>
> > > So I'd prefer two buffers for cleaness' sake.
> >
> > Hmm, the read and write buffers are 8Kbytes each ... what was
> > the architecture that shared 16 Kbyte cachelines? :)
>
> Are you sure they are aligned?
> There otherwise would still be a problem at the edges.
>
> > Actually, for those buffers I'd prefer to see the
> > buffers allocated using usb_buffer_alloc(), so
> > that on architectures that have DMA restrictions
> > (SA-1111 for example) there'd be no extra "bounce"
> > through a temporary DMA buffer.
>
> Yes, that's even better.
and here it is. Please check it for correct usage of
usb_buffer_alloc() and transfer_flags.
It works (it prints -> writebuf/writeurb etc are working),
but I'd like to hear that I didn't abuse it before asking
Greg to apply it.
(patch is to 2.5.46; hopefully works for 2.5.47)
~Randy
--- ./drivers/usb/class/usblp.c%hang Mon Nov 4 14:30:11 2002
+++ ./drivers/usb/class/usblp.c Mon Nov 11 19:55:27 2002
@@ -1,9 +1,9 @@
/*
- * usblp.c Version 0.12
+ * usblp.c Version 0.13
*
* Copyright (c) 1999 Michael Gee <[EMAIL PROTECTED]>
* Copyright (c) 1999 Pavel Machek <[EMAIL PROTECTED]>
- * Copyright (c) 2000 Randy Dunlap <[EMAIL PROTECTED]>
+ * Copyright (c) 2000 Randy Dunlap <[EMAIL PROTECTED]>
* Copyright (c) 2000 Vojtech Pavlik <[EMAIL PROTECTED]>
# Copyright (c) 2001 Pete Zaitcev <[EMAIL PROTECTED]>
# Copyright (c) 2001 David Paschal <[EMAIL PROTECTED]>
@@ -25,6 +25,8 @@
* v0.10- remove sleep_on, fix error on oom ([EMAIL PROTECTED])
* v0.11 - add proto_bias option (Pete Zaitcev)
* v0.12 - add hpoj.sourceforge.net ioctls (David Paschal)
+ * v0.13 - alloc space for statusbuf (<status> not on stack);
+ * use usb_buffer_alloc() for read buf & write buf;
*/
/*
@@ -59,7 +61,7 @@
/*
* Version Information
*/
-#define DRIVER_VERSION "v0.12"
+#define DRIVER_VERSION "v0.13"
#define DRIVER_AUTHOR "Michael Gee, Pavel Machek, Vojtech Pavlik, Randy Dunlap, Pete
Zaitcev, David Paschal"
#define DRIVER_DESC "USB Printer Device Class driver"
@@ -120,11 +122,19 @@
#define USBLP_LAST_PROTOCOL 3
#define USBLP_MAX_PROTOCOLS (USBLP_LAST_PROTOCOL+1)
+/*
+ * some arbitrary status buffer size;
+ * need a status buffer that is allocated via kmalloc(), not on stack
+ */
+#define STATUS_BUF_SIZE 8
+
struct usblp {
struct usb_device *dev; /* USB device */
devfs_handle_t devfs; /* devfs device */
struct semaphore sem; /* locks this struct,
especially "dev" */
- char *buf; /* writeurb->transfer_buffer */
+ char *writebuf; /* write transfer_buffer */
+ char *readbuf; /* read transfer_buffer */
+ char *statusbuf; /* status transfer_buffer */
struct urb *readurb, *writeurb; /* The urbs */
wait_queue_head_t wait; /* Zzzzz ... */
int readcount; /* Counter for reads */
@@ -289,13 +299,14 @@
unsigned char status, newerr = 0;
int error;
- error = usblp_read_status (usblp, &status);
+ error = usblp_read_status (usblp, usblp->statusbuf);
if (error < 0) {
err("usblp%d: error %d reading printer status",
usblp->minor, error);
return 0;
}
+ status = *usblp->statusbuf;
if (~status & LP_PERRORP) {
newerr = 3;
if (status & LP_POUTPA) newerr = 1;
@@ -375,8 +386,12 @@
usb_deregister_dev (1, usblp->minor);
info("usblp%d: removed", usblp->minor);
- kfree (usblp->writeurb->transfer_buffer);
+ usb_buffer_free (usblp->dev, USBLP_BUF_SIZE,
+ usblp->writebuf, usblp->writeurb->transfer_dma);
+ usb_buffer_free (usblp->dev, USBLP_BUF_SIZE,
+ usblp->readbuf, usblp->writeurb->transfer_dma);
kfree (usblp->device_id_string);
+ kfree (usblp->statusbuf);
usb_free_urb(usblp->writeurb);
usb_free_urb(usblp->readurb);
kfree (usblp);
@@ -841,11 +856,27 @@
goto abort_minor;
}
- /* Malloc write/read buffers in one chunk. We somewhat wastefully
+ usblp->writebuf = usblp->readbuf = NULL;
+ usblp->writeurb->transfer_flags = URB_NO_DMA_MAP;
+ usblp->readurb->transfer_flags = URB_NO_DMA_MAP;
+ /* Malloc write & read buffers. We somewhat wastefully
* malloc both regardless of bidirectionality, because the
* alternate setting can be changed later via an ioctl. */
- if (!(usblp->buf = kmalloc(2 * USBLP_BUF_SIZE, GFP_KERNEL))) {
- err("out of memory for buf");
+ if (!(usblp->writebuf = usb_buffer_alloc(dev, USBLP_BUF_SIZE,
+ GFP_KERNEL, &usblp->writeurb->transfer_dma))) {
+ err("out of memory for write buf");
+ goto abort_minor;
+ }
+ if (!(usblp->readbuf = usb_buffer_alloc(dev, USBLP_BUF_SIZE,
+ GFP_KERNEL, &usblp->readurb->transfer_dma))) {
+ err("out of memory for read buf");
+ goto abort_minor;
+ }
+
+ /* Allocate buffer for printer status */
+ usblp->statusbuf = kmalloc(STATUS_BUF_SIZE, GFP_KERNEL);
+ if (!usblp->statusbuf) {
+ err("out of memory for statusbuf");
goto abort_minor;
}
@@ -900,10 +931,16 @@
usb_deregister_dev (1, usblp->minor);
abort:
if (usblp) {
+ if (usblp->writebuf)
+ usb_buffer_free (usblp->dev, USBLP_BUF_SIZE,
+ usblp->writebuf, usblp->writeurb->transfer_dma);
+ if (usblp->readbuf)
+ usb_buffer_free (usblp->dev, USBLP_BUF_SIZE,
+ usblp->readbuf, usblp->writeurb->transfer_dma);
+ if (usblp->statusbuf) kfree(usblp->statusbuf);
+ if (usblp->device_id_string) kfree(usblp->device_id_string);
usb_free_urb(usblp->writeurb);
usb_free_urb(usblp->readurb);
- if (usblp->buf) kfree(usblp->buf);
- if (usblp->device_id_string) kfree(usblp->device_id_string);
kfree(usblp);
}
return -EIO;
@@ -1020,16 +1057,16 @@
usb_fill_bulk_urb(usblp->writeurb, usblp->dev,
usb_sndbulkpipe(usblp->dev,
- usblp->protocol[protocol].epwrite->bEndpointAddress),
- usblp->buf, 0,
+ usblp->protocol[protocol].epwrite->bEndpointAddress),
+ usblp->writebuf, 0,
usblp_bulk_write, usblp);
usblp->bidir = (usblp->protocol[protocol].epread != 0);
if (usblp->bidir)
usb_fill_bulk_urb(usblp->readurb, usblp->dev,
usb_rcvbulkpipe(usblp->dev,
- usblp->protocol[protocol].epread->bEndpointAddress),
- usblp->buf + USBLP_BUF_SIZE, USBLP_BUF_SIZE,
+ usblp->protocol[protocol].epread->bEndpointAddress),
+ usblp->readbuf, USBLP_BUF_SIZE,
usblp_bulk_read, usblp);
usblp->current_protocol = protocol;
