[PATCH v2] net: stmmac: mmc: Remove duplicate mmc_rx crc

[PATCH v2] net: stmmac: mmc: Remove duplicate mmc_rx crc

[Abid Ali via B4 Relay]

From: Abid Ali <dev.taqnialabs@gmail.com>

MMC_XGMAC_RX_CRC_ERR is clear-on-read, and just a single read would
update the mmc_rx_crc_error counter.

[1] commit b6cdf09 ("net: stmmac: xgmac: Implement MMC counters").
The duplicate read appears to have been unintentionally introduced in
the intial MMC counter implementation. The databook does not mention
MMC_XGMAC_RX_CRC_ERR needing the additional read.

Fixes: b6cdf09 ("net: stmmac: xgmac: Implement MMC counters")
Signed-off-by: Abid Ali <dev.taqnialabs@gmail.com>
---
Changes in v2:
- Updated why the redundant read is removed based on feedback.
- Link to v1: https://lore.kernel.org/r/20260520-xgmac-mmc_rx_crc-cleanup-v1-1-7133f529859f@gmail.com
---
 drivers/net/ethernet/stmicro/stmmac/mmc_core.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/mmc_core.c b/drivers/net/ethernet/stmicro/stmmac/mmc_core.c
index 1b3b114e7..d81581dfa 100644
--- a/drivers/net/ethernet/stmicro/stmmac/mmc_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/mmc_core.c
@@ -479,8 +479,6 @@ static void dwxgmac_mmc_read(void __iomem *mmcaddr, struct stmmac_counters *mmc)
 			     &mmc->mmc_rx_multicastframe_g);
 	dwxgmac_read_mmc_reg(mmcaddr, MMC_XGMAC_RX_CRC_ERR,
 			     &mmc->mmc_rx_crc_error);
-	dwxgmac_read_mmc_reg(mmcaddr, MMC_XGMAC_RX_CRC_ERR,
-			     &mmc->mmc_rx_crc_error);
 	mmc->mmc_rx_run_error += readl(mmcaddr + MMC_XGMAC_RX_RUNT_ERR);
 	mmc->mmc_rx_jabber_error += readl(mmcaddr + MMC_XGMAC_RX_JABBER_ERR);
 	mmc->mmc_rx_undersize_g += readl(mmcaddr + MMC_XGMAC_RX_UNDER);

---
base-commit: 028ef9c96e96197026887c0f092424679298aae8
change-id: 20260520-xgmac-mmc_rx_crc-cleanup-afcea6faa8ab

Best regards,
-- 
Abid Ali <dev.taqnialabs@gmail.com>

Re: [PATCH v2] net: stmmac: mmc: Remove duplicate mmc_rx crc

[Andrew Lunn]

On Thu, May 21, 2026 at 04:32:46PM +0000, Abid Ali via B4 Relay wrote:
> From: Abid Ali <dev.taqnialabs@gmail.com>
> 
> MMC_XGMAC_RX_CRC_ERR is clear-on-read, and just a single read would
> update the mmc_rx_crc_error counter.
> 
> [1] commit b6cdf09 ("net: stmmac: xgmac: Implement MMC counters").
> The duplicate read appears to have been unintentionally introduced in
> the intial MMC counter implementation. The databook does not mention
> MMC_XGMAC_RX_CRC_ERR needing the additional read.

Thanks for the updated commit message.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>

    Andrew

Re: [PATCH v2] net: stmmac: mmc: Remove duplicate mmc_rx crc

[Abid Ali]

On Thu, May 21, 2026 at 20:44:53 +0200, Andrew Lunn wrote:
> Thanks for the updated commit message.
>
> Reviewed-by: Andrew Lunn <andrew@lunn.ch>

Much appreciated.

Should I send a v3 with the Reviewed-by trailer added ?

- Abid