Re: [PATCH 3/4] phy: cadence-torrent: Do not configure SERDES if it's already configured

From: Kishon Vijay Abraham I
Date: Tue Mar 30 2021 - 05:58:24 EST


Hi Swapnil,

On 18/03/21 3:25 pm, Swapnil Kashinath Jakhade wrote:
>
>
>> -----Original Message-----
>> From: Kishon Vijay Abraham I <kishon@xxxxxx>
>> Sent: Wednesday, March 10, 2021 9:25 PM
>> To: Kishon Vijay Abraham I <kishon@xxxxxx>; Vinod Koul
>> <vkoul@xxxxxxxxxx>; Rob Herring <robh+dt@xxxxxxxxxx>; Philipp Zabel
>> <p.zabel@xxxxxxxxxxxxxx>; Swapnil Kashinath Jakhade
>> <sjakhade@xxxxxxxxxxx>
>> Cc: linux-kernel@xxxxxxxxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; Lokesh Vutla
>> <lokeshvutla@xxxxxx>; linux-phy@xxxxxxxxxxxxxxxxxxx
>> Subject: [PATCH 3/4] phy: cadence-torrent: Do not configure SERDES if it's
>> already configured
>>
>> EXTERNAL MAIL
>>
>>
>> Do not configure torrent SERDES if it's already configured.
>>
>> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
>> ---
>> drivers/phy/cadence/phy-cadence-torrent.c | 32 ++++++++++++++++-------
>> 1 file changed, 22 insertions(+), 10 deletions(-)
>>
>> diff --git a/drivers/phy/cadence/phy-cadence-torrent.c
>> b/drivers/phy/cadence/phy-cadence-torrent.c
>> index ab51c4bf7b30..5ee1657f5a1c 100644
>> --- a/drivers/phy/cadence/phy-cadence-torrent.c
>> +++ b/drivers/phy/cadence/phy-cadence-torrent.c
>> @@ -371,6 +371,10 @@ static const struct phy_ops cdns_torrent_phy_ops =
>> {
>> .owner = THIS_MODULE,
>> };
>>
>> +static const struct phy_ops noop_ops = {
>> + .owner = THIS_MODULE,
>> +};
>> +
>> struct cdns_reg_pairs {
>> u32 val;
>> u32 off;
>> @@ -2306,6 +2310,7 @@ static int cdns_torrent_phy_probe(struct
>> platform_device *pdev)
>> struct device_node *child;
>> int ret, subnodes, node = 0, i;
>> u32 total_num_lanes = 0;
>> + int already_configured;
>> u8 init_dp_regmap = 0;
>> u32 phy_type;
>>
>> @@ -2344,16 +2349,20 @@ static int cdns_torrent_phy_probe(struct
>> platform_device *pdev)
>> if (ret)
>> return ret;
>>
>> - ret = cdns_torrent_reset(cdns_phy);
>> - if (ret)
>> - goto clk_cleanup;
>> + regmap_field_read(cdns_phy->phy_pma_cmn_ctrl_1,
>> &already_configured);
>>
>> - ret = cdns_torrent_clk(cdns_phy);
>> - if (ret)
>> - goto clk_cleanup;
>> + if (!already_configured) {
>> + ret = cdns_torrent_reset(cdns_phy);
>> + if (ret)
>> + goto clk_cleanup;
>> +
>> + ret = cdns_torrent_clk(cdns_phy);
>> + if (ret)
>> + goto clk_cleanup;
>>
> Should if (!already_configured) be checked while calling clk_disable_unprepare()?

Both clk_unprepare() and clk_disable() checks for passed clk for ERR or
NULL. So don't think it's necessary to have !already_configured check.
> Otherwise,
> Reviewed-by: Swapnil Jakhade <sjakhade@xxxxxxxxxxx>

Thanks
Kishon

>
> Thanks & regards,
> Swapnil
>
>> - /* Enable APB */
>> - reset_control_deassert(cdns_phy->apb_rst);
>> + /* Enable APB */
>> + reset_control_deassert(cdns_phy->apb_rst);
>> + }
>>
>> for_each_available_child_of_node(dev->of_node, child) {
>> struct phy *gphy;
>> @@ -2423,7 +2432,10 @@ static int cdns_torrent_phy_probe(struct
>> platform_device *pdev)
>> of_property_read_u32(child, "cdns,ssc-mode",
>> &cdns_phy->phys[node].ssc_mode);
>>
>> - gphy = devm_phy_create(dev, child,
>> &cdns_torrent_phy_ops);
>> + if (!already_configured)
>> + gphy = devm_phy_create(dev, child,
>> &cdns_torrent_phy_ops);
>> + else
>> + gphy = devm_phy_create(dev, child, &noop_ops);
>> if (IS_ERR(gphy)) {
>> ret = PTR_ERR(gphy);
>> goto put_child;
>> @@ -2507,7 +2519,7 @@ static int cdns_torrent_phy_probe(struct
>> platform_device *pdev)
>> goto put_lnk_rst;
>> }
>>
>> - if (cdns_phy->nsubnodes > 1) {
>> + if (cdns_phy->nsubnodes > 1 && !already_configured) {
>> ret = cdns_torrent_phy_configure_multilink(cdns_phy);
>> if (ret)
>> goto put_lnk_rst;
>> --
>> 2.17.1
>