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linux-next/drivers/pnp/driver.c
Heiner Kallweit e0f03e87fc PNP: respect PNP_DRIVER_RES_DO_NOT_CHANGE when detaching
I have a device (Nuvoton 6779D Super-IO IR RC with nuvoton-cir driver)
which works after initial boot but not any longer if I unload and
re-load the driver module.

Digging into the issue I found that unloading the driver calls
pnp_disable_dev although the driver has flag PNP_DRIVER_RES_DO_NOT_CHANGE
set. IMHO this is not right.

Let's have a look at the call chain when probing a device:
pnp_device_probe
1. attaches the device
2. if it's not active and PNP_DRIVER_RES_DO_NOT_CHANGE is not set
   it gets activated
3. probes driver

I think pnp_device_remove should do it in reverse order and also
respect PNP_DRIVER_RES_DO_NOT_CHANGE. Therefore:
1. call drivers remove callback
2. if device is active and PNP_DRIVER_RES_DO_NOT_CHANGE is not set
   disable it
3. detach device

The change works for me and sounds logical to me.
However I don't know the pnp driver in detail so I might be wrong.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-04 22:12:42 +01:00

317 lines
6.4 KiB
C

/*
* driver.c - device id matching, driver model, etc.
*
* Copyright 2002 Adam Belay <ambx1@neo.rr.com>
*/
#include <linux/string.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/ctype.h>
#include <linux/slab.h>
#include <linux/pnp.h>
#include "base.h"
static int compare_func(const char *ida, const char *idb)
{
int i;
/* we only need to compare the last 4 chars */
for (i = 3; i < 7; i++) {
if (ida[i] != 'X' &&
idb[i] != 'X' && toupper(ida[i]) != toupper(idb[i]))
return 0;
}
return 1;
}
int compare_pnp_id(struct pnp_id *pos, const char *id)
{
if (!pos || !id || (strlen(id) != 7))
return 0;
if (memcmp(id, "ANYDEVS", 7) == 0)
return 1;
while (pos) {
if (memcmp(pos->id, id, 3) == 0)
if (compare_func(pos->id, id) == 1)
return 1;
pos = pos->next;
}
return 0;
}
static const struct pnp_device_id *match_device(struct pnp_driver *drv,
struct pnp_dev *dev)
{
const struct pnp_device_id *drv_id = drv->id_table;
if (!drv_id)
return NULL;
while (*drv_id->id) {
if (compare_pnp_id(dev->id, drv_id->id))
return drv_id;
drv_id++;
}
return NULL;
}
int pnp_device_attach(struct pnp_dev *pnp_dev)
{
mutex_lock(&pnp_lock);
if (pnp_dev->status != PNP_READY) {
mutex_unlock(&pnp_lock);
return -EBUSY;
}
pnp_dev->status = PNP_ATTACHED;
mutex_unlock(&pnp_lock);
return 0;
}
void pnp_device_detach(struct pnp_dev *pnp_dev)
{
mutex_lock(&pnp_lock);
if (pnp_dev->status == PNP_ATTACHED)
pnp_dev->status = PNP_READY;
mutex_unlock(&pnp_lock);
}
static int pnp_device_probe(struct device *dev)
{
int error;
struct pnp_driver *pnp_drv;
struct pnp_dev *pnp_dev;
const struct pnp_device_id *dev_id = NULL;
pnp_dev = to_pnp_dev(dev);
pnp_drv = to_pnp_driver(dev->driver);
error = pnp_device_attach(pnp_dev);
if (error < 0)
return error;
if (pnp_dev->active == 0) {
if (!(pnp_drv->flags & PNP_DRIVER_RES_DO_NOT_CHANGE)) {
error = pnp_activate_dev(pnp_dev);
if (error < 0)
return error;
}
} else if ((pnp_drv->flags & PNP_DRIVER_RES_DISABLE)
== PNP_DRIVER_RES_DISABLE) {
error = pnp_disable_dev(pnp_dev);
if (error < 0)
return error;
}
error = 0;
if (pnp_drv->probe) {
dev_id = match_device(pnp_drv, pnp_dev);
if (dev_id != NULL)
error = pnp_drv->probe(pnp_dev, dev_id);
}
if (error >= 0) {
pnp_dev->driver = pnp_drv;
error = 0;
} else
goto fail;
return error;
fail:
pnp_device_detach(pnp_dev);
return error;
}
static int pnp_device_remove(struct device *dev)
{
struct pnp_dev *pnp_dev = to_pnp_dev(dev);
struct pnp_driver *drv = pnp_dev->driver;
if (drv) {
if (drv->remove)
drv->remove(pnp_dev);
pnp_dev->driver = NULL;
}
if (pnp_dev->active &&
(!drv || !(drv->flags & PNP_DRIVER_RES_DO_NOT_CHANGE)))
pnp_disable_dev(pnp_dev);
pnp_device_detach(pnp_dev);
return 0;
}
static void pnp_device_shutdown(struct device *dev)
{
struct pnp_dev *pnp_dev = to_pnp_dev(dev);
struct pnp_driver *drv = pnp_dev->driver;
if (drv && drv->shutdown)
drv->shutdown(pnp_dev);
}
static int pnp_bus_match(struct device *dev, struct device_driver *drv)
{
struct pnp_dev *pnp_dev = to_pnp_dev(dev);
struct pnp_driver *pnp_drv = to_pnp_driver(drv);
if (match_device(pnp_drv, pnp_dev) == NULL)
return 0;
return 1;
}
static int __pnp_bus_suspend(struct device *dev, pm_message_t state)
{
struct pnp_dev *pnp_dev = to_pnp_dev(dev);
struct pnp_driver *pnp_drv = pnp_dev->driver;
int error;
if (!pnp_drv)
return 0;
if (pnp_drv->driver.pm && pnp_drv->driver.pm->suspend) {
error = pnp_drv->driver.pm->suspend(dev);
suspend_report_result(pnp_drv->driver.pm->suspend, error);
if (error)
return error;
}
if (pnp_drv->suspend) {
error = pnp_drv->suspend(pnp_dev, state);
if (error)
return error;
}
if (pnp_can_disable(pnp_dev)) {
error = pnp_stop_dev(pnp_dev);
if (error)
return error;
}
if (pnp_can_suspend(pnp_dev))
pnp_dev->protocol->suspend(pnp_dev, state);
return 0;
}
static int pnp_bus_suspend(struct device *dev)
{
return __pnp_bus_suspend(dev, PMSG_SUSPEND);
}
static int pnp_bus_freeze(struct device *dev)
{
return __pnp_bus_suspend(dev, PMSG_FREEZE);
}
static int pnp_bus_poweroff(struct device *dev)
{
return __pnp_bus_suspend(dev, PMSG_HIBERNATE);
}
static int pnp_bus_resume(struct device *dev)
{
struct pnp_dev *pnp_dev = to_pnp_dev(dev);
struct pnp_driver *pnp_drv = pnp_dev->driver;
int error;
if (!pnp_drv)
return 0;
if (pnp_dev->protocol->resume) {
error = pnp_dev->protocol->resume(pnp_dev);
if (error)
return error;
}
if (pnp_can_write(pnp_dev)) {
error = pnp_start_dev(pnp_dev);
if (error)
return error;
}
if (pnp_drv->driver.pm && pnp_drv->driver.pm->resume) {
error = pnp_drv->driver.pm->resume(dev);
if (error)
return error;
}
if (pnp_drv->resume) {
error = pnp_drv->resume(pnp_dev);
if (error)
return error;
}
return 0;
}
static const struct dev_pm_ops pnp_bus_dev_pm_ops = {
/* Suspend callbacks */
.suspend = pnp_bus_suspend,
.resume = pnp_bus_resume,
/* Hibernate callbacks */
.freeze = pnp_bus_freeze,
.thaw = pnp_bus_resume,
.poweroff = pnp_bus_poweroff,
.restore = pnp_bus_resume,
};
struct bus_type pnp_bus_type = {
.name = "pnp",
.match = pnp_bus_match,
.probe = pnp_device_probe,
.remove = pnp_device_remove,
.shutdown = pnp_device_shutdown,
.pm = &pnp_bus_dev_pm_ops,
.dev_groups = pnp_dev_groups,
};
int pnp_register_driver(struct pnp_driver *drv)
{
drv->driver.name = drv->name;
drv->driver.bus = &pnp_bus_type;
return driver_register(&drv->driver);
}
void pnp_unregister_driver(struct pnp_driver *drv)
{
driver_unregister(&drv->driver);
}
/**
* pnp_add_id - adds an EISA id to the specified device
* @dev: pointer to the desired device
* @id: pointer to an EISA id string
*/
struct pnp_id *pnp_add_id(struct pnp_dev *dev, const char *id)
{
struct pnp_id *dev_id, *ptr;
dev_id = kzalloc(sizeof(struct pnp_id), GFP_KERNEL);
if (!dev_id)
return NULL;
dev_id->id[0] = id[0];
dev_id->id[1] = id[1];
dev_id->id[2] = id[2];
dev_id->id[3] = tolower(id[3]);
dev_id->id[4] = tolower(id[4]);
dev_id->id[5] = tolower(id[5]);
dev_id->id[6] = tolower(id[6]);
dev_id->id[7] = '\0';
dev_id->next = NULL;
ptr = dev->id;
while (ptr && ptr->next)
ptr = ptr->next;
if (ptr)
ptr->next = dev_id;
else
dev->id = dev_id;
return dev_id;
}
EXPORT_SYMBOL(pnp_register_driver);
EXPORT_SYMBOL(pnp_unregister_driver);
EXPORT_SYMBOL(pnp_device_attach);
EXPORT_SYMBOL(pnp_device_detach);