From 606206c271722d613b99c737ce150f58f4485f41 Mon Sep 17 00:00:00 2001 From: Michal Nazarewicz Date: Wed, 28 Oct 2009 16:57:21 +0100 Subject: [PATCH] USB: g_mass_storage: constant length buffers used Using version of fsg_buffhd structure with buf field being an array of characters with predefined size. Since mass storage function does not define changing buffer size on run-time it is not required for the field to be a pointer to void and allocating space dynamically. Signed-off-by: Michal Nazarewicz Cc: David Brownell Cc: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/f_mass_storage.c | 31 +++++++++++-------------------- drivers/usb/gadget/storage_common.c | 10 ++++++++++ 2 files changed, 21 insertions(+), 20 deletions(-) diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c index 7750346..b4ec76a 100644 --- a/drivers/usb/gadget/f_mass_storage.c +++ b/drivers/usb/gadget/f_mass_storage.c @@ -258,6 +258,7 @@ static const char fsg_string_interface[] = "Mass Storage"; #define FSG_NO_INTR_EP 1 +#define FSG_BUFFHD_STATIC_BUFFER 1 #include "storage_common.c" @@ -1894,9 +1895,8 @@ static int send_status(struct fsg_dev *fsg) SK(sd), ASC(sd), ASCQ(sd), sdinfo); } - /* Store and send the Bulk-only CSW */ - csw = bh->buf; + csw = (void*)bh->buf; csw->Signature = cpu_to_le32(USB_BULK_CS_SIG); csw->Tag = fsg->tag; @@ -2808,10 +2808,6 @@ static void /* __init_or_exit */ fsg_unbind(struct usb_gadget *gadget) complete(&fsg->thread_notifier); } - /* Free the data buffers */ - for (i = 0; i < FSG_NUM_BUFFERS; ++i) - kfree(fsg->common->buffhds[i].buf); - /* Free the request and buffer for endpoint 0 */ if (req) { kfree(req->buf); @@ -2978,20 +2974,6 @@ static int __init fsg_bind(struct usb_gadget *gadget) goto out; req->complete = ep0_complete; - /* Allocate the data buffers */ - for (i = 0; i < FSG_NUM_BUFFERS; ++i) { - struct fsg_buffhd *bh = &fsg->common->buffhds[i]; - - /* Allocate for the bulk-in endpoint. We assume that - * the buffer will also work with the bulk-out (and - * interrupt-in) endpoint. */ - bh->buf = kmalloc(FSG_BUFLEN, GFP_KERNEL); - if (!bh->buf) - goto out; - bh->next = bh + 1; - } - fsg->common->buffhds[FSG_NUM_BUFFERS - 1].next = &fsg->common->buffhds[0]; - /* This should reflect the actual gadget power source */ usb_gadget_set_selfpowered(gadget); @@ -3087,6 +3069,8 @@ static struct usb_gadget_driver fsg_driver = { static int __init fsg_alloc(void) { struct fsg_dev *fsg; + struct fsg_buffhd *bh; + unsigned i; fsg = kzalloc(sizeof *fsg, GFP_KERNEL); if (!fsg) @@ -3098,6 +3082,13 @@ static int __init fsg_alloc(void) return -ENOMEM; } + bh = fsg->common->buffhds; + i = FSG_NUM_BUFFERS - 1; + do { + bh->next = bh + 1; + } while (++bh, --i); + bh->next = fsg->common->buffhds; + spin_lock_init(&fsg->lock); init_rwsem(&fsg->common->filesem); init_completion(&fsg->thread_notifier); diff --git a/drivers/usb/gadget/storage_common.c b/drivers/usb/gadget/storage_common.c index e76c8ce..60bc696 100644 --- a/drivers/usb/gadget/storage_common.c +++ b/drivers/usb/gadget/storage_common.c @@ -47,6 +47,12 @@ * When FSG_NO_OTG is defined fsg_otg_desc won't be defined. */ +/* + * When FSG_BUFFHD_STATIC_BUFFER is defined when this file is included + * the fsg_buffhd structure's buf field will be an array of FSG_BUFLEN + * characters rather then a pointer to void. + */ + #include @@ -290,7 +296,11 @@ enum fsg_buffer_state { }; struct fsg_buffhd { +#ifdef FSG_BUFFHD_STATIC_BUFFER + char buf[FSG_BUFLEN]; +#else void *buf; +#endif enum fsg_buffer_state state; struct fsg_buffhd *next; -- 2.7.4