Re: [PATCH v7 2/2] mmc: sdhci-msm: Use pm ops instead of macro to restore crypto keys

[Eric Biggers <ebiggers@kernel.org>]

On Tue, Aug 18, 2026 at 01:00:21PM +0530, Ram Prakash Gupta wrote:
> 
> 
> On 8/12/2026 12:38 AM, Eric Biggers wrote:
> > On Tue, Aug 11, 2026 at 08:47:59PM +0530, Neeraj Soni wrote:
> >> From: Ram Prakash Gupta <ram.gupta@oss.qualcomm.com>
> >>
> >> Inline Crypto Engine (ICE) keys are lost after hibernation entry and this
> >> needs to be restored when hibernation exits. ICE keys are re-programmed
> >> during sdhci_msm_ice_init() but it may not cover cases where the
> >> hibernation image is already restored.
> >>
> >> Unwrap the pm ops and use directly in driver to add the call to restore
> >> Inline Crypto Engine (ICE) keys. This ensures that ICE is brought into
> >> same state as before hibernation.
> >>
> >> Also set MMC_CAP2_CRYPTO_NO_REPROG to indicate that re-programming of ICE
> >> keys is not needed during MMC runtime suspend/resume.
> >>
> >> Signed-off-by: Ram Prakash Gupta <ram.gupta@oss.qualcomm.com>
> >> Signed-off-by: Seshu Madhavi Puppala <quic_spuppala@quicinc.com>
> >> Co-developed-by: Ram Prakash Gupta <quic_rampraka@quicinc.com>
> >> Signed-off-by: Ram Prakash Gupta <quic_rampraka@quicinc.com>
> >> Co-developed-by: Sarthak Garg <quic_sartgarg@quicinc.com>
> >> Signed-off-by: Sarthak Garg <quic_sartgarg@quicinc.com>
> >> Signed-off-by: Debraj Mukhopadhyay <quic_dmukhopa@quicinc.com>
> >> Signed-off-by: Neeraj Soni <neeraj.soni@oss.qualcomm.com>
> >> ---
> >>  drivers/mmc/host/sdhci-msm.c | 32 +++++++++++++++++++++++++++++++-
> >>  1 file changed, 31 insertions(+), 1 deletion(-)
> > 
> > So with this patch, resume from hibernation will be the *only* time that
> > ICE keys are reprogrammed.  Are you absolutely sure that is enough on
> > every SoC this driver supports?  What about resume from suspend-to-RAM?
> > CQE error recovery?  What if the hibernation image fails to be created?
> > 
> > - Eric
> 
> Hi Eric,
> 
> There are two scenarios where key would be required to reprogram, first is when
> rail powering the ICE goes off or SDCC does BCR reset.
> 
> now during suspend-to-RAM, rail powering the ice wont go off, so key would not
> be required to reprogram. During CQE recovery, key would be only lost when BCR
> reset is performed but that is not happening right now, to be taken up once its
> fixed as part of recovery flow. And in case hibernation image fails to create
> then device boots from normal flow where there is no need to reprogram the keys.
> 

Okay this patch should be okay then.  Seems that the commit message
needs some work though to properly explain this.

- Eric