Clear the PCS_TX_SWING_FULL field mask before setting the new value
in PHY_CTRL5 register. Without clearing the mask first, the OR operation
could leave previously set bits, resulting in incorrect register
configuration.

Fixes: 63c85ad0cd81 ("phy: fsl-imx8mp-usb: add support for phy tuning")
Suggested-by: Leonid Segal <leonids@variscite.com>
Acked-by: Pierluigi Passaro <pierluigi.p@variscite.com>
Signed-off-by: Stefano Radaelli <stefano.r@variscite.com>
Reviewed-by: Xu Yang <xu.yang_2@nxp.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
---
v3:
- Fixed commit message line wrapping (75 chars)
v2:
- Improved commit subject as suggested by Fabio Estevam

 drivers/phy/freescale/phy-fsl-imx8mq-usb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
index ad8a55012e42..9458b6e5fcf4 100644
--- a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
+++ b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
@@ -504,6 +504,7 @@ static void imx8m_phy_tune(struct imx8mq_usb_phy *imx_phy)
 
 	if (imx_phy->pcs_tx_swing_full != PHY_TUNE_DEFAULT) {
 		value = readl(imx_phy->base + PHY_CTRL5);
+		value &= ~PHY_CTRL5_PCS_TX_SWING_FULL_MASK;
 		value |= FIELD_PREP(PHY_CTRL5_PCS_TX_SWING_FULL_MASK,
 				   imx_phy->pcs_tx_swing_full);
 		writel(value, imx_phy->base + PHY_CTRL5);

base-commit: ea1013c1539270e372fc99854bc6e4d94eaeff66
-- 
2.47.3

On Fri, 19 Dec 2025 17:09:12 +0100, Stefano Radaelli wrote:
> Clear the PCS_TX_SWING_FULL field mask before setting the new value
> in PHY_CTRL5 register. Without clearing the mask first, the OR operation
> could leave previously set bits, resulting in incorrect register
> configuration.
> 
> 

Applied, thanks!

[1/1] phy: fsl-imx8mq-usb: Clear the PCS_TX_SWING_FULL field before using it
      commit: 8becf9179a4b45104a1701010ed666b55bf4b3a6

Best regards,
-- 
~Vinod

On 12/19/25 5:09 PM, Stefano Radaelli wrote:
> Clear the PCS_TX_SWING_FULL field mask before setting the new value
> in PHY_CTRL5 register. Without clearing the mask first, the OR operation
> could leave previously set bits, resulting in incorrect register
> configuration.
> 
> Fixes: 63c85ad0cd81 ("phy: fsl-imx8mp-usb: add support for phy tuning")
> Suggested-by: Leonid Segal <leonids@variscite.com>
> Acked-by: Pierluigi Passaro <pierluigi.p@variscite.com>
> Signed-off-by: Stefano Radaelli <stefano.r@variscite.com>
> Reviewed-by: Xu Yang <xu.yang_2@nxp.com>
> Reviewed-by: Frank Li <Frank.Li@nxp.com>

Reviewed-by: Ahmad Fatoum <a.fatoum@pengutronix.de>

> ---
> v3:
> - Fixed commit message line wrapping (75 chars)
> v2:
> - Improved commit subject as suggested by Fabio Estevam
> 
>  drivers/phy/freescale/phy-fsl-imx8mq-usb.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> index ad8a55012e42..9458b6e5fcf4 100644
> --- a/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> +++ b/drivers/phy/freescale/phy-fsl-imx8mq-usb.c
> @@ -504,6 +504,7 @@ static void imx8m_phy_tune(struct imx8mq_usb_phy *imx_phy)
>  
>  	if (imx_phy->pcs_tx_swing_full != PHY_TUNE_DEFAULT) {
>  		value = readl(imx_phy->base + PHY_CTRL5);
> +		value &= ~PHY_CTRL5_PCS_TX_SWING_FULL_MASK;
>  		value |= FIELD_PREP(PHY_CTRL5_PCS_TX_SWING_FULL_MASK,
>  				   imx_phy->pcs_tx_swing_full);
>  		writel(value, imx_phy->base + PHY_CTRL5);
> 
> base-commit: ea1013c1539270e372fc99854bc6e4d94eaeff66

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On Fri, Dec 19, 2025 at 1:09 PM Stefano Radaelli
<stefano.radaelli21@gmail.com> wrote:
>
> Clear the PCS_TX_SWING_FULL field mask before setting the new value
> in PHY_CTRL5 register. Without clearing the mask first, the OR operation
> could leave previously set bits, resulting in incorrect register
> configuration.
>
> Fixes: 63c85ad0cd81 ("phy: fsl-imx8mp-usb: add support for phy tuning")
> Suggested-by: Leonid Segal <leonids@variscite.com>
> Acked-by: Pierluigi Passaro <pierluigi.p@variscite.com>
> Signed-off-by: Stefano Radaelli <stefano.r@variscite.com>
> Reviewed-by: Xu Yang <xu.yang_2@nxp.com>
> Reviewed-by: Frank Li <Frank.Li@nxp.com>

Reviewed-by: Fabio Estevam <festevam@gmail.com>