linux-kernel - Re: [PATCH v3 1/2] phy: cadence: cdns-dphy: Fix PLL lock and O_CMN

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <e19bb1d6-307c-4ed4-b353-5d2e0668f6fb@ti.com>
Date: Fri, 20 Jun 2025 20:37:00 +0530
From: Devarsh Thakkar <devarsht@...com>
To: Tomi Valkeinen <tomi.valkeinen@...asonboard.com>
CC: <sakari.ailus@...ux.intel.com>, <u.kleine-koenig@...libre.com>,
        <vigneshr@...com>, <aradhya.bhatia@...ux.dev>, <s-jain1@...com>,
        <r-donadkar@...com>, <vkoul@...nel.org>, <kishon@...nel.org>,
        <mripard@...nel.org>, <linux-phy@...ts.infradead.org>,
        <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 1/2] phy: cadence: cdns-dphy: Fix PLL lock and
 O_CMN_READY polling

Hi,

On 18/06/25 15:31, Tomi Valkeinen wrote:
> Hi,
> 
> On 02/05/2025 06:34, Devarsh Thakkar wrote:
>> PLL lockup and O_CMN_READY assertion can only happen after common state
>> machine gets enabled (by programming DPHY_CMN_SSM register), but driver was
>> polling them before the common state machine was enabled. To fix this :
>>
>> - Add new function callbacks for polling on PLL lock and O_CMN_READY
>>    assertion.
>> - As state machine and clocks get enabled in power_on callback only, move
>>    the clock related programming part from configure callback to power_on
>>    callback and poll for the PLL lockup and O_CMN_READY assertion after
>>    state machine gets enabled.
>> - The configure callback only saves the PLL configuration received from the
>>    client driver which will be applied later on in power_on callback.
>> - Add checks to ensure configure is called before power_on and state
>>    machine is in disabled state before power_on callback is called.
>> - Disable state machine in power_off so that client driver can
>>    re-configure the PLL by following up a power_off, configure, power_on
>>    sequence.
>>
>> Cc: stable@...r.kernel.org
>> Fixes: 7a343c8bf4b5 ("phy: Add Cadence D-PHY support")
>> Signed-off-by: Devarsh Thakkar <devarsht@...com>
>> ---
>> V3:
>> - Move out clock programming logic to power_on as PLL polling and enable
>>    can happen only after SSM enable
>> - Disable state machine on power off
>>
>> V2:
>> - Return error code on polling timeout
>> - Moved out calibration logic to separate patch
>>
>>   drivers/phy/cadence/cdns-dphy.c | 109 +++++++++++++++++++++++++-------
>>   1 file changed, 85 insertions(+), 24 deletions(-)
>>
>> diff --git a/drivers/phy/cadence/cdns-dphy.c b/drivers/phy/cadence/cdns-dphy.c
>> index ed87a3970f83..a94109a63788 100644
>> --- a/drivers/phy/cadence/cdns-dphy.c
>> +++ b/drivers/phy/cadence/cdns-dphy.c
>> @@ -79,6 +79,7 @@ struct cdns_dphy_cfg {
>>   	u8 pll_ipdiv;
>>   	u8 pll_opdiv;
>>   	u16 pll_fbdiv;
>> +	u64 hs_clk_rate;
> 
> This has a minor conflict with my cdns-dsi series, as I also add
> hs_clk_rate but as u32. Also, applying both serieses,
> cdns_dphy_config_from_opts() becomes odd as the hs_clk_rate will be
> assigned back and forth between opts and cfg. Can you check this?

Understood. I think after re-basing on top of your patch, I don't need 
to assign cfg->hs_clk_rate in cdns_dphy_config_from_opts since you 
already assigned it to realized clock value in 
cdns_dsi_get_dphy_pll_cfg. I can rebase on top of your series.


Regards
Devarsh