Hi Tomi,
Thanks for reviewing the patches!
On 26/06/24 15:55, Tomi Valkeinen wrote:
> Hi,
>
> On 22/06/2024 14:09, Aradhya Bhatia wrote:
>> Initialize the Phy during the cdns-dsi _resume(), and de-initialize it
>> during the _suspend().
>>
>> Also power-off the Phy from bridge_disable.
>>
>> Fixes: fced5a364dee ("drm/bridge: cdns: Convert to phy framework")
>> Signed-off-by: Aradhya Bhatia <a-bhat...@ti.com>
>> ---
>> drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c | 10 ++++++++--
>> 1 file changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
>> b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
>> index 5159c3f0853e..d89c32bae2b9 100644
>> --- a/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
>> +++ b/drivers/gpu/drm/bridge/cadence/cdns-dsi-core.c
>> @@ -672,6 +672,10 @@ static void cdns_dsi_bridge_disable(struct
>> drm_bridge *bridge)
>> if (dsi->platform_ops && dsi->platform_ops->disable)
>> dsi->platform_ops->disable(dsi);
>> + phy_power_off(dsi->dphy);
>> + dsi->link_initialized = false;
>> + dsi->phy_initialized = false;
>> +
>> pm_runtime_put(dsi->base.dev);
>> }
>> @@ -698,7 +702,6 @@ static void cdns_dsi_hs_init(struct cdns_dsi *dsi)
>> DPHY_CMN_PDN | DPHY_PLL_PDN,
>> dsi->regs + MCTL_DPHY_CFG0);
>> - phy_init(dsi->dphy);
>> phy_set_mode(dsi->dphy, PHY_MODE_MIPI_DPHY);
>> phy_configure(dsi->dphy, &output->phy_opts);
>> phy_power_on(dsi->dphy);
>> @@ -1120,6 +1123,8 @@ static int __maybe_unused cdns_dsi_resume(struct
>> device *dev)
>> clk_prepare_enable(dsi->dsi_p_clk);
>> clk_prepare_enable(dsi->dsi_sys_clk);
>> + phy_init(dsi->dphy);
>> +
>> return 0;
>> }
>> @@ -1127,10 +1132,11 @@ static int __maybe_unused
>> cdns_dsi_suspend(struct device *dev)
>> {
>> struct cdns_dsi *dsi = dev_get_drvdata(dev);
>> + phy_exit(dsi->dphy);
>> +
>> clk_disable_unprepare(dsi->dsi_sys_clk);
>> clk_disable_unprepare(dsi->dsi_p_clk);
>> reset_control_assert(dsi->dsi_p_rst);
>> - dsi->link_initialized = false;
>> return 0;
>> }
>>
>
> So with this patch, phy_init/exit will be called in the resume/suspend
> functions. That looks fine.
>
> But the phy_power_on/phy_power_off looks odd to me. Here you add
> phy_power_off() to cdns_dsi_bridge_disable(), which sounds fine. But
> phy_power_on() is called in cdns_dsi_hs_init(), and that is called in
> cdns_dsi_bridge_enable() (which sounds fine), but also in
> cdns_dsi_bridge_pre_enable().
>
> So doesn't that mean cdns_dsi_hs_init() call in cdns_dsi_bridge_enable()
> is extra, as it effectively does nothing (it exists right away if
> dsi->phy_initialized == true)?
That's right. When cdns_dsi_hs_init() is called from
cdns_dsi_bridge_enable(), it is simply expected to return since
phy_initialized is true.
I am not aware about the exact reasoning behind this, but this gets
addressed when I convert the _bridge_enable() to _bridge_pre_enable()
and drop the older _bridge_pre_enable() entirely.
Regards
Aradhya
