_data |= (uint64_t)(hi & ICE_8_BIT_MASK) << ICE_32_BIT_WIDTH;
if (!offset_loaded)
*offset = new_data;
--
2.34.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v3] net/ice: fix statistics read error
2025-11-13 7:47 ` [PATCH v3] " Zhichao Zeng
@ 2025-11-13 8:42 ` Bruce Richardson
0 siblings, 0 replies; 6+ messages in thread
From: Bruce Richardson @ 2025-11-13 8:42 UTC (permalink / raw)
To: Zhichao Zeng
Cc: dev, stable, Anatoly Burakov, Ferruh Yigit, Wenzhuo Lu, Jeff Guo
On Thu, Nov 13, 2025 at 03:47:10PM +0800, Zhichao Zeng wrote:
> The statistics contain 40 bits. The lower 32 bits are read first, followed
> by the upper 8 bits.
>
> In some cases, after reading the lower 32 bits, a carry occurs from
> the lower bits, which causes the final statistics to be incorrect.
>
> This commit fixes this issue.
>
> Fixes: a37bde56314d ("net/ice: support statistics")
> Cc: stable@dpdk.org
>
> Signed-off-by: Zhichao Zeng <zhichaox.zeng@intel.com>
>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
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Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2025-11-07 7:43 [PATCH] net/ice: fix statistics read error Zhichao Zeng
2025-11-10 8:05 ` [PATCH v2] " Zhichao Zeng
2025-11-12 12:04 ` Bruce Richardson
2025-11-13 7:18 ` 回复: " Zeng, ZhichaoX
2025-11-13 7:47 ` [PATCH v3] " Zhichao Zeng
2025-11-13 8:42 ` Bruce Richardson
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