RE: [PATCH net] ice: fix missing SMA pin initialization in DPLL subsystem

Kubalewski, Arkadiusz
2026-02-26T13:48:48Z

>From: Petr Oros <poros@redhat.com>
>Sent: Friday, February 13, 2026 3:17 PM
>
>The DPLL SMA/U.FL pin redesign introduced ice_dpll_sw_pin_frequency_get()
>which gates frequency reporting on the pin's active flag. This flag is
>determined by ice_dpll_sw_pins_update() from the PCA9575 GPIO expander
>state. Before the redesign, SMA pins were exposed as direct HW
>input/output pins and ice_dpll_frequency_get() returned the CGU
>frequency unconditionally — the PCA9575 state was never consulted.
>
>The PCA9575 powers on with all outputs high, setting ICE_SMA1_DIR_EN,
>ICE_SMA1_TX_EN, ICE_SMA2_DIR_EN and ICE_SMA2_TX_EN. Nothing in the
>driver writes the register during initialization, so
>ice_dpll_sw_pins_update() sees all pins as inactive and
>ice_dpll_sw_pin_frequency_get() permanently returns 0 Hz for every
>SW pin.
>
>Fix this by writing a default SMA configuration in
>ice_dpll_init_info_sw_pins(): clear all SMA bits, then set SMA1 and
>SMA2 as active inputs (DIR_EN=0) with U.FL1 output and U.FL2 input
>disabled. Each SMA/U.FL pair shares a physical signal path so only
>one pin per pair can be active at a time. U.FL pins still report
>frequency 0 after this fix: U.FL1 (output-only) is disabled by
>ICE_SMA1_TX_EN which keeps the TX output buffer off, and U.FL2
>(input-only) is disabled by ICE_SMA2_UFL2_RX_DIS. They can be
>activated by changing the corresponding SMA pin direction via dpll
>netlink.
>
>Fixes: 2dd5d03c77e2 ("ice: redesign dpll sma/u.fl pins control")
>Signed-off-by: Petr Oros <poros@redhat.com>

Petr, many thanks for your patch!
LGTM.
Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>

>---
> drivers/net/ethernet/intel/ice/ice_dpll.c | 17 +++++++++++++++++
> 1 file changed, 17 insertions(+)
>
>diff --git a/drivers/net/ethernet/intel/ice/ice_dpll.c
>b/drivers/net/ethernet/intel/ice/ice_dpll.c
>index 53b54e395a2ed8..c2ad39bfe177db 100644
>--- a/drivers/net/ethernet/intel/ice/ice_dpll.c
>+++ b/drivers/net/ethernet/intel/ice/ice_dpll.c
>@@ -3545,6 +3545,7 @@ static int ice_dpll_init_info_sw_pins(struct ice_pf
>*pf)
> struct ice_dpll_pin *pin;
> u32 phase_adj_max, caps;
> int i, ret;
>+ u8 data;
>
> if (pf->hw.device_id == ICE_DEV_ID_E810C_QSFP)
> input_idx_offset = ICE_E810_RCLK_PINS_NUM;
>@@ -3604,6 +3605,22 @@ static int ice_dpll_init_info_sw_pins(struct ice_pf
>*pf)
> }
> ice_dpll_phase_range_set(&pin->prop.phase_range,
>phase_adj_max);
> }
>+
>+ /* Initialize the SMA control register to a known-good default
>state.
>+ * Without this write the PCA9575 GPIO expander retains its power-on
>+ * default (all outputs high) which makes all SW pins appear
>inactive.
>+ * Set SMA1 and SMA2 as active inputs, disable U.FL1 output and
>+ * U.FL2 input.
>+ */
>+ ret = ice_read_sma_ctrl(&pf->hw, &data);
>+ if (ret)
>+ return ret;
>+ data &= ~ICE_ALL_SMA_MASK;
>+ data |= ICE_SMA1_TX_EN | ICE_SMA2_TX_EN | ICE_SMA2_UFL2_RX_DIS;
>+ ret = ice_write_sma_ctrl(&pf->hw, data);
>+ if (ret)
>+ return ret;
>+
> ret = ice_dpll_pin_state_update(pf, pin, ICE_DPLL_PIN_TYPE_SOFTWARE,
> NULL);
> if (ret)
>--
>2.52.0