Re: [PATCH] mmc: core: Kioxia 016G01 does not enter boot mode after SLEEP

[Florian Fainelli]

On 5/11/26 07:18, Ulf Hansson wrote:
> On Mon, 13 Apr 2026 at 20:06, Florian Fainelli
> <florian.fainelli@xxxxxxxxxxxx> wrote:
> > The Kioxia 016G01 eMMC device does not exit SLEEP mode when sending CMD0
> > which prevents the system from properly resuming from S3 warm boot where
> > the eMMC is necessary to pull in the boot components.
>
> Is the bug confirmed by Kioxia?

We've been going back and forth with them without much progress as far 
as a resolution goes. Since there was no progress and I would like to 
get this included in downstream kernels at some point, this was submitted.

> If not, can you explain a bit more what is actually happening during
> system resume?

Upon entering Suspend-to-DRAM, the eMMC will be put into sleep mode. 
When our systems resume, one of our hardware cores driving the eMMC (HIF 
block) in command mode will send a CMD0 command for the eMMC device to 
exit SLEEP mode. The Kioxia 016G01 device takes 10ms rather than the 
tSLEEP_EXIT value of 1ms which is advertised and so our HIF block does 
not see the Boot ACK pattern in time and does not service the read 
request from the processor that wanted to read from eMMC, we get a reset 
of the system, rather than continue booting.

When SLEEP is not enabled, the eMMC device responds within tSLEEP_EXIT 
as advertised and we don't have that problem.

So I suppose I could reformulate the commit message and give some more 
details here if you would like?
--
Florian