USB: ehci-dbg: increase debug buffer size for periodic file
This patch is based on the following ideas:
1. Some usb devices (such as usb video class) have endpoints of high
interval attribute, so reading "periodic" file need more debug buffer
to accommodate the qh or itd schedule information. For example, 4KB
buffer is not enough for a single interrupt qh of 2ms period.
2. print a %p need 16 byte buffer on 64-bits arch, but 8 byte on 32-bits
arch. Add a extra bonus for 64-bits arch.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/ehci-dbg.c b/drivers/usb/host/ehci-dbg.c
index b0f8ed5..9534ff3 100644
--- a/drivers/usb/host/ehci-dbg.c
+++ b/drivers/usb/host/ehci-dbg.c
@@ -358,7 +358,8 @@
struct usb_bus *bus;
struct mutex mutex; /* protect filling of buffer */
size_t count; /* number of characters filled into buffer */
- char *page;
+ char *output_buf;
+ size_t alloc_size;
};
#define speed_char(info1) ({ char tmp; \
@@ -488,8 +489,8 @@
hcd = bus_to_hcd(buf->bus);
ehci = hcd_to_ehci (hcd);
- next = buf->page;
- size = PAGE_SIZE;
+ next = buf->output_buf;
+ size = buf->alloc_size;
*next = 0;
@@ -510,7 +511,7 @@
}
spin_unlock_irqrestore (&ehci->lock, flags);
- return strlen(buf->page);
+ return strlen(buf->output_buf);
}
#define DBG_SCHED_LIMIT 64
@@ -531,8 +532,8 @@
hcd = bus_to_hcd(buf->bus);
ehci = hcd_to_ehci (hcd);
- next = buf->page;
- size = PAGE_SIZE;
+ next = buf->output_buf;
+ size = buf->alloc_size;
temp = scnprintf (next, size, "size = %d\n", ehci->periodic_size);
size -= temp;
@@ -649,7 +650,7 @@
spin_unlock_irqrestore (&ehci->lock, flags);
kfree (seen);
- return PAGE_SIZE - size;
+ return buf->alloc_size - size;
}
#undef DBG_SCHED_LIMIT
@@ -665,8 +666,8 @@
hcd = bus_to_hcd(buf->bus);
ehci = hcd_to_ehci (hcd);
- next = buf->page;
- size = PAGE_SIZE;
+ next = buf->output_buf;
+ size = buf->alloc_size;
spin_lock_irqsave (&ehci->lock, flags);
@@ -808,7 +809,7 @@
done:
spin_unlock_irqrestore (&ehci->lock, flags);
- return PAGE_SIZE - size;
+ return buf->alloc_size - size;
}
static struct debug_buffer *alloc_buffer(struct usb_bus *bus,
@@ -822,6 +823,7 @@
buf->bus = bus;
buf->fill_func = fill_func;
mutex_init(&buf->mutex);
+ buf->alloc_size = PAGE_SIZE;
}
return buf;
@@ -831,10 +833,10 @@
{
int ret = 0;
- if (!buf->page)
- buf->page = (char *)get_zeroed_page(GFP_KERNEL);
+ if (!buf->output_buf)
+ buf->output_buf = (char *)vmalloc(buf->alloc_size);
- if (!buf->page) {
+ if (!buf->output_buf) {
ret = -ENOMEM;
goto out;
}
@@ -867,7 +869,7 @@
mutex_unlock(&buf->mutex);
ret = simple_read_from_buffer(user_buf, len, offset,
- buf->page, buf->count);
+ buf->output_buf, buf->count);
out:
return ret;
@@ -879,8 +881,8 @@
struct debug_buffer *buf = file->private_data;
if (buf) {
- if (buf->page)
- free_page((unsigned long)buf->page);
+ if (buf->output_buf)
+ vfree(buf->output_buf);
kfree(buf);
}
@@ -895,10 +897,14 @@
static int debug_periodic_open(struct inode *inode, struct file *file)
{
- file->private_data = alloc_buffer(inode->i_private,
- fill_periodic_buffer);
+ struct debug_buffer *buf;
+ buf = alloc_buffer(inode->i_private, fill_periodic_buffer);
+ if (!buf)
+ return -ENOMEM;
- return file->private_data ? 0 : -ENOMEM;
+ buf->alloc_size = (sizeof(void *) == 4 ? 6 : 8)*PAGE_SIZE;
+ file->private_data = buf;
+ return 0;
}
static int debug_registers_open(struct inode *inode, struct file *file)