[PATCH] phy: exynos5-usbdrd: fix USB 2.0 HS PHY tuning values for Exynos7870

[PATCH] phy: exynos5-usbdrd: fix USB 2.0 HS PHY tuning values for Exynos7870

[Łukasz Lebiedziński]

The existing PHYPARAM0 tuning values for Exynos7870 are incorrect,
causing the USB 2.0 PHY to fail high-speed negotiation and fall back
to full-speed (12Mbps) operation.

Fix TXVREFTUNE (transmitter voltage reference) from 14 to 3,
TXRESTUNE (transmitter impedance) from 3 to 2, and SQRXTUNE
(squelch threshold) from 6 to 5. Also explicitly set
TXPREEMPPULSETUNE to 0, which was previously missing from the
tuning table despite being included in the register mask.

All values are derived from the vendor kernel for the Samsung
Galaxy A6 (SM-A600FN), as no public hardware documentation is
available for the Exynos7870 USB DRD PHY. With these corrections,
the PHY successfully negotiates high-speed (480Mbps) operation.

Fixes: 588d5d20ca8d ("phy: exynos5-usbdrd: add exynos7870 USBDRD support")
Cc: stable@vger.kernel.org
Tested-by: Łukasz Lebiedziński <kernel@lvkasz.us>
Tested-by: Kaustabh Chakraborty <kauschluss@disroot.org>
Signed-off-by: Łukasz Lebiedziński <kernel@lvkasz.us>
---
 drivers/phy/samsung/phy-exynos5-usbdrd.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/phy/samsung/phy-exynos5-usbdrd.c b/drivers/phy/samsung/phy-exynos5-usbdrd.c
index 5a181cb4597e..8711a3b62c8e 100644
--- a/drivers/phy/samsung/phy-exynos5-usbdrd.c
+++ b/drivers/phy/samsung/phy-exynos5-usbdrd.c
@@ -1958,13 +1958,14 @@ const struct exynos5_usbdrd_phy_tuning exynos7870_tunes_utmi_postinit[] = {
 			      PHYPARAM0_TXPREEMPAMPTUNE | PHYPARAM0_TXHSXVTUNE |
 			      PHYPARAM0_TXFSLSTUNE | PHYPARAM0_SQRXTUNE |
 			      PHYPARAM0_OTGTUNE | PHYPARAM0_COMPDISTUNE),
-			     (FIELD_PREP_CONST(PHYPARAM0_TXVREFTUNE, 14) |
+			     (FIELD_PREP_CONST(PHYPARAM0_TXVREFTUNE, 3) |
 			      FIELD_PREP_CONST(PHYPARAM0_TXRISETUNE, 1) |
-			      FIELD_PREP_CONST(PHYPARAM0_TXRESTUNE, 3) |
+			      FIELD_PREP_CONST(PHYPARAM0_TXRESTUNE, 2) |
+			      FIELD_PREP_CONST(PHYPARAM0_TXPREEMPPULSETUNE, 0) |
 			      FIELD_PREP_CONST(PHYPARAM0_TXPREEMPAMPTUNE, 0) |
 			      FIELD_PREP_CONST(PHYPARAM0_TXHSXVTUNE, 0) |
 			      FIELD_PREP_CONST(PHYPARAM0_TXFSLSTUNE, 3) |
-			      FIELD_PREP_CONST(PHYPARAM0_SQRXTUNE, 6) |
+			      FIELD_PREP_CONST(PHYPARAM0_SQRXTUNE, 5) |
 			      FIELD_PREP_CONST(PHYPARAM0_OTGTUNE, 2) |
 			      FIELD_PREP_CONST(PHYPARAM0_COMPDISTUNE, 3))),
 	PHY_TUNING_ENTRY_LAST

base-commit: caf08514bbee0736c31d8d4f406e3415cdf726bb
-- 
2.53.0

Re: [PATCH] phy: exynos5-usbdrd: fix USB 2.0 HS PHY tuning values for Exynos7870

[Krzysztof Kozlowski]

On 06/04/2026 09:05, Łukasz Lebiedziński wrote:
> The existing PHYPARAM0 tuning values for Exynos7870 are incorrect,
> causing the USB 2.0 PHY to fail high-speed negotiation and fall back
> to full-speed (12Mbps) operation.
> 
> Fix TXVREFTUNE (transmitter voltage reference) from 14 to 3,
> TXRESTUNE (transmitter impedance) from 3 to 2, and SQRXTUNE
> (squelch threshold) from 6 to 5. Also explicitly set
> TXPREEMPPULSETUNE to 0, which was previously missing from the
> tuning table despite being included in the register mask.
> 
> All values are derived from the vendor kernel for the Samsung
> Galaxy A6 (SM-A600FN), as no public hardware documentation is
> available for the Exynos7870 USB DRD PHY. With these corrections,
> the PHY successfully negotiates high-speed (480Mbps) operation.
> 
> Fixes: 588d5d20ca8d ("phy: exynos5-usbdrd: add exynos7870 USBDRD support")
> Cc: stable@vger.kernel.org
> Tested-by: Łukasz Lebiedziński <kernel@lvkasz.us>

Drop you are the author. This is for 3rd party credits.

> Tested-by: Kaustabh Chakraborty <kauschluss@disroot.org>
> Signed-off-by: Łukasz Lebiedziński <kernel@lvkasz.us>
> ---
>  drivers/phy/samsung/phy-exynos5-usbdrd.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/phy/samsung/phy-exynos5-usbdrd.c b/drivers/phy/samsung/phy-exynos5-usbdrd.c
> index 5a181cb4597e..8711a3b62c8e 100644
> --- a/drivers/phy/samsung/phy-exynos5-usbdrd.c
> +++ b/drivers/phy/samsung/phy-exynos5-usbdrd.c
> @@ -1958,13 +1958,14 @@ const struct exynos5_usbdrd_phy_tuning exynos7870_tunes_utmi_postinit[] = {
>  			      PHYPARAM0_TXPREEMPAMPTUNE | PHYPARAM0_TXHSXVTUNE |
>  			      PHYPARAM0_TXFSLSTUNE | PHYPARAM0_SQRXTUNE |
>  			      PHYPARAM0_OTGTUNE | PHYPARAM0_COMPDISTUNE),
> -			     (FIELD_PREP_CONST(PHYPARAM0_TXVREFTUNE, 14) |
> +			     (FIELD_PREP_CONST(PHYPARAM0_TXVREFTUNE, 3) |
>  			      FIELD_PREP_CONST(PHYPARAM0_TXRISETUNE, 1) |
> -			      FIELD_PREP_CONST(PHYPARAM0_TXRESTUNE, 3) |
> +			      FIELD_PREP_CONST(PHYPARAM0_TXRESTUNE, 2) |
> +			      FIELD_PREP_CONST(PHYPARAM0_TXPREEMPPULSETUNE, 0) |
>  			      FIELD_PREP_CONST(PHYPARAM0_TXPREEMPAMPTUNE, 0) |
>  			      FIELD_PREP_CONST(PHYPARAM0_TXHSXVTUNE, 0) |
>  			      FIELD_PREP_CONST(PHYPARAM0_TXFSLSTUNE, 3) |
> -			      FIELD_PREP_CONST(PHYPARAM0_SQRXTUNE, 6) |
> +			      FIELD_PREP_CONST(PHYPARAM0_SQRXTUNE, 5) |
>  			      FIELD_PREP_CONST(PHYPARAM0_OTGTUNE, 2) |
>  			      FIELD_PREP_CONST(PHYPARAM0_COMPDISTUNE, 3))),

With tags corrected:

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>


Best regards,
Krzysztof