grub2/0120-Split-long-USB-transfers-into-short-ones.patch
2013-06-07 14:03:56 -04:00

72 lines
2.2 KiB
Diff

From 2c1ea139e754820b55f58bdc32f3376671c453db Mon Sep 17 00:00:00 2001
From: Vladimir 'phcoder' Serbinenko <phcoder@gmail.com>
Date: Sun, 20 Jan 2013 22:45:53 +0100
Subject: [PATCH 120/471] Split long USB transfers into short ones.
---
ChangeLog | 4 ++++
grub-core/bus/usb/usbtrans.c | 20 ++++++++++++++++----
include/grub/usbtrans.h | 2 ++
3 files changed, 22 insertions(+), 4 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index 4d09825..c8edf73 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2013-01-20 Aleš Nesrsta <starous@volny.cz>
+
+ Split long USB transfers into short ones.
+
2013-01-20 Andrey Borzenkov <arvidjaar@gmail.com>
* docs/grub.texi (Simple configuration): Clarify GRUB_HIDDEN_TIMEOUT
diff --git a/grub-core/bus/usb/usbtrans.c b/grub-core/bus/usb/usbtrans.c
index 167fae5..154c72d 100644
--- a/grub-core/bus/usb/usbtrans.c
+++ b/grub-core/bus/usb/usbtrans.c
@@ -351,11 +351,23 @@ grub_usb_err_t
grub_usb_bulk_read (grub_usb_device_t dev,
int endpoint, grub_size_t size, char *data)
{
- grub_size_t actual;
+ grub_size_t actual, transferred;
grub_usb_err_t err;
- err = grub_usb_bulk_readwrite (dev, endpoint, size, data,
- GRUB_USB_TRANSFER_TYPE_IN, 1000, &actual);
- if (!err && actual != size)
+ grub_size_t current_size, position;
+
+ for (position = 0, transferred = 0;
+ position < size; position += MAX_USB_TRANSFER_LEN)
+ {
+ current_size = size - position;
+ if (current_size >= MAX_USB_TRANSFER_LEN)
+ current_size = MAX_USB_TRANSFER_LEN;
+ err = grub_usb_bulk_readwrite (dev, endpoint, current_size,
+ &data[position], GRUB_USB_TRANSFER_TYPE_IN, 1000, &actual);
+ transferred += actual;
+ if (err || (current_size != actual) ) break;
+ }
+
+ if (!err && transferred != size)
err = GRUB_USB_ERR_DATA;
return err;
}
diff --git a/include/grub/usbtrans.h b/include/grub/usbtrans.h
index 5ee276d..5429007 100644
--- a/include/grub/usbtrans.h
+++ b/include/grub/usbtrans.h
@@ -19,6 +19,8 @@
#ifndef GRUB_USBTRANS_H
#define GRUB_USBTRANS_H 1
+#define MAX_USB_TRANSFER_LEN 0x0800
+
typedef enum
{
GRUB_USB_TRANSFER_TYPE_IN,
--
1.8.2.1