[PATCH net-next v2 1/2] dpll: zl3073x: update all DPLL channels on ref_sync_set
From: Ivan Vecera <ivecera@redhat.com>
Date: 2026-08-03 12:03:01
Also in:
lkml
Subsystem:
dpll subsystem, microchip zl3073x driver, the rest · Maintainers:
Vadim Fedorenko, Arkadiusz Kubalewski, Jiri Pirko, Ivan Vecera, Min Li, Linus Torvalds
zl3073x_dpll_input_pin_ref_sync_set() excludes the sync source from automatic reference selection by setting its priority to NONE, but currently only does this on the single DPLL channel whose pin_priv was passed to the callback. Since input pins are registered with every DPLL channel, the priority update must cover all channels to prevent the sync source from remaining a selectable candidate on the other channels. This is a preparation for the following patch which changes the DPLL core to invoke pin-level set callbacks only through the pin owner's reference instead of iterating over all registered DPLL devices. Replace the single-channel priority write with a list_for_each_entry() loop over all DPLL channels. Each channel's lock is acquired individually for its read-modify-write sequence. The guard(mutex) is replaced with explicit mutex_lock/mutex_unlock to allow releasing the owner's lock before iterating, avoiding nested locking of the same mutex class. Signed-off-by: Ivan Vecera <ivecera@redhat.com> --- drivers/dpll/zl3073x/dpll.c | 46 +++++++++++++++++++++++++++---------- 1 file changed, 34 insertions(+), 12 deletions(-)
diff --git a/drivers/dpll/zl3073x/dpll.c b/drivers/dpll/zl3073x/dpll.c
index 0488ae6ac486c8..1ea924a9b986b2 100644
--- a/drivers/dpll/zl3073x/dpll.c
+++ b/drivers/dpll/zl3073x/dpll.c@@ -265,7 +265,7 @@ zl3073x_dpll_input_pin_ref_sync_set(const struct dpll_pin *dpll_pin, struct zl3073x_ref ref; int rc; - guard(mutex)(&zldpll->lock); + mutex_lock(&zldpll->lock); ref_id = zl3073x_input_pin_ref_get(pin->id); sync_ref_id = zl3073x_input_pin_ref_get(sync_pin->id);
@@ -285,17 +285,20 @@ zl3073x_dpll_input_pin_ref_sync_set(const struct dpll_pin *dpll_pin, if (sync_freq > 8000) { NL_SET_ERR_MSG(extack, "sync frequency must be 8 kHz or less"); - return -EINVAL; + rc = -EINVAL; + goto unlock; } if (ref_freq < 1000) { NL_SET_ERR_MSG(extack, "clock frequency must be 1 kHz or more"); - return -EINVAL; + rc = -EINVAL; + goto unlock; } if (ref_freq <= sync_freq) { NL_SET_ERR_MSG(extack, "clock frequency must be higher than sync frequency"); - return -EINVAL; + rc = -EINVAL; + goto unlock; } zl3073x_ref_sync_pair_set(&ref, sync_ref_id);
@@ -308,20 +311,39 @@ zl3073x_dpll_input_pin_ref_sync_set(const struct dpll_pin *dpll_pin, rc = zl3073x_ref_state_set(zldev, ref_id, &ref); if (rc) - return rc; + goto unlock; - /* Exclude sync source from automatic reference selection by setting - * its priority to NONE. On disconnect the priority is left as NONE - * and the user must explicitly make the pin selectable again. + /* All code paths accessing per-channel reference priorities are + * serialized by the subsystem dpll_lock, so it is safe to release + * our lock here before iterating over the other channels. + */ + mutex_unlock(&zldpll->lock); + + /* The datasheet recommends excluding the sync source from automatic + * reference selection by setting its priority to NONE on all DPLL + * channels. This is advisory - the ref sync pair is already + * configured, so a failure here is not fatal. On disconnect the + * priority is left as NONE and the user must explicitly make the + * pin selectable again. */ if (state == DPLL_PIN_STATE_CONNECTED) { - chan = *zl3073x_chan_state_get(zldev, zldpll->id); - zl3073x_chan_ref_prio_set(&chan, sync_ref_id, - ZL_DPLL_REF_PRIO_NONE); - return zl3073x_chan_state_set(zldev, zldpll->id, &chan); + list_for_each_entry(zldpll, &zldev->dplls, list) { + mutex_lock(&zldpll->lock); + chan = *zl3073x_chan_state_get(zldev, zldpll->id); + zl3073x_chan_ref_prio_set(&chan, sync_ref_id, + ZL_DPLL_REF_PRIO_NONE); + if (zl3073x_chan_state_set(zldev, zldpll->id, &chan)) + dev_warn(zldev->dev, + "Failed to set ref prio on DPLL%u\n", + zldpll->id); + mutex_unlock(&zldpll->lock); + } } return 0; +unlock: + mutex_unlock(&zldpll->lock); + return rc; } static int
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2.54.0