Re: [Intel-wired-lan] [PATCH net-next] ixgbe: Remove redundant self-assignments in ACI command execution

From: Dheeraj Reddy Jonnalagadda
Date: Tue Jan 14 2025 - 22:37:24 EST

On Tue, Jan 14, 2025 at 12:32:47PM +0000, Kwapulinski, Piotr wrote:
> >-----Original Message-----
> >From: Dheeraj Reddy Jonnalagadda <dheeraj.linuxdev@xxxxxxxxx>
> >Sent: Tuesday, January 14, 2025 1:23 AM
> >To: Kwapulinski, Piotr <piotr.kwapulinski@xxxxxxxxx>
> >Cc: andrew+netdev@xxxxxxx; Nguyen, Anthony L <anthony.l.nguyen@xxxxxxxxx>; davem@xxxxxxxxxxxxx; edumazet@xxxxxxxxxx; intel-wired-lan@xxxxxxxxxxxxxxxx; kuba@xxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx; pabeni@xxxxxxxxxx; Kitszel, Przemyslaw <przemyslaw.kitszel@xxxxxxxxx>; Swiatkowski, Michal <michal.swiatkowski@xxxxxxxxx>
> >Subject: Re: [Intel-wired-lan] [PATCH net-next] ixgbe: Remove redundant self-assignments in ACI command execution
> >
> >On Mon, Jan 13, 2025 at 03:23:31PM +0000, Kwapulinski, Piotr wrote:
> >> >[Intel-wired-lan] [PATCH net-next] ixgbe: Remove redundant
> >> >self-assignments in ACI command execution @ 2025-01-08 5:36 Dheeraj
> >> >Reddy Jonnalagadda
> >> > 2025-01-08 6:29 ` Michal Swiatkowski
> >> > 0 siblings, 1 reply; 2+ messages in thread
> >> >From: Dheeraj Reddy Jonnalagadda @ 2025-01-08 5:36 UTC (permalink /
> >> >raw)
> >> > To: anthony.l.nguyen, przemyslaw.kitszel
> >> > Cc: andrew+netdev, davem, edumazet, kuba, pabeni, intel-wired-lan,
> >> > netdev, linux-kernel, Dheeraj Reddy Jonnalagadda
> >> >
> >> >Remove redundant statements in ixgbe_aci_send_cmd_execute() where
> >> >raw_desc[i] is assigned to itself. These self-assignments have no
> >> >effect and can be safely removed.
> >> >
> >> >Fixes: 46761fd52a88 ("ixgbe: Add support for E610 FW Admin Command
> >> >Interface")
> >> >Closes:
> >> >https://scan7.scan.coverity.com/#/project-view/52337/11354?selectedIs
> >> >sue=1602757
> >> >Signed-off-by: Dheeraj Reddy Jonnalagadda
> >> >dheeraj.linuxdev@xxxxxxxxx<mailto:dheeraj.linuxdev@xxxxxxxxx>
> >> >---
> >> > drivers/net/ethernet/intel/ixgbe/ixgbe_e610.c | 2 --
> >> > 1 file changed, 2 deletions(-)
> >> >
> >> >diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_e610.c
> >> >b/drivers/net/ethernet/intel/ixgbe/ixgbe_e610.c
> >> >index 683c668672d6..408c0874cdc2 100644
> >> >--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_e610.c
> >> >+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_e610.c
> >> >@@ -145,7 +145,6 @@ static int ixgbe_aci_send_cmd_execute(struct ixgbe_hw *hw,
> >> > if ((hicr & IXGBE_PF_HICR_SV)) {
> >> > for (i = 0; i < IXGBE_ACI_DESC_SIZE_IN_DWORDS; i++) {
> >> > raw_desc[i] = IXGBE_READ_REG(hw, IXGBE_PF_HIDA(i));
> >> >- raw_desc[i] = raw_desc[i];
> >> > }
> >> > }
> >> >
> >> >@@ -153,7 +152,6 @@ static int ixgbe_aci_send_cmd_execute(struct ixgbe_hw *hw,
> >> > if ((hicr & IXGBE_PF_HICR_EV) && !(hicr & IXGBE_PF_HICR_C)) {
> >> > for (i = 0; i < IXGBE_ACI_DESC_SIZE_IN_DWORDS; i++) {
> >> > raw_desc[i] = IXGBE_READ_REG(hw, IXGBE_PF_HIDA_2(i));
> >> >- raw_desc[i] = raw_desc[i];
> >> > }
> >> > }
> >> >
> >>
> >> Hello,
> >> Possible solution may be as follows. I may also prepare the fix myself. Please let me know.
> >> Thanks,
> >> Piotr
> >>
> >> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_e610.c
> >> b/drivers/net/ethernet/intel/ixgbe/ixgbe_e610.c
> >> index e0f773c..af51e5a 100644
> >> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_e610.c
> >> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_e610.c
> >> @@ -113,7 +113,8 @@ static int ixgbe_aci_send_cmd_execute(struct
> >> ixgbe_hw *hw,
> >>
> >> /* Descriptor is written to specific registers */
> >> for (i = 0; i < IXGBE_ACI_DESC_SIZE_IN_DWORDS; i++)
> >> - IXGBE_WRITE_REG(hw, IXGBE_PF_HIDA(i), raw_desc[i]);
> >> + IXGBE_WRITE_REG(hw, IXGBE_PF_HIDA(i),
> >> + le32_to_cpu(raw_desc[i]));
> >>
> >> /* SW has to set PF_HICR.C bit and clear PF_HICR.SV and
> >> * PF_HICR_EV
> >> @@ -145,7 +146,7 @@ static int ixgbe_aci_send_cmd_execute(struct ixgbe_hw *hw,
> >> if ((hicr & IXGBE_PF_HICR_SV)) {
> >> for (i = 0; i < IXGBE_ACI_DESC_SIZE_IN_DWORDS; i++) {
> >> raw_desc[i] = IXGBE_READ_REG(hw, IXGBE_PF_HIDA(i));
> >> - raw_desc[i] = raw_desc[i];
> >> + raw_desc[i] = cpu_to_le32(raw_desc[i]);
> >> }
> >> }
> >>
> >> @@ -153,7 +154,7 @@ static int ixgbe_aci_send_cmd_execute(struct ixgbe_hw *hw,
> >> if ((hicr & IXGBE_PF_HICR_EV) && !(hicr & IXGBE_PF_HICR_C)) {
> >> for (i = 0; i < IXGBE_ACI_DESC_SIZE_IN_DWORDS; i++) {
> >> raw_desc[i] = IXGBE_READ_REG(hw, IXGBE_PF_HIDA_2(i));
> >> - raw_desc[i] = raw_desc[i];
> >> + raw_desc[i] = cpu_to_le32(raw_desc[i]);
> >> }
> >> }
> >>
> >
> >Hello Piotr,
> >
> >Thank you for suggesting the fix. I will prepare the new patch and send it over.
> >
> >-Dheeraj
>
> Hello,
> As a result of internal review from Przemek, it may be improved as follows:
>
> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_e610.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_e610.c
> index e0f773c..0ec944c 100644
> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_e610.c
> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_e610.c
> @@ -113,7 +113,8 @@ static int ixgbe_aci_send_cmd_execute(struct ixgbe_hw *hw,
>
> /* Descriptor is written to specific registers */
> for (i = 0; i < IXGBE_ACI_DESC_SIZE_IN_DWORDS; i++)
> - IXGBE_WRITE_REG(hw, IXGBE_PF_HIDA(i), raw_desc[i]);
> + IXGBE_WRITE_REG(hw, IXGBE_PF_HIDA(i),
> + cpu_to_le32(raw_desc[i]));
>
> /* SW has to set PF_HICR.C bit and clear PF_HICR.SV and
> * PF_HICR_EV
> @@ -145,7 +146,7 @@ static int ixgbe_aci_send_cmd_execute(struct ixgbe_hw *hw,
> if ((hicr & IXGBE_PF_HICR_SV)) {
> for (i = 0; i < IXGBE_ACI_DESC_SIZE_IN_DWORDS; i++) {
> raw_desc[i] = IXGBE_READ_REG(hw, IXGBE_PF_HIDA(i));
> - raw_desc[i] = raw_desc[i];
> + raw_desc[i] = le32_to_cpu(raw_desc[i]);
> }
> }
>
> @@ -153,7 +154,7 @@ static int ixgbe_aci_send_cmd_execute(struct ixgbe_hw *hw,
> if ((hicr & IXGBE_PF_HICR_EV) && !(hicr & IXGBE_PF_HICR_C)) {
> for (i = 0; i < IXGBE_ACI_DESC_SIZE_IN_DWORDS; i++) {
> raw_desc[i] = IXGBE_READ_REG(hw, IXGBE_PF_HIDA_2(i));
> - raw_desc[i] = raw_desc[i];
> + raw_desc[i] = le32_to_cpu(raw_desc[i]);
> }
> }
>
> Thank you,
> Piotr

Hello Piotr,

Thank you. I will update the patch accordingly and send it over.

-Dheeraj