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authorAlan Stern <stern@rowland.harvard.edu>2010-05-05 15:26:17 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2010-05-20 13:21:42 -0700
commit0ba169aff9181389f30f225ad92e113eeb2290b9 (patch)
tree50dc210826805224c8b2941dfcfbf55ffb4e3c02 /drivers/usb/core
parenta9914127e834acf648a96c72b4e271dc0c1c7c74 (diff)
USB: simplify usb_sg_init()
This patch (as1377) simplifies the code in usb_sg_init(), without changing its functionality. It also removes a couple of unused fields from the usb_sg_request structure. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/core')
-rw-r--r--drivers/usb/core/message.c93
1 files changed, 38 insertions, 55 deletions
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 63919b8abee1..a73e08fdab36 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -371,79 +371,64 @@ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
spin_lock_init(&io->lock);
io->dev = dev;
io->pipe = pipe;
- io->sg = sg;
- io->nents = nents;
- io->entries = nents;
- /* initialize all the urbs we'll use */
if (dev->bus->sg_tablesize > 0) {
- io->urbs = kmalloc(sizeof *io->urbs, mem_flags);
use_sg = true;
+ io->entries = 1;
} else {
- io->urbs = kmalloc(io->entries * sizeof *io->urbs, mem_flags);
use_sg = false;
+ io->entries = nents;
}
+
+ /* initialize all the urbs we'll use */
+ io->urbs = kmalloc(io->entries * sizeof *io->urbs, mem_flags);
if (!io->urbs)
goto nomem;
- urb_flags = 0;
+ urb_flags = URB_NO_INTERRUPT;
if (usb_pipein(pipe))
urb_flags |= URB_SHORT_NOT_OK;
- if (use_sg) {
- io->urbs[0] = usb_alloc_urb(0, mem_flags);
- if (!io->urbs[0]) {
- io->entries = 0;
- goto nomem;
- }
-
- io->urbs[0]->dev = NULL;
- io->urbs[0]->pipe = pipe;
- io->urbs[0]->interval = period;
- io->urbs[0]->transfer_flags = urb_flags;
+ for_each_sg(sg, sg, io->entries, i) {
+ struct urb *urb;
+ unsigned len;
- io->urbs[0]->complete = sg_complete;
- io->urbs[0]->context = io;
-
- /* A length of zero means transfer the whole sg list */
- io->urbs[0]->transfer_buffer_length = length;
- if (length == 0) {
- for_each_sg(sg, sg, io->entries, i) {
- io->urbs[0]->transfer_buffer_length +=
- sg->length;
- }
+ urb = usb_alloc_urb(0, mem_flags);
+ if (!urb) {
+ io->entries = i;
+ goto nomem;
}
- io->urbs[0]->sg = sg;
- io->urbs[0]->num_sgs = io->entries;
- io->entries = 1;
- } else {
- urb_flags |= URB_NO_INTERRUPT;
- for_each_sg(sg, sg, io->entries, i) {
- unsigned len;
-
- io->urbs[i] = usb_alloc_urb(0, mem_flags);
- if (!io->urbs[i]) {
- io->entries = i;
- goto nomem;
+ io->urbs[i] = urb;
+
+ urb->dev = NULL;
+ urb->pipe = pipe;
+ urb->interval = period;
+ urb->transfer_flags = urb_flags;
+ urb->complete = sg_complete;
+ urb->context = io;
+ urb->sg = sg;
+
+ if (use_sg) {
+ /* There is no single transfer buffer */
+ urb->transfer_buffer = NULL;
+ urb->num_sgs = nents;
+
+ /* A length of zero means transfer the whole sg list */
+ len = length;
+ if (len == 0) {
+ for_each_sg(sg, sg, nents, i)
+ len += sg->length;
}
-
- io->urbs[i]->dev = NULL;
- io->urbs[i]->pipe = pipe;
- io->urbs[i]->interval = period;
- io->urbs[i]->transfer_flags = urb_flags;
-
- io->urbs[i]->complete = sg_complete;
- io->urbs[i]->context = io;
-
+ } else {
/*
* Some systems can't use DMA; they use PIO instead.
* For their sakes, transfer_buffer is set whenever
* possible.
*/
if (!PageHighMem(sg_page(sg)))
- io->urbs[i]->transfer_buffer = sg_virt(sg);
+ urb->transfer_buffer = sg_virt(sg);
else
- io->urbs[i]->transfer_buffer = NULL;
+ urb->transfer_buffer = NULL;
len = sg->length;
if (length) {
@@ -452,12 +437,10 @@ int usb_sg_init(struct usb_sg_request *io, struct usb_device *dev,
if (length == 0)
io->entries = i + 1;
}
- io->urbs[i]->transfer_buffer_length = len;
-
- io->urbs[i]->sg = sg;
}
- io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT;
+ urb->transfer_buffer_length = len;
}
+ io->urbs[--i]->transfer_flags &= ~URB_NO_INTERRUPT;
/* transaction state */
io->count = io->entries;