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Date: Mon, 10 Jun 2019 06:33:29 +0000
From: Pawel Laszczak <pawell@...ence.com>
To: Heikki Krogerus <heikki.krogerus@...ux.intel.com>
CC: "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
"gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>,
"felipe.balbi@...ux.intel.com" <felipe.balbi@...ux.intel.com>,
"linux-usb@...r.kernel.org" <linux-usb@...r.kernel.org>,
"hdegoede@...hat.com" <hdegoede@...hat.com>,
"robh+dt@...nel.org" <robh+dt@...nel.org>,
"rogerq@...com" <rogerq@...com>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"jbergsagel@...com" <jbergsagel@...com>,
"nsekhar@...com" <nsekhar@...com>, "nm@...com" <nm@...com>,
Suresh Punnoose <sureshp@...ence.com>,
"peter.chen@....com" <peter.chen@....com>,
Jayshri Dajiram Pawar <jpawar@...ence.com>,
Rahul Kumar <kurahul@...ence.com>
Subject: RE: [PATCH v7 5/6] usb:cdns3 Add Cadence USB3 DRD Driver
>On Wed, Jun 05, 2019 at 11:03:49AM +0100, Pawel Laszczak wrote:
>> diff --git a/drivers/usb/cdns3/debugfs.c b/drivers/usb/cdns3/debugfs.c
>> new file mode 100644
>> index 000000000000..dfcbeb5e14f8
>> --- /dev/null
>> +++ b/drivers/usb/cdns3/debugfs.c
>> @@ -0,0 +1,173 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * Cadence USBSS DRD Controller DebugFS filer.
>> + *
>> + * Copyright (C) 2018-2019 Cadence.
>> + *
>> + * Author: Pawel Laszczak <pawell@...ence.com>
>> + */
>> +
>> +#include <linux/types.h>
>> +#include <linux/debugfs.h>
>> +#include <linux/seq_file.h>
>> +#include <linux/uaccess.h>
>> +
>> +#include "core.h"
>> +#include "gadget.h"
>> +#include "drd.h"
>
>static const char *const cdns3_mode[] = {
> [USB_DR_MODE_UNKNOWN] = "unknown",
> [USB_DR_MODE_OTG] = "otg",
> [USB_DR_MODE_HOST] = "host",
> [USB_DR_MODE_PERIPHERAL] = "device",
>};
>
>> +static int cdns3_mode_show(struct seq_file *s, void *unused)
>> +{
>> + struct cdns3 *cdns = s->private;
>> +
>> + switch (cdns->current_dr_mode) {
>> + case USB_DR_MODE_HOST:
>> + seq_puts(s, "host\n");
>> + break;
>> + case USB_DR_MODE_PERIPHERAL:
>> + seq_puts(s, "device\n");
>> + break;
>> + case USB_DR_MODE_OTG:
>> + seq_puts(s, "otg\n");
>> + break;
>> + default:
>> + seq_puts(s, "UNKNOWN mode\n");
>> + }
>
>All you should need here is:
>
> seq_puts(s, cdns3_mode[cdns->current_dr_mode]);
>
>> + return 0;
>> +}
>> +
>> +static int cdns3_mode_open(struct inode *inode, struct file *file)
>> +{
>> + return single_open(file, cdns3_mode_show, inode->i_private);
>> +}
>> +
>> +static ssize_t cdns3_mode_write(struct file *file,
>> + const char __user *ubuf,
>> + size_t count, loff_t *ppos)
>> +{
>> + struct seq_file *s = file->private_data;
>> + struct cdns3 *cdns = s->private;
>> + u32 mode = USB_DR_MODE_UNKNOWN;
>> + char buf[32];
>> + int ret = 0;
>
> int ret;
>
>> + if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
>> + return -EFAULT;
>
> return -EINVAL;
Why? I've checked in some place in kernel and after copy_from_user are used EFAULT.
I think that EINVAL is better but I wanted be consistent with the rest of kernel.
Is there any explanation for this ?
>
>> +
>> + if (cdns->debug_disable) {
>> + dev_err(cdns->dev,
>> + "Mode can't be changed when disable is set\n");
>> + return -EFAULT;
>
> return -EPERM;
>
>> + }
>> +
>> + if (!strncmp(buf, "host", 4)) {
>> + if (cdns->dr_mode == USB_DR_MODE_HOST ||
>> + cdns->dr_mode == USB_DR_MODE_OTG) {
>> + mode = USB_DR_MODE_HOST;
>> + }
>> + }
>> +
>> + if (!strncmp(buf, "device", 6))
>> + if (cdns->dr_mode == USB_DR_MODE_PERIPHERAL ||
>> + cdns->dr_mode == USB_DR_MODE_OTG)
>> + mode = USB_DR_MODE_PERIPHERAL;
>> +
>> + if (!strncmp(buf, "otg", 3) && cdns->dr_mode == USB_DR_MODE_OTG)
>> + mode = USB_DR_MODE_OTG;
>> +
>> + if (mode == USB_DR_MODE_UNKNOWN) {
>> + dev_err(cdns->dev, "Failed: incorrect mode setting\n");
>> + return -EFAULT;
>> + }
>
>To cover all those, you just need to:
>
> ret = match_string(cdns3_mode, ARRAY_SIZE(cdns3_mode), buf));
> if (ret < 0 || ret == USB_DR_MODE_UNKNOWN)
> return -EINVAL;
>
>> + if (cdns->current_dr_mode != mode) {
>> + cdns->desired_dr_mode = mode;
>
> if (cdns->current_dr_mode != ret)
> cdns->desired_dr_mode = ret;
>
>> + cdns3_role_stop(cdns);
>> + ret = cdns3_drd_update_mode(cdns);
>> + if (ret)
>> + return ret;
>> +
>> + queue_work(system_freezable_wq, &cdns->role_switch_wq);
>> + }
>> +
>> + return count;
>> +}
>> +
>> +static const struct file_operations cdns3_mode_fops = {
>> + .open = cdns3_mode_open,
>> + .write = cdns3_mode_write,
>> + .read = seq_read,
>> + .llseek = seq_lseek,
>> + .release = single_release,
>> +};
>> +
>> +static int cdns3_disable_show(struct seq_file *s, void *unused)
>> +{
>> + struct cdns3 *cdns = s->private;
>> +
>> + if (!cdns->debug_disable)
>> + seq_puts(s, "0\n");
>> + else
>> + seq_puts(s, "1\n");
>> +
>> + return 0;
>> +}
>> +
>> +static ssize_t cdns3_disable_write(struct file *file,
>> + const char __user *ubuf,
>> + size_t count, loff_t *ppos)
>> +{
>> + struct seq_file *s = file->private_data;
>> + struct cdns3 *cdns = s->private;
>> + bool disable;
>> + char buf[16];
>> +
>> + if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
>> + return -EFAULT;
>> +
>> + if (kstrtobool(buf, &disable)) {
>> + dev_err(cdns->dev, "wrong setting\n");
>> + return -EINVAL;
>> + }
>> +
>> + if (disable != cdns->debug_disable) {
>> + cdns->debug_disable = disable;
>> + queue_work(system_freezable_wq, &cdns->role_switch_wq);
>> + }
>> +
>> + return count;
>> +}
>> +
>> +static int cdns3_disable_open(struct inode *inode, struct file *file)
>> +{
>> + return single_open(file, cdns3_disable_show, inode->i_private);
>> +}
>> +
>> +static const struct file_operations cdns3_disable_fops = {
>> + .open = cdns3_disable_open,
>> + .write = cdns3_disable_write,
>> + .read = seq_read,
>> + .llseek = seq_lseek,
>> + .release = single_release,
>> +};
>> +
>> +void cdns3_debugfs_init(struct cdns3 *cdns)
>> +{
>> + struct dentry *root;
>> +
>> + root = debugfs_create_dir(dev_name(cdns->dev), NULL);
>> + cdns->root = root;
>> + if (IS_ENABLED(CONFIG_USB_CDNS3_GADGET) &&
>> + IS_ENABLED(CONFIG_USB_CDNS3_HOST))
>> + debugfs_create_file("mode", 0644, root, cdns,
>> + &cdns3_mode_fops);
>> +
>> + debugfs_create_file("disable", 0644, root, cdns,
>> + &cdns3_disable_fops);
>> +}
>> +
>> +void cdns3_debugfs_exit(struct cdns3 *cdns)
>> +{
>> + debugfs_remove_recursive(cdns->root);
>> +}
>
>thanks,
>
>--
>heikki
Thank for nice simplification.
Regards
Pawel
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