Files
u-boot-krane/drivers/sysreset/sysreset-uclass.c
T
Quentin SchulzandTom Rini c480bbd92b drivers: sysreset: revert support for args in request
This reverts:
- commit e49c84f7bb ("doc: usage: cmd: reset: specify when the -edl
  option is available")
- commit 1076feb8a3 ("cmd: boot: fix edl being shown when not
  supported")
- commit 63c806ba0e ("qcom_defconfig: enable psci based sysreset")
- commit ef06c5d76f ("cmd: boot: Add '-edl' option to reset command
  documentation")
- commit 32825eaddc ("sysreset: Implement PSCI based reset to EDL mode
  for QCOM SoCs")
- commit fcb48b8981 ("drivers: sysreset: Add sysreset op that can take
  arguments")

There was a conflict reverting commit 63c806ba0e ("qcom_defconfig:
enable psci based sysreset") due to commit 02ef1859b4 ("configs:
Resync with savedefconfig"), but the conflict resolution was trivial.

The args support for the sysreset uclass contains a logic bug. The first
sysreset device implementing the request_arg callback will consume the
args, not support the specified arg and thus return -EPROTONOSUPPORT
which will stop the iteration over all sysreset devices.

This is an issue if one has multiple sysreset devices and each with
support for different (valid) args. If a sysreset device implements a
-dummy argument and another -foo and a user calls reset -dummy from the
U-Boot CLI, it'll depend on which sysreset device will be attempted
first. If it is the one implementing -foo, it'll return it doesn't
support the argument with -EPROTONOSUPPORT in which case the device
implementing -dummy will never be attempted and instead we'll do a cold
reset which is very likely not what's expected from the user.

Casey suggested[1] we revert this and start from scratch again with a
different implementation instead.

[1] https://lore.kernel.org/u-boot/77ff0f56-5c3b-42e7-bdd1-bf90296da900@linaro.org/

Acked-by: Casey Connolly <casey.connolly@linaro.org>
Signed-off-by: Quentin Schulz <quentin.schulz@cherry.de>
2026-07-03 13:45:58 -06:00

163 lines
2.9 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2015 Google, Inc
* Written by Simon Glass <sjg@chromium.org>
*/
#define LOG_CATEGORY UCLASS_SYSRESET
#include <command.h>
#include <cpu_func.h>
#include <dm.h>
#include <errno.h>
#include <hang.h>
#include <log.h>
#include <regmap.h>
#include <spl.h>
#include <sysreset.h>
#include <dm/device-internal.h>
#include <dm/lists.h>
#include <dm/root.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <asm/global_data.h>
int sysreset_request(struct udevice *dev, enum sysreset_t type)
{
struct sysreset_ops *ops = sysreset_get_ops(dev);
if (!ops->request)
return -ENOSYS;
return ops->request(dev, type);
}
int sysreset_get_status(struct udevice *dev, char *buf, int size)
{
struct sysreset_ops *ops = sysreset_get_ops(dev);
if (!ops->get_status)
return -ENOSYS;
return ops->get_status(dev, buf, size);
}
int sysreset_get_last(struct udevice *dev)
{
struct sysreset_ops *ops = sysreset_get_ops(dev);
if (!ops->get_last)
return -ENOSYS;
return ops->get_last(dev);
}
int sysreset_walk(enum sysreset_t type)
{
struct udevice *dev;
int ret = -ENOSYS;
while (ret != -EINPROGRESS && type < SYSRESET_COUNT) {
for (uclass_first_device(UCLASS_SYSRESET, &dev);
dev;
uclass_next_device(&dev)) {
ret = sysreset_request(dev, type);
if (ret == -EINPROGRESS)
break;
}
type++;
}
return ret;
}
int sysreset_get_last_walk(void)
{
struct udevice *dev;
int value = -ENOENT;
for (uclass_first_device(UCLASS_SYSRESET, &dev);
dev;
uclass_next_device(&dev)) {
int ret;
ret = sysreset_get_last(dev);
if (ret >= 0) {
value = ret;
break;
}
}
return value;
}
void sysreset_walk_halt(enum sysreset_t type)
{
int ret;
ret = sysreset_walk(type);
/* Wait for the reset to take effect */
if (ret == -EINPROGRESS)
mdelay(100);
/* Still no reset? Give up */
if (xpl_phase() <= PHASE_SPL)
log_err("no sysreset\n");
else
log_err("System reset not supported on this platform\n");
hang();
}
/**
* reset_cpu() - calls sysreset_walk(SYSRESET_WARM)
*/
void reset_cpu(void)
{
sysreset_walk_halt(SYSRESET_WARM);
}
#if IS_ENABLED(CONFIG_SYSRESET_CMD_RESET)
int do_reset(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
enum sysreset_t reset_type = SYSRESET_COLD;
if (argc > 2)
return CMD_RET_USAGE;
if (argc == 2 && argv[1][0] == '-' && argv[1][1] == 'w') {
reset_type = SYSRESET_WARM;
}
printf("resetting ...\n");
mdelay(100);
sysreset_walk_halt(reset_type);
return 0;
}
#endif
#if IS_ENABLED(CONFIG_SYSRESET_CMD_POWEROFF)
int do_poweroff(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
{
int ret;
puts("poweroff ...\n");
mdelay(100);
ret = sysreset_walk(SYSRESET_POWER_OFF);
if (ret == -EINPROGRESS)
mdelay(1000);
/*NOTREACHED when power off*/
return CMD_RET_FAILURE;
}
#endif
UCLASS_DRIVER(sysreset) = {
.id = UCLASS_SYSRESET,
.name = "sysreset",
};