ata: ahci_st: Do not ignore errors when getting the reset controls

st_ahci_probe_resets() treats any error from devm_reset_control_get() as
"reset control not defined" and continues with a NULL reset control:

	drv_data->pwr = devm_reset_control_get(dev, "pwr-dwn");
	if (IS_ERR(drv_data->pwr)) {
		dev_info(dev, "power reset control not defined\n");
		drv_data->pwr = NULL;
	}

This also swallows -EPROBE_DEFER, which is returned when the reset
controller providing the reset has not been probed yet. probe() then
continues as if the device tree did not specify any reset, so the resets
of the SATA IP are never deasserted, and st_ahci_configure_oob() and
ahci_platform_init_host() access the MMIO of an IP which is still held in
reset and powered down, which can result in an external abort.

The resets are optional in the binding, as they are not part of its
required properties, so use devm_reset_control_get_optional(), which
returns NULL if the reset is not specified in the device tree, and
propagate all other errors.

Note that an absent reset is now indicated by a NULL reset control
instead of an error, so the "reset control not defined" messages are
dropped.

Fixes: 76884cb2f7da ("ahci: st: Add support for ST's SATA IP")
Cc: stable@vger.kernel.org
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20260915084127.692494-9-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>

0 files changed, 0 insertions, 0 deletions