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author | Alan Stern <stern@rowland.harvard.edu> | 2010-05-05 15:26:17 -0400 |
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committer | Greg Kroah-Hartman <gregkh@suse.de> | 2010-05-20 13:21:42 -0700 |
commit | 0ba169aff9181389f30f225ad92e113eeb2290b9 (patch) | |
tree | 50dc210826805224c8b2941dfcfbf55ffb4e3c02 /drivers/usb/core/message.c | |
parent | a9914127e834acf648a96c72b4e271dc0c1c7c74 (diff) | |
download | linux-stable-0ba169aff9181389f30f225ad92e113eeb2290b9.tar.gz linux-stable-0ba169aff9181389f30f225ad92e113eeb2290b9.tar.bz2 linux-stable-0ba169aff9181389f30f225ad92e113eeb2290b9.zip |
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/message.c')
-rw-r--r-- | drivers/usb/core/message.c | 93 |
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; |