From 3a39049f88e4e92823bcc43fa8f148cf7dfdda67 Mon Sep 17 00:00:00 2001 From: Bjorn Andersson Date: Thu, 15 Sep 2022 13:55:59 -0700 Subject: [PATCH] soc: qcom: rpmhpd: Use highest corner until sync_state In some cases the hardware that the bootloader has left configured depends on RPMH power domains for their operation up until the point where the related Linux device driver probes and can inherit that configuration, or power down the hardware gracefully. Unfortunately as Linux probes the releavant drivers in sequence there are periods during the Linux boot flow where either the genpd refcount will reach 0, or worse where the active performance_state votes does not meet the requirements of the state that the hardware was left in. One specific example of this is during boot of e.g. SM8150/SC8180X, where the display clock controller probes, without any particular performance state needs (to access its registers). This will drop the MMCX rail to MIN_SVS, which isn't sufficient to sustain the clock rates that the later probing MDP is configured to. This results in an unrecoverable system state. Handle both these cases by keeping the RPMH power-domais that are referenced voted for highest state, until sync_state indicates that all devices referencing the RPMH power-domain driver has been probed. Signed-off-by: Bjorn Andersson Reviewed-by: Caleb Connolly Reviewed-by: Konrad Dybcio Reviewed-by: Dmitry Baryshkov [bjorn: Added print for sync_state errors] Signed-off-by: Bjorn Andersson Signed-off-by: Bjorn Andersson Link: https://lore.kernel.org/r/20220915205559.14574-1-quic_bjorande@quicinc.com --- drivers/soc/qcom/rpmhpd.c | 39 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 38 insertions(+), 1 deletion(-) diff --git a/drivers/soc/qcom/rpmhpd.c b/drivers/soc/qcom/rpmhpd.c index 319a2cf..b0c0e15 100644 --- a/drivers/soc/qcom/rpmhpd.c +++ b/drivers/soc/qcom/rpmhpd.c @@ -39,6 +39,7 @@ * @res_name: Resource name used for cmd-db lookup * @addr: Resource address as looped up using resource name from * cmd-db + * @state_synced: Indicator that sync_state has been invoked for the rpmhpd resource */ struct rpmhpd { struct device *dev; @@ -54,6 +55,7 @@ struct rpmhpd { bool enabled; const char *res_name; u32 addr; + bool state_synced; }; struct rpmhpd_desc { @@ -511,7 +513,13 @@ static int rpmhpd_aggregate_corner(struct rpmhpd *pd, unsigned int corner) unsigned int this_active_corner = 0, this_sleep_corner = 0; unsigned int peer_active_corner = 0, peer_sleep_corner = 0; - to_active_sleep(pd, corner, &this_active_corner, &this_sleep_corner); + if (pd->state_synced) { + to_active_sleep(pd, corner, &this_active_corner, &this_sleep_corner); + } else { + /* Clamp to highest corner if sync_state hasn't happened */ + this_active_corner = pd->level_count - 1; + this_sleep_corner = pd->level_count - 1; + } if (peer && peer->enabled) to_active_sleep(peer, peer->corner, &peer_active_corner, @@ -726,11 +734,40 @@ static int rpmhpd_probe(struct platform_device *pdev) return of_genpd_add_provider_onecell(pdev->dev.of_node, data); } +static void rpmhpd_sync_state(struct device *dev) +{ + const struct rpmhpd_desc *desc = of_device_get_match_data(dev); + struct rpmhpd **rpmhpds = desc->rpmhpds; + unsigned int corner; + struct rpmhpd *pd; + unsigned int i; + int ret; + + mutex_lock(&rpmhpd_lock); + for (i = 0; i < desc->num_pds; i++) { + pd = rpmhpds[i]; + if (!pd) + continue; + + pd->state_synced = true; + if (pd->enabled) + corner = max(pd->corner, pd->enable_corner); + else + corner = 0; + + ret = rpmhpd_aggregate_corner(pd, corner); + if (ret) + dev_err(dev, "failed to sync %s\n", pd->res_name); + } + mutex_unlock(&rpmhpd_lock); +} + static struct platform_driver rpmhpd_driver = { .driver = { .name = "qcom-rpmhpd", .of_match_table = rpmhpd_match_table, .suppress_bind_attrs = true, + .sync_state = rpmhpd_sync_state, }, .probe = rpmhpd_probe, }; -- 2.7.4