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USB: serial drivers need to use larger bulk-in buffers

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When a driver doesn't know how much data a device is going to send,
the buffer size should be at least as big as the endpoint's maxpacket
value.  The serial drivers don't follow this rule; many of them
request only 256-byte bulk-in buffers.  As a result, they suffer
overflow errors if a high-speed device wants to send a lot of data,
because high-speed bulk endpoints are required to have a maxpacket
size of 512.

This patch (as1450) fixes the problem by using the driver's
bulk_in_size value as a minimum, always allocating buffers no smaller
than the endpoint's maxpacket size.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Flynn Marquardt <flynn@flynnux.de>
CC: <stable@kernel.org> [after .39-rc1 is out]
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern
2011-02-23 15:28:18 -05:00
committed by Greg Kroah-Hartman
parent 22ced6874f
commit 969e3033ae
2 changed files with 4 additions and 4 deletions
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3
include/linux/usb/serial.h
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@ -191,7 +191,8 @@ static inline void usb_set_serial_data(struct usb_serial *serial, void *data)
* @id_table: pointer to a list of usb_device_id structures that define all
* of the devices this structure can support.
* @num_ports: the number of different ports this device will have.
* @bulk_in_size: bytes to allocate for bulk-in buffer (0 = end-point size)
* @bulk_in_size: minimum number of bytes to allocate for bulk-in buffer
* (0 = end-point size)
* @bulk_out_size: bytes to allocate for bulk-out buffer (0 = end-point size)
* @calc_num_ports: pointer to a function to determine how many ports this
* device has dynamically. It will be called after the probe()