On 8/31/24 7:22 AM, Ajay.Kathat@xxxxxxxxxxxxx wrote:
Hi Marek,
Hi,
2. With this patch, does the ping to the station work during the suspend state?
I haven't tested this, but that's unlikely because the host is
suspended. Still, that's not really the point here, the point is that
the whole WILC gets powered off during suspend/resume without this
patch. At least on STM32MP15xx it is, maybe on the Atmel controller it
is not, but we cannot depend on that.
Indeed, you are right. It seems, the test results have dependency on the host
controller power management behavior. In my setup, the card keep the power,
when the host is suspended.
Right, currently the driver depends on the controller behavior and it
works by accident with the atmel controller. This patch fixes that and
assures this will work on other controllers too.
AFAIR, during host suspend, the firmware continues to run without passing
frames to the host unless 'wowlan' is enabled.
There is another scenario. Let's assume a host that wants to go to suspend
(power save mode) without caring about the WiFi status, i.e., it is okay to
reconnect with the AP if required (anyway, the AP may disconnect the station
based on inactivity timeout) or have to re-trigger the DHCP request again. But
with this change, the driver would block the host from entering suspend mode.
How about adding an 'if' check for host pm_caps before calling
sdio_set_host_pm_flags(func, MMC_PM_KEEP_POWER)? In that case, it will only
request when configured by the host platform.
Since this driver does not reload the firmware into the card on resume,
the card has to be kept powered on during suspend/resume cycle. The card
can NOT be powered off during suspend/resume cycle, otherwise the
firmware is lost.
Without this flag, the card may be powered off during suspend/resume
cycle. It possibly does not happen on the Atmel controller, but it does
on the STM32MP15xx ARM MMCI one.
yes, in the Atmel controller, it is not necessary to re-program the firmware
on resume.
It is if the slot gets powered off across suspend/resume . It could be
that this does not happen on the hardware you use for testing, but the
driver cannot depend on that.
[...]
I think, the wilc firmware should resume but the connection with AP may get
closed. Additional commands to scan and reconnect with AP may be required that
should work without downloading the firmware to wilc chip again.
Currently, the slot may get powered off and then there is no firmware.
Currently, driver doesn't support re-programming of the chip when the host
resumes.
Therefore, the slot MUST stay powered on across suspend/resume.
Having that support would allow both types of hosts to suspend/resume.
Added changes to download the firmware asynchronously on resume and it is
included in the attached patch. It is based on the latest 'for-next' branch. I
was not able to test it for the suspend scenario without powering the card. If
possible, could you please try this patch in your setup.
Incase, there is no improvement with the attached patch then IMO, your patch
looks safe to keep the MMC_PM_KEEP_POWER state since host resume may not work
without the card powered-on anyway.
I think the attached patch is a new feature, this patch is a fix for
existing bug. Please submit the attached patch properly, so it can get
proper review on the ML.
Thank you
