On 6/12/25 12:09, Varadarajan Narayanan wrote:
On Wed, Jun 11, 2025 at 01:55:32PM +0200, Casey Connolly wrote:
Hi Varadarajan,
On 5/7/25 09:07, Varadarajan Narayanan wrote:
Using the 'reboot edl' command in Linux, the platform can reboot to the
Emergency Download mode. Implement the same for U-Boot.
v3: * Introduce a sysreset op that will pass down the 'reset' command
arguments to registered handlers
* Handle 'reset to edl' alone in qcom-psci driver
v2: * Rebased to recent sources
* Dropped the first patch as it is not applicable anymore
* Bind the new driver from psci driver
Sorry for the late reply.
This really needs some associated documentation, at least adding the edl arg
to doc/usage/cmd/reset.rst and the help output in cmd/boot.c should describe
the edl arg if CONFIG_SYSRESET_QCOM_PSCI is enabled.
ok.
it also doesn't build?
../drivers/sysreset/sysreset-uclass.c: In function 'sysreset_walk_arg':
../drivers/sysreset/sysreset-uclass.c:93:63: error: passing argument 3 of
'sysreset_request_arg' from incompatible pointer type
[-Wincompatible-pointer-types]
93 | ret = sysreset_request_arg(dev, argc, argv);
| ^~~~
| |
| char * const*
../drivers/sysreset/sysreset-uclass.c:35:69: note: expected 'const char **'
but argument is of type 'char * const*'
35 | int sysreset_request_arg(struct udevice *dev, int argc, const char
*argv[])
ok.
ignoring that for a sec, I'm a bit worried still about how this behaves on
boards that don't implement this psci call, on sdm845 for example we just
hang.
I think psci_system_reset2() should be adjusted to time out (though I can't
imagine a psci implementation that would return execution to el1 during the
reset, so maybe the timeout isn't even needed?) and return an error if the
reset didn't happen.
Would checking if the system-reset2 function is implemented in PSCI and
handling appropriately similar to [1] be ok? Please let me know.
Yeah that looks good.
Then qcom_psci_sysreset_request_arg() should print some useful error message
("reset2 not supported on this platform, reset to edl failed") and bubble up
the error code to abort the reset entirely.
If the function is not implemented will print a message and bubble up
-EPROTONOSUPPORT.
Makes sense. Thanks!>
1 -
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/firmware/psci/psci.c#n554
Thanks
Varada
--
Casey (she/they)
