Implemented HCD initialization/deinitialization functionality.
Signed-off-by: Vladimir Stankovic <[email protected]>
---
drivers/usb/host/mausb/Makefile | 1 +
drivers/usb/host/mausb/hcd.c | 120 ++++++++++++++++++++++++++++
drivers/usb/host/mausb/hcd.h | 65 +++++++++++++++
drivers/usb/host/mausb/mausb_core.c | 18 ++++-
4 files changed, 203 insertions(+), 1 deletion(-)
create mode 100644 drivers/usb/host/mausb/hcd.c
create mode 100644 drivers/usb/host/mausb/hcd.h
diff --git a/drivers/usb/host/mausb/Makefile b/drivers/usb/host/mausb/Makefile
index acc8ad3f0eff..4d655cb7fab4 100644
--- a/drivers/usb/host/mausb/Makefile
+++ b/drivers/usb/host/mausb/Makefile
@@ -9,3 +9,4 @@ obj-$(CONFIG_USB_HOST_MAUSB) += mausb_host.o
mausb_host-y := mausb_core.o
mausb_host-y += utils.o
mausb_host-y += ip_link.o
+mausb_host-y += hcd.o
diff --git a/drivers/usb/host/mausb/hcd.c b/drivers/usb/host/mausb/hcd.c
new file mode 100644
index 000000000000..3a6ef9313dcb
--- /dev/null
+++ b/drivers/usb/host/mausb/hcd.c
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 - 2020 DisplayLink (UK) Ltd.
+ */
+#include "hcd.h"
+
+#include "utils.h"
+
+static int mausb_bus_match(struct device *dev, struct device_driver *drv);
+
+static const struct file_operations mausb_fops;
+
+static unsigned int major;
+static unsigned int minor = 1;
+static dev_t devt;
+static struct device *device;
+
+struct mausb_hcd *mhcd;
+static struct class *mausb_class;
+static struct bus_type mausb_bus_type = {
+ .name = DEVICE_NAME,
+ .match = mausb_bus_match,
+};
+
+static struct device_driver mausb_driver = {
+ .name = DEVICE_NAME,
+ .bus = &mausb_bus_type,
+ .owner = THIS_MODULE,
+};
+
+static void mausb_remove(void)
+{
+ struct usb_hcd *hcd, *shared_hcd;
+
+ hcd = mhcd->hcd_hs_ctx->hcd;
+ shared_hcd = mhcd->hcd_ss_ctx->hcd;
+
+ if (shared_hcd) {
+ usb_remove_hcd(shared_hcd);
+ usb_put_hcd(shared_hcd);
+ mhcd->hcd_ss_ctx = NULL;
+ }
+
+ usb_remove_hcd(hcd);
+ usb_put_hcd(hcd);
+ mhcd->hcd_hs_ctx = NULL;
+}
+
+static int mausb_bus_match(struct device *dev, struct device_driver *drv)
+{
+ if (strncmp(dev->bus->name, drv->name, strlen(drv->name)))
+ return 0;
+ else
+ return 1;
+}
+
+int mausb_init_hcd(void)
+{
+ int retval = register_chrdev(0, DEVICE_NAME, &mausb_fops);
+
+ if (retval < 0)
+ return retval;
+
+ major = (unsigned int)retval;
+ retval = bus_register(&mausb_bus_type);
+ if (retval)
+ goto bus_register_error;
+
+ mausb_class = class_create(THIS_MODULE, CLASS_NAME);
+ if (IS_ERR(mausb_class)) {
+ retval = (int)PTR_ERR(mausb_class);
+ goto class_error;
+ }
+
+ retval = driver_register(&mausb_driver);
+ if (retval)
+ goto driver_register_error;
+
+ mhcd = kzalloc(sizeof(*mhcd), GFP_ATOMIC);
+ if (!mhcd) {
+ retval = -ENOMEM;
+ goto mausb_hcd_alloc_failed;
+ }
+
+ devt = MKDEV(major, minor);
+ device = device_create(mausb_class, NULL, devt, mhcd, DEVICE_NAME);
+ if (IS_ERR(device)) {
+ retval = (int)IS_ERR(device);
+ goto device_create_error;
+ }
+
+ device->driver = &mausb_driver;
+
+ return retval;
+device_create_error:
+ kfree(mhcd);
+ mhcd = NULL;
+mausb_hcd_alloc_failed:
+ driver_unregister(&mausb_driver);
+driver_register_error:
+ class_destroy(mausb_class);
+class_error:
+ bus_unregister(&mausb_bus_type);
+bus_register_error:
+ unregister_chrdev(major, DEVICE_NAME);
+
+ return retval;
+}
+
+void mausb_deinit_hcd(void)
+{
+ if (mhcd) {
+ mausb_remove();
+ device_destroy(mausb_class, devt);
+ driver_unregister(&mausb_driver);
+ class_destroy(mausb_class);
+ bus_unregister(&mausb_bus_type);
+ unregister_chrdev(major, DEVICE_NAME);
+ }
+}
diff --git a/drivers/usb/host/mausb/hcd.h b/drivers/usb/host/mausb/hcd.h
new file mode 100644
index 000000000000..e2374af67663
--- /dev/null
+++ b/drivers/usb/host/mausb/hcd.h
@@ -0,0 +1,65 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2019 - 2020 DisplayLink (UK) Ltd.
+ */
+#ifndef __MAUSB_HCD_H__
+#define __MAUSB_HCD_H__
+
+#include <linux/slab.h>
+#include <linux/usb.h>
+#include <linux/usb/hcd.h>
+
+#define DEVICE_NAME "mausb_host_hcd"
+#define CLASS_NAME "mausb"
+
+#define NUMBER_OF_PORTS 15
+
+#define MAX_USB_DEVICE_DEPTH 6
+
+#define RESPONSE_TIMEOUT 5000
+
+#define MAUSB_PORT_20_STATUS_LOW_SPEED 0x0200
+#define MAUSB_PORT_20_STATUS_HIGH_SPEED 0x0400
+
+enum mausb_device_type {
+ USBDEVICE = 0,
+ USB20HUB = 1,
+ USB30HUB = 2
+};
+
+enum mausb_device_speed {
+ LOW_SPEED = 0,
+ FULL_SPEED = 1,
+ HIGH_SPEED = 2,
+ SUPER_SPEED = 3,
+ SUPER_SPEED_PLUS = 4
+};
+
+struct mausb_hcd {
+ spinlock_t lock; /* Protect HCD during URB processing */
+ struct device *pdev;
+ u16 connected_ports;
+
+ struct rb_root mausb_urbs;
+ struct hub_ctx *hcd_ss_ctx;
+ struct hub_ctx *hcd_hs_ctx;
+ struct notifier_block power_state_listener;
+};
+
+struct mausb_dev {
+ u32 port_status;
+ struct rb_root usb_devices;
+ u8 dev_speed;
+ void *ma_dev;
+};
+
+struct hub_ctx {
+ struct mausb_hcd *mhcd;
+ struct usb_hcd *hcd;
+ struct mausb_dev ma_devs[NUMBER_OF_PORTS];
+};
+
+int mausb_init_hcd(void);
+void mausb_deinit_hcd(void);
+
+#endif /* __MAUSB_HCD_H__ */
diff --git a/drivers/usb/host/mausb/mausb_core.c b/drivers/usb/host/mausb/mausb_core.c
index 44f76a1b74de..485f241d2b4c 100644
--- a/drivers/usb/host/mausb/mausb_core.c
+++ b/drivers/usb/host/mausb/mausb_core.c
@@ -4,6 +4,7 @@
*/
#include <linux/module.h>
+#include "hcd.h"
#include "utils.h"
MODULE_LICENSE("GPL");
@@ -11,12 +12,27 @@ MODULE_AUTHOR("DisplayLink (UK) Ltd.");
static int mausb_host_init(void)
{
- return mausb_host_dev_register();
+ int status = mausb_host_dev_register();
+
+ if (status < 0)
+ goto exit;
+
+ status = mausb_init_hcd();
+ if (status < 0)
+ goto cleanup_dev;
+
+ return 0;
+
+cleanup_dev:
+ mausb_host_dev_deregister();
+exit:
+ return status;
}
static void mausb_host_exit(void)
{
dev_info(mausb_host_dev.this_device, "Module unloading started...");
+ mausb_deinit_hcd();
mausb_host_dev_deregister();
}
--
2.17.1
On Fri, May 15, 2020 at 02:34:57PM +0200, Vladimir Stankovic wrote:
> Implemented HCD initialization/deinitialization functionality.
Shortest changelog ever :(
Please describe things better.
thanks,
greg k-h
On Fri, May 15, 2020 at 02:34:57PM +0200, Vladimir Stankovic wrote:
> --- /dev/null
> +++ b/drivers/usb/host/mausb/hcd.c
> @@ -0,0 +1,120 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2019 - 2020 DisplayLink (UK) Ltd.
> + */
> +#include "hcd.h"
> +
> +#include "utils.h"
> +
> +static int mausb_bus_match(struct device *dev, struct device_driver *drv);
> +
> +static const struct file_operations mausb_fops;
> +
> +static unsigned int major;
> +static unsigned int minor = 1;
> +static dev_t devt;
> +static struct device *device;
> +
> +struct mausb_hcd *mhcd;
> +static struct class *mausb_class;
> +static struct bus_type mausb_bus_type = {
> + .name = DEVICE_NAME,
> + .match = mausb_bus_match,
> +};
A static bus type??? For a single driver?
> +
> +static struct device_driver mausb_driver = {
> + .name = DEVICE_NAME,
> + .bus = &mausb_bus_type,
> + .owner = THIS_MODULE,
> +};
Wait, what??? A static "raw" struct device_driver? Why???
> +
> +static void mausb_remove(void)
> +{
> + struct usb_hcd *hcd, *shared_hcd;
> +
> + hcd = mhcd->hcd_hs_ctx->hcd;
> + shared_hcd = mhcd->hcd_ss_ctx->hcd;
> +
> + if (shared_hcd) {
> + usb_remove_hcd(shared_hcd);
> + usb_put_hcd(shared_hcd);
> + mhcd->hcd_ss_ctx = NULL;
> + }
> +
> + usb_remove_hcd(hcd);
> + usb_put_hcd(hcd);
> + mhcd->hcd_hs_ctx = NULL;
> +}
> +
> +static int mausb_bus_match(struct device *dev, struct device_driver *drv)
> +{
> + if (strncmp(dev->bus->name, drv->name, strlen(drv->name)))
> + return 0;
> + else
> + return 1;
> +}
> +
> +int mausb_init_hcd(void)
> +{
> + int retval = register_chrdev(0, DEVICE_NAME, &mausb_fops);
> +
> + if (retval < 0)
> + return retval;
> +
> + major = (unsigned int)retval;
> + retval = bus_register(&mausb_bus_type);
> + if (retval)
> + goto bus_register_error;
> +
> + mausb_class = class_create(THIS_MODULE, CLASS_NAME);
> + if (IS_ERR(mausb_class)) {
> + retval = (int)PTR_ERR(mausb_class);
> + goto class_error;
> + }
> +
> + retval = driver_register(&mausb_driver);
> + if (retval)
> + goto driver_register_error;
> +
> + mhcd = kzalloc(sizeof(*mhcd), GFP_ATOMIC);
> + if (!mhcd) {
> + retval = -ENOMEM;
> + goto mausb_hcd_alloc_failed;
> + }
> +
> + devt = MKDEV(major, minor);
> + device = device_create(mausb_class, NULL, devt, mhcd, DEVICE_NAME);
> + if (IS_ERR(device)) {
> + retval = (int)IS_ERR(device);
> + goto device_create_error;
> + }
> +
> + device->driver = &mausb_driver;
Why? What is this device going to do? What do you need it for?
> +
> + return retval;
> +device_create_error:
> + kfree(mhcd);
> + mhcd = NULL;
> +mausb_hcd_alloc_failed:
> + driver_unregister(&mausb_driver);
> +driver_register_error:
> + class_destroy(mausb_class);
> +class_error:
> + bus_unregister(&mausb_bus_type);
> +bus_register_error:
> + unregister_chrdev(major, DEVICE_NAME);
I thought you were using the misc device, what are you doing with a
class and chardev? Why is that still here?
> +
> + return retval;
> +}
> +
> +void mausb_deinit_hcd(void)
> +{
> + if (mhcd) {
> + mausb_remove();
> + device_destroy(mausb_class, devt);
> + driver_unregister(&mausb_driver);
> + class_destroy(mausb_class);
> + bus_unregister(&mausb_bus_type);
> + unregister_chrdev(major, DEVICE_NAME);
> + }
> +}
> diff --git a/drivers/usb/host/mausb/hcd.h b/drivers/usb/host/mausb/hcd.h
> new file mode 100644
> index 000000000000..e2374af67663
> --- /dev/null
> +++ b/drivers/usb/host/mausb/hcd.h
> @@ -0,0 +1,65 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2019 - 2020 DisplayLink (UK) Ltd.
> + */
> +#ifndef __MAUSB_HCD_H__
> +#define __MAUSB_HCD_H__
> +
> +#include <linux/slab.h>
> +#include <linux/usb.h>
> +#include <linux/usb/hcd.h>
> +
> +#define DEVICE_NAME "mausb_host_hcd"
> +#define CLASS_NAME "mausb"
> +
> +#define NUMBER_OF_PORTS 15
Why this max?
> +
> +#define MAX_USB_DEVICE_DEPTH 6
Where does this max come from?
> +
> +#define RESPONSE_TIMEOUT 5000
Units?
> +
> +#define MAUSB_PORT_20_STATUS_LOW_SPEED 0x0200
> +#define MAUSB_PORT_20_STATUS_HIGH_SPEED 0x0400
Device ids? Something else?
If something else, use BIT()?
> +
> +enum mausb_device_type {
> + USBDEVICE = 0,
> + USB20HUB = 1,
> + USB30HUB = 2
Trailing , please
> +};
> +
> +enum mausb_device_speed {
> + LOW_SPEED = 0,
> + FULL_SPEED = 1,
> + HIGH_SPEED = 2,
> + SUPER_SPEED = 3,
> + SUPER_SPEED_PLUS = 4
, please.
> +};
Where do these values come from?
> +
> +struct mausb_hcd {
> + spinlock_t lock; /* Protect HCD during URB processing */
> + struct device *pdev;
> + u16 connected_ports;
Why u16?
> +
> + struct rb_root mausb_urbs;
> + struct hub_ctx *hcd_ss_ctx;
> + struct hub_ctx *hcd_hs_ctx;
> + struct notifier_block power_state_listener;
> +};
> +
> +struct mausb_dev {
> + u32 port_status;
> + struct rb_root usb_devices;
> + u8 dev_speed;
> + void *ma_dev;
> +};
> +
> +struct hub_ctx {
> + struct mausb_hcd *mhcd;
> + struct usb_hcd *hcd;
> + struct mausb_dev ma_devs[NUMBER_OF_PORTS];
> +};
> +
> +int mausb_init_hcd(void);
> +void mausb_deinit_hcd(void);
> +
> +#endif /* __MAUSB_HCD_H__ */
> diff --git a/drivers/usb/host/mausb/mausb_core.c b/drivers/usb/host/mausb/mausb_core.c
> index 44f76a1b74de..485f241d2b4c 100644
> --- a/drivers/usb/host/mausb/mausb_core.c
> +++ b/drivers/usb/host/mausb/mausb_core.c
> @@ -4,6 +4,7 @@
> */
> #include <linux/module.h>
>
> +#include "hcd.h"
> #include "utils.h"
>
> MODULE_LICENSE("GPL");
> @@ -11,12 +12,27 @@ MODULE_AUTHOR("DisplayLink (UK) Ltd.");
>
> static int mausb_host_init(void)
> {
> - return mausb_host_dev_register();
> + int status = mausb_host_dev_register();
> +
> + if (status < 0)
> + goto exit;
> +
> + status = mausb_init_hcd();
> + if (status < 0)
> + goto cleanup_dev;
> +
> + return 0;
> +
> +cleanup_dev:
> + mausb_host_dev_deregister();
> +exit:
> + return status;
> }
>
> static void mausb_host_exit(void)
> {
> dev_info(mausb_host_dev.this_device, "Module unloading started...");
This is debugging statements, please remove. If a driver works
properly, it does not print anything out.
Especially as you never give the user the chance to see if module
unloading ever finished :)
thanks,
greg k-h
On 15.5.20. 15:07, Greg KH wrote:
> On Fri, May 15, 2020 at 02:34:57PM +0200, Vladimir Stankovic wrote:
>> --- /dev/null
>> +++ b/drivers/usb/host/mausb/hcd.c
>> @@ -0,0 +1,120 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Copyright (c) 2019 - 2020 DisplayLink (UK) Ltd.
>> + */
>> +#include "hcd.h"
>> +
>> +#include "utils.h"
>> +
>> +static int mausb_bus_match(struct device *dev, struct device_driver *drv);
>> +
>> +static const struct file_operations mausb_fops;
>> +
>> +static unsigned int major;
>> +static unsigned int minor = 1;
>> +static dev_t devt;
>> +static struct device *device;
>> +
>> +struct mausb_hcd *mhcd;
>> +static struct class *mausb_class;
>> +static struct bus_type mausb_bus_type = {
>> + .name = DEVICE_NAME,
>> + .match = mausb_bus_match,
>> +};
>
> A static bus type??? For a single driver?
>
>> +
>> +static struct device_driver mausb_driver = {
>> + .name = DEVICE_NAME,
>> + .bus = &mausb_bus_type,
>> + .owner = THIS_MODULE,
>> +};
>
> Wait, what??? A static "raw" struct device_driver? Why???
This was our initial driver setup that was "inherited" from some
in-tree drivers. We are currently revising driver setup. In general,
device driver will not work properly w/o bus being setup and the
only way to avoid explicit bus and simplify driver setup is to use
platform driver; however, we are not aware of any explicit dependency
on the platform, so not sure whether it's acceptable to switch to
platform device driver setup.
>
>> +
>> +static void mausb_remove(void)
>> +{
>> + struct usb_hcd *hcd, *shared_hcd;
>> +
>> + hcd = mhcd->hcd_hs_ctx->hcd;
>> + shared_hcd = mhcd->hcd_ss_ctx->hcd;
>> +
>> + if (shared_hcd) {
>> + usb_remove_hcd(shared_hcd);
>> + usb_put_hcd(shared_hcd);
>> + mhcd->hcd_ss_ctx = NULL;
>> + }
>> +
>> + usb_remove_hcd(hcd);
>> + usb_put_hcd(hcd);
>> + mhcd->hcd_hs_ctx = NULL;
>> +}
>> +
>> +static int mausb_bus_match(struct device *dev, struct device_driver *drv)
>> +{
>> + if (strncmp(dev->bus->name, drv->name, strlen(drv->name)))
>> + return 0;
>> + else
>> + return 1;
>> +}
>> +
>> +int mausb_init_hcd(void)
>> +{
>> + int retval = register_chrdev(0, DEVICE_NAME, &mausb_fops);
>> +
>> + if (retval < 0)
>> + return retval;
>> +
>> + major = (unsigned int)retval;
>> + retval = bus_register(&mausb_bus_type);
>> + if (retval)
>> + goto bus_register_error;
>> +
>> + mausb_class = class_create(THIS_MODULE, CLASS_NAME);
>> + if (IS_ERR(mausb_class)) {
>> + retval = (int)PTR_ERR(mausb_class);
>> + goto class_error;
>> + }
>> +
>> + retval = driver_register(&mausb_driver);
>> + if (retval)
>> + goto driver_register_error;
>> +
>> + mhcd = kzalloc(sizeof(*mhcd), GFP_ATOMIC);
>> + if (!mhcd) {
>> + retval = -ENOMEM;
>> + goto mausb_hcd_alloc_failed;
>> + }
>> +
>> + devt = MKDEV(major, minor);
>> + device = device_create(mausb_class, NULL, devt, mhcd, DEVICE_NAME);
>> + if (IS_ERR(device)) {
>> + retval = (int)IS_ERR(device);
>> + goto device_create_error;
>> + }
>> +
>> + device->driver = &mausb_driver;
>
> Why? What is this device going to do? What do you need it for?
Yeah, this one is not needed at all. Will be removed.
>
>> +
>> + return retval;
>> +device_create_error:
>> + kfree(mhcd);
>> + mhcd = NULL;
>> +mausb_hcd_alloc_failed:
>> + driver_unregister(&mausb_driver);
>> +driver_register_error:
>> + class_destroy(mausb_class);
>> +class_error:
>> + bus_unregister(&mausb_bus_type);
>> +bus_register_error:
>> + unregister_chrdev(major, DEVICE_NAME);
>
> I thought you were using the misc device, what are you doing with a
> class and chardev? Why is that still here?
>
We're currently revising driver setup logic - this part should be much
cleaner in new patch version.
>
>
>
>> +
>> + return retval;
>> +}
>> +
>> +void mausb_deinit_hcd(void)
>> +{
>> + if (mhcd) {
>> + mausb_remove();
>> + device_destroy(mausb_class, devt);
>> + driver_unregister(&mausb_driver);
>> + class_destroy(mausb_class);
>> + bus_unregister(&mausb_bus_type);
>> + unregister_chrdev(major, DEVICE_NAME);
>> + }
>> +}
>> diff --git a/drivers/usb/host/mausb/hcd.h b/drivers/usb/host/mausb/hcd.h
>> new file mode 100644
>> index 000000000000..e2374af67663
>> --- /dev/null
>> +++ b/drivers/usb/host/mausb/hcd.h
>> @@ -0,0 +1,65 @@
>> +/* SPDX-License-Identifier: GPL-2.0 */
>> +/*
>> + * Copyright (c) 2019 - 2020 DisplayLink (UK) Ltd.
>> + */
>> +#ifndef __MAUSB_HCD_H__
>> +#define __MAUSB_HCD_H__
>> +
>> +#include <linux/slab.h>
>> +#include <linux/usb.h>
>> +#include <linux/usb/hcd.h>
>> +
>> +#define DEVICE_NAME "mausb_host_hcd"
>> +#define CLASS_NAME "mausb"
>> +
>> +#define NUMBER_OF_PORTS 15
>
> Why this max?
Related to USB_SS_MAXPORTS - a worst case scenario.
>
>> +
>> +#define MAX_USB_DEVICE_DEPTH 6
>
> Where does this max come from?
Unknown origin and unused - will be removed.
>
>> +
>> +#define RESPONSE_TIMEOUT 5000
>
> Units?
ms - will be renamed to reflect the same.
>
>> +
>> +#define MAUSB_PORT_20_STATUS_LOW_SPEED 0x0200
>> +#define MAUSB_PORT_20_STATUS_HIGH_SPEED 0x0400
>
> Device ids? Something else?
>
> If something else, use BIT()?
>
>> +
>> +enum mausb_device_type {
>> + USBDEVICE = 0,
>> + USB20HUB = 1,
>> + USB30HUB = 2
>
> Trailing , please
>
>> +};
>> +
>> +enum mausb_device_speed {
>> + LOW_SPEED = 0,
>> + FULL_SPEED = 1,
>> + HIGH_SPEED = 2,
>> + SUPER_SPEED = 3,
>> + SUPER_SPEED_PLUS = 4
>
> , please.
>
>> +};
>
> Where do these values come from?
>
>> +
>> +struct mausb_hcd {
>> + spinlock_t lock; /* Protect HCD during URB processing */
>> + struct device *pdev;
>> + u16 connected_ports;
>
> Why u16?
Seems odd, since max number of ports is much less. Should be corrected.
>
>> +
>> + struct rb_root mausb_urbs;
>> + struct hub_ctx *hcd_ss_ctx;
>> + struct hub_ctx *hcd_hs_ctx;
>> + struct notifier_block power_state_listener;
>> +};
>> +
>> +struct mausb_dev {
>> + u32 port_status;
>> + struct rb_root usb_devices;
>> + u8 dev_speed;
>> + void *ma_dev;
>> +};
>> +
>> +struct hub_ctx {
>> + struct mausb_hcd *mhcd;
>> + struct usb_hcd *hcd;
>> + struct mausb_dev ma_devs[NUMBER_OF_PORTS];
>> +};
>> +
>> +int mausb_init_hcd(void);
>> +void mausb_deinit_hcd(void);
>> +
>> +#endif /* __MAUSB_HCD_H__ */
>> diff --git a/drivers/usb/host/mausb/mausb_core.c b/drivers/usb/host/mausb/mausb_core.c
>> index 44f76a1b74de..485f241d2b4c 100644
>> --- a/drivers/usb/host/mausb/mausb_core.c
>> +++ b/drivers/usb/host/mausb/mausb_core.c
>> @@ -4,6 +4,7 @@
>> */
>> #include <linux/module.h>
>>
>> +#include "hcd.h"
>> #include "utils.h"
>>
>> MODULE_LICENSE("GPL");
>> @@ -11,12 +12,27 @@ MODULE_AUTHOR("DisplayLink (UK) Ltd.");
>>
>> static int mausb_host_init(void)
>> {
>> - return mausb_host_dev_register();
>> + int status = mausb_host_dev_register();
>> +
>> + if (status < 0)
>> + goto exit;
>> +
>> + status = mausb_init_hcd();
>> + if (status < 0)
>> + goto cleanup_dev;
>> +
>> + return 0;
>> +
>> +cleanup_dev:
>> + mausb_host_dev_deregister();
>> +exit:
>> + return status;
>> }
>>
>> static void mausb_host_exit(void)
>> {
>> dev_info(mausb_host_dev.this_device, "Module unloading started...");
>
> This is debugging statements, please remove. If a driver works
> properly, it does not print anything out.
>
> Especially as you never give the user the chance to see if module
> unloading ever finished :)
Agree :)
>
> thanks,
>
> greg k-h
>
--
Regards,
Vladimir.
On 15.5.20. 15:03, Greg KH wrote:
> On Fri, May 15, 2020 at 02:34:57PM +0200, Vladimir Stankovic wrote:
>> Implemented HCD initialization/deinitialization functionality.
>
> Shortest changelog ever :(
>
> Please describe things better.
>
> thanks,
>
> greg k-h
>
Agree. We'll start adding a bunch of documentation and comments in
following patch versions - this was a quick fix during patchset reorg done
in initial phase of upstreaming.
--
Regards,
Vladimir.
On Thu, Jun 11, 2020 at 08:18:34PM +0200, Vladimir Stankovic wrote:
> On 15.5.20. 15:07, Greg KH wrote:
> > On Fri, May 15, 2020 at 02:34:57PM +0200, Vladimir Stankovic wrote:
> >> --- /dev/null
> >> +++ b/drivers/usb/host/mausb/hcd.c
> >> @@ -0,0 +1,120 @@
> >> +// SPDX-License-Identifier: GPL-2.0
> >> +/*
> >> + * Copyright (c) 2019 - 2020 DisplayLink (UK) Ltd.
> >> + */
> >> +#include "hcd.h"
> >> +
> >> +#include "utils.h"
> >> +
> >> +static int mausb_bus_match(struct device *dev, struct device_driver *drv);
> >> +
> >> +static const struct file_operations mausb_fops;
> >> +
> >> +static unsigned int major;
> >> +static unsigned int minor = 1;
> >> +static dev_t devt;
> >> +static struct device *device;
> >> +
> >> +struct mausb_hcd *mhcd;
> >> +static struct class *mausb_class;
> >> +static struct bus_type mausb_bus_type = {
> >> + .name = DEVICE_NAME,
> >> + .match = mausb_bus_match,
> >> +};
> >
> > A static bus type??? For a single driver?
> >
> >> +
> >> +static struct device_driver mausb_driver = {
> >> + .name = DEVICE_NAME,
> >> + .bus = &mausb_bus_type,
> >> + .owner = THIS_MODULE,
> >> +};
> >
> > Wait, what??? A static "raw" struct device_driver? Why???
> This was our initial driver setup that was "inherited" from some
> in-tree drivers. We are currently revising driver setup. In general,
> device driver will not work properly w/o bus being setup and the
> only way to avoid explicit bus and simplify driver setup is to use
> platform driver; however, we are not aware of any explicit dependency
> on the platform, so not sure whether it's acceptable to switch to
> platform device driver setup.
platform devices/drivers are to be used ONLY if your really have a
platform device (i.e. something connected to the system only through
device-tree or hard-coded memory locations.) Do not use this for
virtual devices or anything else that is on a "real" bus.
thanks,
greg k-h