Re: [PATCH v3] i2c: imx: mark I2C adapter when hardware is powered down

[Mukesh Savaliya <mukesh.savaliya@oss.qualcomm.com>]

Thanks Carlos !

On 5/21/2026 1:57 PM, Carlos Song (OSS) wrote:
> 
> 
>> -----Original Message-----
>> From: Mukesh Savaliya <mukesh.savaliya@oss.qualcomm.com>
>> Sent: Thursday, May 21, 2026 3:40 PM
>> To: Carlos Song (OSS) <carlos.song@oss.nxp.com>; o.rempel@pengutronix.de;
>> kernel@pengutronix.de; andi.shyti@kernel.org; Frank Li <frank.li@nxp.com>;
>> s.hauer@pengutronix.de; festevam@gmail.com; Carlos Song
>> <carlos.song@nxp.com>; Bough Chen <haibo.chen@nxp.com>
>> Cc: linux-i2c@vger.kernel.org; imx@lists.linux.dev;
>> linux-arm-kernel@lists.infradead.org; linux-kernel@vger.kernel.org;
>> stable@vger.kernel.org
>> Subject: Re: [PATCH v3] i2c: imx: mark I2C adapter when hardware is powered
>> down
>>
>> [You don't often get email from mukesh.savaliya@oss.qualcomm.com. Learn
>> why this is important at https://aka.ms/LearnAboutSenderIdentification ]
>>
>> Hi Carlos,
>>
>> On 5/20/2026 3:45 PM, Carlos Song (OSS) wrote:
>>> From: Carlos Song <carlos.song@nxp.com>
>>>
>>> Mark the I2C adapter as suspended during system suspend to block
>>> further transfers, and resume it on system resume. This prevents
>>> potential hangs when the hardware is powered down but clients still attempt
>> I2C transfers.
>>>
what was the reason of this hang ? I was thinking you don't have 
interrupts working when client requested transfer but adapter was 
suspended. Please correct me if wrong.

And it would be good to mention the actual problem and why/how it occurred.
>> Code changes looks fine to me but have comment on commit log.
>>
>> It seems, you are adding support of _noirq() callbacks to allow transfers during
>> suspend/resume noirq phase of PM.
>>
>> Would it make sense if you can write "Replace system PM callbacks with noirq
>> PM callbacks" OR "Allow transfers during _noirq phase of the PM ops" instead of
>> "mark I2C adapter when hardware is powered down" ?
>>
> 
> Hi,
> 
> Thank you for your comments!
> 
> But this patch is added is not for support noirq PM callback or transfer in noirq phase.
> 
Okay, may be actual problem description can help me.
> In fact, this fix is to mark the I2C adapter as suspended during system noirq suspend to block further
> transfers, and resume it on system noirq resume. This is to prohibit I2C device calling the I2C controller
> after the system noirq suspend and before noirq resume, because at this time the I2C instance is powered
> off or the clock is disabled ... So I want to keep current commit. How do you think?
completely Makes sense. Please help add how this problem occurred and 
why ? So the change/fix will be good to understand against it.
> 
> Carlos Song