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[11/13] phy: qcom-qmp-combo: drop power-down delay config

Message ID 20221011131416.2478-12-johan+linaro@kernel.org
State Superseded
Headers show
Series phy: qcom-qmp: further prep cleanups | expand

Commit Message

Johan Hovold Oct. 11, 2022, 1:14 p.m. UTC 
The power-down delay was included in the first version of the QMP driver
as an optional delay after powering on the PHY (using
POWER_DOWN_CONTROL) and just before starting it. Later changes modified
this sequence by powering on before initialising the PHY, but the
optional delay stayed where it was (i.e. before starting the PHY).

The vendor driver does not use a delay before starting the PHY and this
is likely not needed on any platform unless there is a corresponding
delay in the vendor kernel init sequence tables (i.e. in devicetree).

Let's keep the delay for now, but drop the redundant delay period
configuration while increasing the unnecessarily low timer slack
somewhat.

Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
---
 drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 16 +---------------
 1 file changed, 1 insertion(+), 15 deletions(-)

Comments

Dmitry Baryshkov Oct. 11, 2022, 2:05 p.m. UTC | #1 
On 11/10/2022 16:14, Johan Hovold wrote:
> The power-down delay was included in the first version of the QMP driver
> as an optional delay after powering on the PHY (using
> POWER_DOWN_CONTROL) and just before starting it. Later changes modified
> this sequence by powering on before initialising the PHY, but the
> optional delay stayed where it was (i.e. before starting the PHY).
> 
> The vendor driver does not use a delay before starting the PHY and this
> is likely not needed on any platform unless there is a corresponding
> delay in the vendor kernel init sequence tables (i.e. in devicetree).
> 
> Let's keep the delay for now, but drop the redundant delay period
> configuration while increasing the unnecessarily low timer slack
> somewhat.
> 
> Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
> ---
>   drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 16 +---------------
>   1 file changed, 1 insertion(+), 15 deletions(-)

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
diff mbox series

Patch

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
index a8e09333072e..82055d3a3536 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
@@ -63,8 +63,6 @@ 
 #define CLAMP_EN				BIT(0) /* enables i/o clamp_n */
 
 #define PHY_INIT_COMPLETE_TIMEOUT		10000
-#define POWER_DOWN_DELAY_US_MIN			10
-#define POWER_DOWN_DELAY_US_MAX			11
 
 struct qmp_phy_init_tbl {
 	unsigned int offset;
@@ -860,9 +858,6 @@  struct qmp_phy_cfg {
 
 	/* true, if PHY needs delay after POWER_DOWN */
 	bool has_pwrdn_delay;
-	/* power_down delay in usec */
-	int pwrdn_delay_min;
-	int pwrdn_delay_max;
 
 	/* Offset from PCS to PCS_USB region */
 	unsigned int pcs_usb_offset;
@@ -1031,8 +1026,6 @@  static const struct qmp_phy_cfg sc7180_usb3phy_cfg = {
 	.phy_status		= PHYSTATUS,
 
 	.has_pwrdn_delay	= true,
-	.pwrdn_delay_min	= POWER_DOWN_DELAY_US_MIN,
-	.pwrdn_delay_max	= POWER_DOWN_DELAY_US_MAX,
 };
 
 static const struct qmp_phy_cfg sc7180_dpphy_cfg = {
@@ -1102,8 +1095,6 @@  static const struct qmp_phy_cfg sdm845_usb3phy_cfg = {
 	.phy_status		= PHYSTATUS,
 
 	.has_pwrdn_delay	= true,
-	.pwrdn_delay_min	= POWER_DOWN_DELAY_US_MIN,
-	.pwrdn_delay_max	= POWER_DOWN_DELAY_US_MAX,
 };
 
 static const struct qmp_phy_combo_cfg sdm845_usb3dpphy_cfg = {
@@ -1138,10 +1129,7 @@  static const struct qmp_phy_cfg sm8150_usb3phy_cfg = {
 	.pwrdn_ctrl		= SW_PWRDN,
 	.phy_status		= PHYSTATUS,
 
-
 	.has_pwrdn_delay	= true,
-	.pwrdn_delay_min	= POWER_DOWN_DELAY_US_MIN,
-	.pwrdn_delay_max	= POWER_DOWN_DELAY_US_MAX,
 };
 
 static const struct qmp_phy_cfg sc8180x_dpphy_cfg = {
@@ -1282,8 +1270,6 @@  static const struct qmp_phy_cfg sm8250_usb3phy_cfg = {
 	.phy_status		= PHYSTATUS,
 
 	.has_pwrdn_delay	= true,
-	.pwrdn_delay_min	= POWER_DOWN_DELAY_US_MIN,
-	.pwrdn_delay_max	= POWER_DOWN_DELAY_US_MAX,
 };
 
 static const struct qmp_phy_cfg sm8250_dpphy_cfg = {
@@ -2064,7 +2050,7 @@  static int qmp_combo_power_on(struct phy *phy)
 		qmp_combo_configure(pcs, cfg->pcs_tbl, cfg->pcs_tbl_num);
 
 	if (cfg->has_pwrdn_delay)
-		usleep_range(cfg->pwrdn_delay_min, cfg->pwrdn_delay_max);
+		usleep_range(10, 20);
 
 	if (cfg->type != PHY_TYPE_DP) {
 		/* Pull PHY out of reset state */