From: yangkai <yangkai@ubuntu-fs>
Date: Wed, 31 Aug 2011 02:24:26 +0000 (+0800)
Subject: change msc buffer flush depends on usb packets
X-Git-Tag: firefly_0821_release~9767^2~77
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=6a8deefc1c0669dc4a273324c61b0003ac2bb607;p=firefly-linux-kernel-4.4.55.git

change msc buffer flush depends on usb packets
---

diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
old mode 100644
new mode 100755
index 71798209bc83..32bf6fcc625e
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -84,7 +84,8 @@
 #define BULK_BUFFER_SIZE           16384 * 4//4096
 
 /* flush after every 4 meg of writes to avoid excessive block level caching */
-#define MAX_UNFLUSHED_BYTES  (512 * 1024)// (4 * 1024 * 1024) //original value is 4MB,Modifyed by xbw at 2011-08-18
+//#define MAX_UNFLUSHED_BYTES  (512 * 1024)// (4 * 1024 * 1024) //original value is 4MB,Modifyed by xbw at 2011-08-18
+#define MAX_UNFLUSHED_PACKETS 16
 
 /*-------------------------------------------------------------------------*/
 
@@ -233,7 +234,7 @@ struct lun {
 	struct file	*filp;
 	loff_t		file_length;
 	loff_t		num_sectors;
-	unsigned int unflushed_bytes;
+	unsigned int unflushed_packet;
 
 	unsigned int	ro : 1;
 	unsigned int	prevent_medium_removal : 1;
@@ -1079,10 +1080,10 @@ static int do_write(struct fsg_dev *fsg)
 			fsg->residue -= nwritten;
 
 #ifdef MAX_UNFLUSHED_BYTES
-			curlun->unflushed_bytes += nwritten;
-			if (curlun->unflushed_bytes >= MAX_UNFLUSHED_BYTES) {
+			curlun->unflushed_packet ++;
+			if (curlun->unflushed_packet >= MAX_UNFLUSHED_PACKETS) {
 				fsync_sub(curlun);
-				curlun->unflushed_bytes = 0;
+				curlun->unflushed_packet = 0;
 			}
 #endif
 			/* If an error occurred, report it and its position */
@@ -2754,7 +2755,7 @@ static int open_backing_file(struct fsg_dev *fsg, struct lun *curlun,
 	curlun->ro = ro;
 	curlun->filp = filp;
 	curlun->file_length = size;
-	curlun->unflushed_bytes = 0;
+	curlun->unflushed_packet = 0;
 	curlun->num_sectors = num_sectors;
 	LDBG(curlun, "open backing file: %s size: %lld num_sectors: %lld\n",
 			filename, size, num_sectors);