[PATCH net 1/2] net: ti: icssg-prueth: Fix firmware load sequence.

[Meghana Malladi]

On 08/11/24 19:00, Simon Horman wrote:
> On Wed, Nov 06, 2024 at 01:10:39PM +0530, Meghana Malladi wrote:
>> From: MD Danish Anwar <danishanwar at ti.com>
>>
>> Timesync related operations are ran in PRU0 cores for both ICSSG SLICE0
>> and SLICE1. Currently whenever any ICSSG interface comes up we load the
>> respective firmwares to PRU cores and whenever interface goes down, we
>> stop the respective cores. Due to this, when SLICE0 goes down while
>> SLICE1 is still active, PRU0 firmwares are unloaded and PRU0 core is
>> stopped. This results in clock jump for SLICE1 interface as the timesync
>> related operations are no longer running.
>>
>> Fix this by running both PRU0 and PRU1 firmwares as long as at least 1
>> ICSSG interface is up.
>>
>> rx_flow_id is updated before firmware is loaded. Once firmware is loaded,
>> it reads the flow_id and uses it for rx. emac_fdb_flow_id_updated() is
>> used to let firmware know that the flow_id has been updated and to use the
>> latest rx_flow_id.
>>
>> Fixes: c1e0230eeaab ("net: ti: icss-iep: Add IEP driver")
>> Signed-off-by: MD Danish Anwar <danishanwar at ti.com>
>> Signed-off-by: Meghana Malladi <m-malladi at ti.com>
> 
> ...
> 
>> diff --git a/drivers/net/ethernet/ti/icssg/icssg_config.h b/drivers/net/ethernet/ti/icssg/icssg_config.h
> 
> ...
> 
>> diff --git a/drivers/net/ethernet/ti/icssg/icssg_prueth.c b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
>> index 0556910938fa..9df67539285b 100644
>> --- a/drivers/net/ethernet/ti/icssg/icssg_prueth.c
>> +++ b/drivers/net/ethernet/ti/icssg/icssg_prueth.c
>> @@ -534,6 +534,7 @@ static int emac_ndo_open(struct net_device *ndev)
>>   {
>>   	struct prueth_emac *emac = netdev_priv(ndev);
>>   	int ret, i, num_data_chn = emac->tx_ch_num;
>> +	struct icssg_flow_cfg __iomem *flow_cfg;
>>   	struct prueth *prueth = emac->prueth;
>>   	int slice = prueth_emac_slice(emac);
>>   	struct device *dev = prueth->dev;
>> @@ -549,8 +550,12 @@ static int emac_ndo_open(struct net_device *ndev)
>>   	/* set h/w MAC as user might have re-configured */
>>   	ether_addr_copy(emac->mac_addr, ndev->dev_addr);
>>   
>> +	if (!prueth->emacs_initialized) {
>> +		icssg_class_default(prueth->miig_rt, ICSS_SLICE0, 0, false);
>> +		icssg_class_default(prueth->miig_rt, ICSS_SLICE1, 0, false);
>> +	}
>> +
>>   	icssg_class_set_mac_addr(prueth->miig_rt, slice, emac->mac_addr);
>> -	icssg_class_default(prueth->miig_rt, slice, 0, false);
>>   	icssg_ft1_set_mac_addr(prueth->miig_rt, slice, emac->mac_addr);
>>   
>>   	/* Notify the stack of the actual queue counts. */
>> @@ -588,10 +593,31 @@ static int emac_ndo_open(struct net_device *ndev)
>>   		goto cleanup_napi;
>>   	}
>>   
>> -	/* reset and start PRU firmware */
>> -	ret = prueth_emac_start(prueth, emac);
>> -	if (ret)
>> -		goto free_rx_irq;
>> +	if (!prueth->emacs_initialized) {
>> +		if (prueth->emac[ICSS_SLICE0]) {
>> +			ret = prueth_emac_start(prueth, prueth->emac[ICSS_SLICE0]);
> 
> I wonder if it is worth simplifying this by having prueth_emac_start()
> check if it's 2nd parameter is NULL. Likewise for prueth_emac_stop().
> 
Yes right, I will update this.
>> +			if (ret) {
>> +				netdev_err(ndev, "unable to start fw for slice %d", ICSS_SLICE0);
>> +				goto free_rx_irq;
>> +			}
>> +		}
>> +		if (prueth->emac[ICSS_SLICE1]) {
>> +			ret = prueth_emac_start(prueth, prueth->emac[ICSS_SLICE1]);
>> +			if (ret) {
>> +				netdev_err(ndev, "unable to start fw for slice %d", ICSS_SLICE1);
>> +				goto halt_slice0_prus;
>> +			}
>> +		}
>> +	}
>> +
>> +	flow_cfg = emac->dram.va + ICSSG_CONFIG_OFFSET + PSI_L_REGULAR_FLOW_ID_BASE_OFFSET;
>> +	writew(emac->rx_flow_id_base, &flow_cfg->rx_base_flow);
>> +	ret = emac_fdb_flow_id_updated(emac);
>> +
>> +	if (ret) {
>> +		netdev_err(ndev, "Failed to update Rx Flow ID %d", ret);
>> +		goto stop;
> 
> Branching to stop may result in calls to prueth_emac_stop() which does not
> seem symmetrical with the condition on prueth->emacs_initialized for calls
> to prueth_emac_start() above.
> 
> If so, is this intended?
> 
Yes this is intended. This change is made to run all the cores during 
init and in case of any failure, stop all the cores. And even if one 
interface is up, all the cores should run.
>> +	}
>>   
>>   	icssg_mii_update_mtu(prueth->mii_rt, slice, ndev->max_mtu);
>>   
> 
> ...