common: usb_storage : Implement logic to calculate optimal usb maximum trasfer blocks

PATCH Superseded Rajesh Bhagat 2 participants 4 messages Jun 2, 2016 – Jun 6, 2016

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Rajesh Bhagat

author

2016-06-02 04:56 UTC #0 lore raw

PATCH v2 1/1 common: usb_storage : Implement logic to calculate optimal usb maximum trasfer blocks

Implements the logic to calculate the optimal usb maximum trasfer blocks instead of sending USB_MAX_XFER_BLK blocks which is 65535 and 20 in case of EHCI and other USB protocols respectively.

It defines USB_MIN_XFER_BLK/USB_MAX_XFER_BLK trasfer blocks that should be checked for success starting from minimum to maximum, and rest of the read/write are performed with that optimal value. It tries to increase/ decrease the blocks in follwing scenarios:

1.decrease blocks: when read/write for a particular number of blocks fails.
2. increase blocks: when read/write for a particular number of blocks pass and amount left to trasfer is greater than current number of blocks.

Currently changes are done for EHCI where min = 4096 and max = 65535 is taken. And for other cases code is left unchanged by keeping min = max = 20.

Signed-off-by Sriram Dash <[email protected]>

Signed-off-by Rajesh Bhagat <[email protected]>

---
 common/usb_storage.c | 71 +++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 59 insertions(+), 12 deletions(-)

common/usb_storage.c +59 ~~-12~~

index 7e6e52d..eee8f4c 100644
@@ -106,10 +106,13 @@ struct us_data {
  * enough free heap space left, but the SCSI READ(10) and WRITE(10) commands are
  * limited to 65535 blocks.
  */
+#define USB_MIN_XFER_BLK	4095
 #define USB_MAX_XFER_BLK	65535
 #else
+#define USB_MIN_XFER_BLK	20
 #define USB_MAX_XFER_BLK	20
 #endif
+#define USB_CUR_XFER_BLK(n)	(n >= 0 ? ((1 << (12 + (n))) - 1) : 0)
 
 #ifndef CONFIG_BLK
 static struct us_data usb_stor[USB_MAX_STOR_DEV];

@@ -1117,11 +1120,13 @@ static unsigned long usb_stor_read(struct blk_desc *block_dev, lbaint_t blknr,
 	unsigned short smallblks;
 	struct usb_device *udev;
 	struct us_data *ss;
-	int retry;
+	int retry, pos = 0;
+	bool retry_flag = false;
 	ccb *srb = &usb_ccb;
 #ifdef CONFIG_BLK
 	struct blk_desc *block_dev;
 #endif
+	unsigned short usb_cur_xfer_blk = USB_CUR_XFER_BLK(pos);
 
 	if (blkcnt == 0)
 		return 0;

@@ -1153,26 +1158,46 @@ static unsigned long usb_stor_read(struct blk_desc *block_dev, lbaint_t blknr,
 		/* XXX need some comment here */
 		retry = 2;
 		srb->pdata = (unsigned char *)buf_addr;
-		if (blks > USB_MAX_XFER_BLK)
-			smallblks = USB_MAX_XFER_BLK;
+		if (blks > usb_cur_xfer_blk)
+			smallblks = usb_cur_xfer_blk;
 		else
 			smallblks = (unsigned short) blks;
 retry_it:
-		if (smallblks == USB_MAX_XFER_BLK)
+		debug("usb_read: retry #%d, usb_cur_xfer_blk %hu, smallblks %hu\n",
+		      retry, usb_cur_xfer_blk, smallblks);
+		if (smallblks == usb_cur_xfer_blk)
 			usb_show_progress();
 		srb->datalen = block_dev->blksz * smallblks;
 		srb->pdata = (unsigned char *)buf_addr;
 		if (usb_read_10(srb, ss, start, smallblks)) {
 			debug("Read ERROR\n");
 			usb_request_sense(srb, ss);
-			if (retry--)
+			if (retry--) {
+				/* decrease the usb_cur_xfer_blk */
+				unsigned short size = USB_CUR_XFER_BLK(pos - 1);
+				if (size >= USB_MIN_XFER_BLK) {
+					smallblks = size;
+					usb_cur_xfer_blk = smallblks;
+					pos--;
+				}
+				retry_flag = true;
 				goto retry_it;
+			}
 			blkcnt -= blks;
 			break;
 		}
 		start += smallblks;
 		blks -= smallblks;
 		buf_addr += srb->datalen;
+
+		/* try to increase the usb_cur_xfer_blk */
+		if (!retry_flag) {
+			unsigned short size = USB_CUR_XFER_BLK(pos + 1);
+			if (size <= blks && size <= USB_MAX_XFER_BLK) {
+				usb_cur_xfer_blk = size;
+				pos++;
+			}
+		}
 	} while (blks != 0);
 	ss->flags &= ~USB_READY;

@@ -1181,7 +1206,7 @@ retry_it:
 	      start, smallblks, buf_addr);
 
 	usb_disable_asynch(0); /* asynch transfer allowed */
-	if (blkcnt >= USB_MAX_XFER_BLK)
+	if (blkcnt >= usb_cur_xfer_blk)
 		debug("\n");
 	return blkcnt;
 }

@@ -1199,11 +1224,13 @@ static unsigned long usb_stor_write(struct blk_desc *block_dev, lbaint_t blknr,
 	unsigned short smallblks;
 	struct usb_device *udev;
 	struct us_data *ss;
-	int retry;
+	int retry, pos = 0;
+	bool retry_flag = false;
 	ccb *srb = &usb_ccb;
 #ifdef CONFIG_BLK
 	struct blk_desc *block_dev;
 #endif
+	unsigned short usb_cur_xfer_blk = USB_CUR_XFER_BLK(pos);
 
 	if (blkcnt == 0)
 		return 0;

@@ -1239,26 +1266,46 @@ static unsigned long usb_stor_write(struct blk_desc *block_dev, lbaint_t blknr,
 		 */
 		retry = 2;
 		srb->pdata = (unsigned char *)buf_addr;
-		if (blks > USB_MAX_XFER_BLK)
-			smallblks = USB_MAX_XFER_BLK;
+		if (blks > usb_cur_xfer_blk)
+			smallblks = usb_cur_xfer_blk;
 		else
 			smallblks = (unsigned short) blks;
 retry_it:
-		if (smallblks == USB_MAX_XFER_BLK)
+		debug("usb_write: retry #%d, usb_cur_xfer_blk %hu, smallblks %hu\n",
+		      retry, usb_cur_xfer_blk, smallblks);
+		if (smallblks == usb_cur_xfer_blk)
 			usb_show_progress();
 		srb->datalen = block_dev->blksz * smallblks;
 		srb->pdata = (unsigned char *)buf_addr;
 		if (usb_write_10(srb, ss, start, smallblks)) {
 			debug("Write ERROR\n");
 			usb_request_sense(srb, ss);
-			if (retry--)
+			if (retry--) {
+				/* decrease the usb_cur_xfer_blk */
+				unsigned short size = USB_CUR_XFER_BLK(pos - 1);
+				if (size >= USB_MIN_XFER_BLK) {
+					smallblks = size;
+					usb_cur_xfer_blk = smallblks;
+					pos--;
+				}
+				retry_flag = true;
 				goto retry_it;
+			}
 			blkcnt -= blks;
 			break;
 		}
 		start += smallblks;
 		blks -= smallblks;
 		buf_addr += srb->datalen;
+
+		/* try to increase the usb_cur_xfer_blk */
+		if (!retry_flag) {
+			unsigned short size = USB_CUR_XFER_BLK(pos + 1);
+			if (size <= blks && size <= USB_MAX_XFER_BLK) {
+				usb_cur_xfer_blk = size;
+				pos++;
+			}
+		}
 	} while (blks != 0);
 	ss->flags &= ~USB_READY;

@@ -1266,7 +1313,7 @@ retry_it:
 	      PRIxPTR "\n", start, smallblks, buf_addr);
 
 	usb_disable_asynch(0); /* asynch transfer allowed */
-	if (blkcnt >= USB_MAX_XFER_BLK)
+	if (blkcnt >= usb_cur_xfer_blk)
 		debug("\n");
 	return blkcnt;

Signature · 1 line

2.6.2.198.g614a2ac

Marek Vasut

2016-06-03 22:51 UTC #1 lore raw

PATCH v2 1/1 common: usb_storage : Implement logic to calculate optimal usb maximum trasfer blocks

Quoted 30 lines · Rajesh Bhagat

Implements the logic to calculate the optimal usb maximum trasfer blocks instead of sending USB_MAX_XFER_BLK blocks which is 65535 and 20 in case of EHCI and other USB protocols respectively.
It defines USB_MIN_XFER_BLK/USB_MAX_XFER_BLK trasfer blocks that should be checked for success starting from minimum to maximum, and rest of the read/write are performed with that optimal value. It tries to increase/ decrease the blocks in follwing scenarios:
1.decrease blocks: when read/write for a particular number of blocks fails.
2. increase blocks: when read/write for a particular number of blocks pass and amount left to trasfer is greater than current number of blocks.
Currently changes are done for EHCI where min = 4096 and max = 65535 is taken. And for other cases code is left unchanged by keeping min = max = 20.
Signed-off-by Sriram Dash <[email protected]>
Signed-off-by Rajesh Bhagat <[email protected]>
---
 common/usb_storage.c | 71 +++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 59 insertions(+), 12 deletions(-)
common/usb_storage.c +0 -0
index 7e6e52d..eee8f4c 100644

common/usb_storage.c struct us_data { · line 115

Quoted 10 lines

common/usb_storage.c +3 -0

@@ -106,10 +106,13 @@ struct us_data {
  * enough free heap space left, but the SCSI READ(10) and WRITE(10) commands are
  * limited to 65535 blocks.
  */
+#define USB_MIN_XFER_BLK	4095
 #define USB_MAX_XFER_BLK	65535
 #else
+#define USB_MIN_XFER_BLK	20
 #define USB_MAX_XFER_BLK	20
 #endif
+#define USB_CUR_XFER_BLK(n)	(n >= 0 ? ((1 << (12 + (n))) - 1) : 0)

Can this be ever called with n < 0 ? You should make this into a function to get typechecking on it too.

Quoted 4 lines

common/usb_storage.c +0 -0

 #ifndef CONFIG_BLK
 static struct us_data usb_stor[USB_MAX_STOR_DEV];

@@ -1117,11 +1120,13 @@ static unsigned long usb_stor_read(struct blk_desc *block_dev, lbaint_t blknr,
 	unsigned short smallblks;

common/usb_storage.c static unsigned long usb_stor_read(struct blk_desc *block_dev, lbaint_t blknr, · line 1129

Quoted 10 lines

common/usb_storage.c +3 -1

 	struct usb_device *udev;
 	struct us_data *ss;
-	int retry;
+	int retry, pos = 0;
+	bool retry_flag = false;
 	ccb *srb = &usb_ccb;
 #ifdef CONFIG_BLK
 	struct blk_desc *block_dev;
 #endif
+	unsigned short usb_cur_xfer_blk = USB_CUR_XFER_BLK(pos);

How will this behave if you keep alternating between two block_dev devices ? It will always start looking for the best possible transfer length from scratch, right ? That's not great ...

Quoted 24 lines

common/usb_storage.c +5 -4

 	if (blkcnt == 0)
 		return 0;

@@ -1153,26 +1158,46 @@ static unsigned long usb_stor_read(struct blk_desc *block_dev, lbaint_t blknr,
 		/* XXX need some comment here */
 		retry = 2;
 		srb->pdata = (unsigned char *)buf_addr;
-		if (blks > USB_MAX_XFER_BLK)
-			smallblks = USB_MAX_XFER_BLK;
+		if (blks > usb_cur_xfer_blk)
+			smallblks = usb_cur_xfer_blk;
 		else
 			smallblks = (unsigned short) blks;
 retry_it:
-		if (smallblks == USB_MAX_XFER_BLK)
+		debug("usb_read: retry #%d, usb_cur_xfer_blk %hu, smallblks %hu\n",
+		      retry, usb_cur_xfer_blk, smallblks);
+		if (smallblks == usb_cur_xfer_blk)
 			usb_show_progress();
 		srb->datalen = block_dev->blksz * smallblks;
 		srb->pdata = (unsigned char *)buf_addr;
 		if (usb_read_10(srb, ss, start, smallblks)) {
 			debug("Read ERROR\n");
 			usb_request_sense(srb, ss);
-			if (retry--)

common/usb_storage.c static unsigned long usb_stor_read(struct blk_desc *block_dev, lbaint_t blknr, · line 1184

Quoted 10 lines

common/usb_storage.c +9 -0

+			if (retry--) {
+				/* decrease the usb_cur_xfer_blk */
+				unsigned short size = USB_CUR_XFER_BLK(pos - 1);
+				if (size >= USB_MIN_XFER_BLK) {
+					smallblks = size;
+					usb_cur_xfer_blk = smallblks;
+					pos--;
+				}
+				retry_flag = true;
 				goto retry_it;

What is the reason for having the same code twice in this patch ? Just pull the identical stuff into a function.

Quoted 104 lines

common/usb_storage.c +39 -7

+			}
 			blkcnt -= blks;
 			break;
 		}
 		start += smallblks;
 		blks -= smallblks;
 		buf_addr += srb->datalen;
+
+		/* try to increase the usb_cur_xfer_blk */
+		if (!retry_flag) {
+			unsigned short size = USB_CUR_XFER_BLK(pos + 1);
+			if (size <= blks && size <= USB_MAX_XFER_BLK) {
+				usb_cur_xfer_blk = size;
+				pos++;
+			}
+		}
 	} while (blks != 0);
 	ss->flags &= ~USB_READY;

@@ -1181,7 +1206,7 @@ retry_it:
 	      start, smallblks, buf_addr);
 
 	usb_disable_asynch(0); /* asynch transfer allowed */
-	if (blkcnt >= USB_MAX_XFER_BLK)
+	if (blkcnt >= usb_cur_xfer_blk)
 		debug("\n");
 	return blkcnt;
 }

@@ -1199,11 +1224,13 @@ static unsigned long usb_stor_write(struct blk_desc *block_dev, lbaint_t blknr,
 	unsigned short smallblks;
 	struct usb_device *udev;
 	struct us_data *ss;
-	int retry;
+	int retry, pos = 0;
+	bool retry_flag = false;
 	ccb *srb = &usb_ccb;
 #ifdef CONFIG_BLK
 	struct blk_desc *block_dev;
 #endif
+	unsigned short usb_cur_xfer_blk = USB_CUR_XFER_BLK(pos);
 
 	if (blkcnt == 0)
 		return 0;

@@ -1239,26 +1266,46 @@ static unsigned long usb_stor_write(struct blk_desc *block_dev, lbaint_t blknr,
 		 */
 		retry = 2;
 		srb->pdata = (unsigned char *)buf_addr;
-		if (blks > USB_MAX_XFER_BLK)
-			smallblks = USB_MAX_XFER_BLK;
+		if (blks > usb_cur_xfer_blk)
+			smallblks = usb_cur_xfer_blk;
 		else
 			smallblks = (unsigned short) blks;
 retry_it:
-		if (smallblks == USB_MAX_XFER_BLK)
+		debug("usb_write: retry #%d, usb_cur_xfer_blk %hu, smallblks %hu\n",
+		      retry, usb_cur_xfer_blk, smallblks);
+		if (smallblks == usb_cur_xfer_blk)
 			usb_show_progress();
 		srb->datalen = block_dev->blksz * smallblks;
 		srb->pdata = (unsigned char *)buf_addr;
 		if (usb_write_10(srb, ss, start, smallblks)) {
 			debug("Write ERROR\n");
 			usb_request_sense(srb, ss);
-			if (retry--)
+			if (retry--) {
+				/* decrease the usb_cur_xfer_blk */
+				unsigned short size = USB_CUR_XFER_BLK(pos - 1);
+				if (size >= USB_MIN_XFER_BLK) {
+					smallblks = size;
+					usb_cur_xfer_blk = smallblks;
+					pos--;
+				}
+				retry_flag = true;
 				goto retry_it;
+			}
 			blkcnt -= blks;
 			break;
 		}
 		start += smallblks;
 		blks -= smallblks;
 		buf_addr += srb->datalen;
+
+		/* try to increase the usb_cur_xfer_blk */
+		if (!retry_flag) {
+			unsigned short size = USB_CUR_XFER_BLK(pos + 1);
+			if (size <= blks && size <= USB_MAX_XFER_BLK) {
+				usb_cur_xfer_blk = size;
+				pos++;
+			}
+		}
 	} while (blks != 0);
 	ss->flags &= ~USB_READY;

@@ -1266,7 +1313,7 @@ retry_it:
 	      PRIxPTR "\n", start, smallblks, buf_addr);
 
 	usb_disable_asynch(0); /* asynch transfer allowed */
-	if (blkcnt >= USB_MAX_XFER_BLK)
+	if (blkcnt >= usb_cur_xfer_blk)
 		debug("\n");
 	return blkcnt;

Signature · 2 lines

Best regards,
Marek Vasut

Rajesh Bhagat

author

2016-06-06 04:19 UTC #2 lore raw

PATCH v2 1/1 common: usb_storage : Implement logic to calculate optimal usb maximum trasfer blocks

Quoted 45 lines

-----Original Message-----
From: Marek Vasut [mailto:marex at denx.de]
Sent: Saturday, June 04, 2016 4:22 AM
To: Rajesh Bhagat <[email protected]>; u-boot at lists.denx.de
Cc: sjg at chromium.org; york sun <[email protected]>; Sriram Dash <[email protected]>
Subject: Re: [PATCH v2] common: usb_storage : Implement logic to calculate optimal usb maximum trasfer blocks
Quoted 31 lines · Rajesh Bhagat
Implements the logic to calculate the optimal usb maximum trasfer blocks instead of sending USB_MAX_XFER_BLK blocks which is 65535 and 20 in case of EHCI and other USB protocols respectively.
It defines USB_MIN_XFER_BLK/USB_MAX_XFER_BLK trasfer blocks that should be checked for success starting from minimum to maximum, and rest of the read/write are performed with that optimal value. It tries to increase/ decrease the blocks in follwing scenarios:
1.decrease blocks: when read/write for a particular number of blocks fails.
2. increase blocks: when read/write for a particular number of blocks pass and amount left to trasfer is greater than current number of blocks.
Currently changes are done for EHCI where min = 4096 and max = 65535 is taken. And for other cases code is left unchanged by keeping min = max = 20.
Signed-off-by Sriram Dash <[email protected]>
Signed-off-by Rajesh Bhagat <[email protected]>
---
 common/usb_storage.c | 71
+++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 59 insertions(+), 12 deletions(-)
common/usb_storage.c index renamed from common/usb_storage.c +0 -0
7e6e52d..eee8f4c 100644
common/usb_storage.c struct us_data { · line 106
Quoted 1 line
common/usb_storage.c +0 -0
@@ -106,10 +106,13 @@ struct us_data {
  * enough free heap space left, but the SCSI READ(10) and WRITE(10) commands
are

Quoted 10 lines

common/usb_storage.c struct us_data { · line 115

Quoted 9 lines

common/usb_storage.c +3 -0

  * limited to 65535 blocks.
  */
+#define USB_MIN_XFER_BLK	4095
 #define USB_MAX_XFER_BLK	65535
 #else
+#define USB_MIN_XFER_BLK	20
 #define USB_MAX_XFER_BLK	20
 #endif
+#define USB_CUR_XFER_BLK(n)	(n >= 0 ? ((1 << (12 + (n))) - 1) : 0)

Hello Marek,

Quoted 3 lines

Can this be ever called with n < 0 ? You should make this into a function to get typechecking on it too.

Yes. When transfer fails for the first time (pos - 1) is passed to this macro. Ok, I will convert it to a function in v3.

Quoted 4 lines

common/usb_storage.c struct us_data { · line 118
Quoted 3 lines
common/usb_storage.c +1 -0
 #ifndef CONFIG_BLK
 static struct us_data usb_stor[USB_MAX_STOR_DEV]; @@ -1117,11
+1120,13 @@ static unsigned long usb_stor_read(struct blk_desc *block_dev,
lbaint_t blknr,

Quoted 15 lines

common/usb_storage.c static unsigned long usb_stor_read(struct blk_desc *block_dev, lbaint_t blknr, · line 1129
Quoted 11 lines
common/usb_storage.c +3 -1
 	unsigned short smallblks;
 	struct usb_device *udev;
 	struct us_data *ss;
-	int retry;
+	int retry, pos = 0;
+	bool retry_flag = false;
 	ccb *srb = &usb_ccb;
 #ifdef CONFIG_BLK
 	struct blk_desc *block_dev;
 #endif
+	unsigned short usb_cur_xfer_blk = USB_CUR_XFER_BLK(pos);
How will this behave if you keep alternating between two block_dev devices ? It will always start looking for the best possible transfer length from scratch, right ? That's not great ...

How about adding a field name "cur_xfer_blks" in struct usb_device and updating it on device basis , it will help retain the value.

struct usb_device {
...

        unsigned short cur_xfer_blks;
};

Quoted 31 lines

common/usb_storage.c static unsigned long usb_stor_read(struct blk_desc

Quoted 4 lines

common/usb_storage.c +0 -0

 	if (blkcnt == 0)
 		return 0;

@@ -1153,26 +1158,46 @@ static unsigned long usb_stor_read(struct blk_desc

*block_dev, lbaint_t blknr,

Quoted 26 lines

common/usb_storage.c +10 -4

 		/* XXX need some comment here */
 		retry = 2;
 		srb->pdata = (unsigned char *)buf_addr;
-		if (blks > USB_MAX_XFER_BLK)
-			smallblks = USB_MAX_XFER_BLK;
+		if (blks > usb_cur_xfer_blk)
+			smallblks = usb_cur_xfer_blk;
 		else
 			smallblks = (unsigned short) blks;
 retry_it:
-		if (smallblks == USB_MAX_XFER_BLK)
+		debug("usb_read: retry #%d, usb_cur_xfer_blk %hu, smallblks %hu\n",
+		      retry, usb_cur_xfer_blk, smallblks);
+		if (smallblks == usb_cur_xfer_blk)
 			usb_show_progress();
 		srb->datalen = block_dev->blksz * smallblks;
 		srb->pdata = (unsigned char *)buf_addr;
 		if (usb_read_10(srb, ss, start, smallblks)) {
 			debug("Read ERROR\n");
 			usb_request_sense(srb, ss);
-			if (retry--)
+			if (retry--) {
+				/* decrease the usb_cur_xfer_blk */
+				unsigned short size = USB_CUR_XFER_BLK(pos - 1);
+				if (size >= USB_MIN_XFER_BLK) {
+					smallblks = size;

Quoted 9 lines

common/usb_storage.c static unsigned long usb_stor_read(struct blk_desc *block_dev, lbaint_t blknr, · line 1184
Quoted 5 lines
common/usb_storage.c +4 -0
+					usb_cur_xfer_blk = smallblks;
+					pos--;
+				}
+				retry_flag = true;
 				goto retry_it;
What is the reason for having the same code twice in this patch ? Just pull the identical stuff into a function.

Ok, I will add above code in function namely dec_cur_xfer_blks/ inc_cur_xfer_blks in v3.

Best Regards,
Rajesh Bhagat

Quoted 111 lines

common/usb_storage.c static unsigned long usb_stor_write(struct blk_desc

Quoted 29 lines

common/usb_storage.c +11 -1

+			}
 			blkcnt -= blks;
 			break;
 		}
 		start += smallblks;
 		blks -= smallblks;
 		buf_addr += srb->datalen;
+
+		/* try to increase the usb_cur_xfer_blk */
+		if (!retry_flag) {
+			unsigned short size = USB_CUR_XFER_BLK(pos + 1);
+			if (size <= blks && size <= USB_MAX_XFER_BLK) {
+				usb_cur_xfer_blk = size;
+				pos++;
+			}
+		}
 	} while (blks != 0);
 	ss->flags &= ~USB_READY;

@@ -1181,7 +1206,7 @@ retry_it:
 	      start, smallblks, buf_addr);
 
 	usb_disable_asynch(0); /* asynch transfer allowed */
-	if (blkcnt >= USB_MAX_XFER_BLK)
+	if (blkcnt >= usb_cur_xfer_blk)
 		debug("\n");
 	return blkcnt;
 }

@@ -1199,11 +1224,13 @@ static unsigned long usb_stor_write(struct blk_desc

*block_dev, lbaint_t blknr,

common/usb_storage.c static unsigned long usb_stor_write(struct blk_desc

Quoted 15 lines

common/usb_storage.c +3 -1

 	unsigned short smallblks;
 	struct usb_device *udev;
 	struct us_data *ss;
-	int retry;
+	int retry, pos = 0;
+	bool retry_flag = false;
 	ccb *srb = &usb_ccb;
 #ifdef CONFIG_BLK
 	struct blk_desc *block_dev;
 #endif
+	unsigned short usb_cur_xfer_blk = USB_CUR_XFER_BLK(pos);
 
 	if (blkcnt == 0)
 		return 0;

@@ -1239,26 +1266,46 @@ static unsigned long usb_stor_write(struct blk_desc

*block_dev, lbaint_t blknr,

Quoted 52 lines

common/usb_storage.c +24 -4

 		 */
 		retry = 2;
 		srb->pdata = (unsigned char *)buf_addr;
-		if (blks > USB_MAX_XFER_BLK)
-			smallblks = USB_MAX_XFER_BLK;
+		if (blks > usb_cur_xfer_blk)
+			smallblks = usb_cur_xfer_blk;
 		else
 			smallblks = (unsigned short) blks;
 retry_it:
-		if (smallblks == USB_MAX_XFER_BLK)
+		debug("usb_write: retry #%d, usb_cur_xfer_blk %hu, smallblks %hu\n",
+		      retry, usb_cur_xfer_blk, smallblks);
+		if (smallblks == usb_cur_xfer_blk)
 			usb_show_progress();
 		srb->datalen = block_dev->blksz * smallblks;
 		srb->pdata = (unsigned char *)buf_addr;
 		if (usb_write_10(srb, ss, start, smallblks)) {
 			debug("Write ERROR\n");
 			usb_request_sense(srb, ss);
-			if (retry--)
+			if (retry--) {
+				/* decrease the usb_cur_xfer_blk */
+				unsigned short size = USB_CUR_XFER_BLK(pos - 1);
+				if (size >= USB_MIN_XFER_BLK) {
+					smallblks = size;
+					usb_cur_xfer_blk = smallblks;
+					pos--;
+				}
+				retry_flag = true;
 				goto retry_it;
+			}
 			blkcnt -= blks;
 			break;
 		}
 		start += smallblks;
 		blks -= smallblks;
 		buf_addr += srb->datalen;
+
+		/* try to increase the usb_cur_xfer_blk */
+		if (!retry_flag) {
+			unsigned short size = USB_CUR_XFER_BLK(pos + 1);
+			if (size <= blks && size <= USB_MAX_XFER_BLK) {
+				usb_cur_xfer_blk = size;
+				pos++;
+			}
+		}
 	} while (blks != 0);
 	ss->flags &= ~USB_READY;

common/usb_storage.c retry_it: · line 1319

Quoted 8 lines

common/usb_storage.c +1 -1

@@ -1266,7 +1313,7 @@ retry_it:
 	      PRIxPTR "\n", start, smallblks, buf_addr);
 
 	usb_disable_asynch(0); /* asynch transfer allowed */
-	if (blkcnt >= USB_MAX_XFER_BLK)
+	if (blkcnt >= usb_cur_xfer_blk)
 		debug("\n");
 	return blkcnt;

--
Best regards,
Marek Vasut

Marek Vasut

2016-06-06 13:19 UTC #3 lore raw

PATCH v2 1/1 common: usb_storage : Implement logic to calculate optimal usb maximum trasfer blocks

Quoted 56 lines · Rajesh Bhagat

Quoted 45 lines
-----Original Message-----
From: Marek Vasut [mailto:marex at denx.de]
Sent: Saturday, June 04, 2016 4:22 AM
To: Rajesh Bhagat <[email protected]>; u-boot at lists.denx.de
Cc: sjg at chromium.org; york sun <[email protected]>; Sriram Dash <[email protected]>
Subject: Re: [PATCH v2] common: usb_storage : Implement logic to calculate optimal usb maximum trasfer blocks
Quoted 31 lines · Rajesh Bhagat
Implements the logic to calculate the optimal usb maximum trasfer blocks instead of sending USB_MAX_XFER_BLK blocks which is 65535 and 20 in case of EHCI and other USB protocols respectively.
It defines USB_MIN_XFER_BLK/USB_MAX_XFER_BLK trasfer blocks that should be checked for success starting from minimum to maximum, and rest of the read/write are performed with that optimal value. It tries to increase/ decrease the blocks in follwing scenarios:
1.decrease blocks: when read/write for a particular number of blocks fails.
2. increase blocks: when read/write for a particular number of blocks pass and amount left to trasfer is greater than current number of blocks.
Currently changes are done for EHCI where min = 4096 and max = 65535 is taken. And for other cases code is left unchanged by keeping min = max = 20.
Signed-off-by Sriram Dash <[email protected]>
Signed-off-by Rajesh Bhagat <[email protected]>
---
 common/usb_storage.c | 71
+++++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 59 insertions(+), 12 deletions(-)
common/usb_storage.c index renamed from common/usb_storage.c +0 -0
7e6e52d..eee8f4c 100644
common/usb_storage.c struct us_data { · line 106
Quoted 1 line
common/usb_storage.c +0 -0
@@ -106,10 +106,13 @@ struct us_data {
  * enough free heap space left, but the SCSI READ(10) and WRITE(10) commands
are
Quoted 10 lines
common/usb_storage.c struct us_data { · line 115
Quoted 9 lines
common/usb_storage.c +3 -0
  * limited to 65535 blocks.
  */
+#define USB_MIN_XFER_BLK	4095
 #define USB_MAX_XFER_BLK	65535
 #else
+#define USB_MIN_XFER_BLK	20
 #define USB_MAX_XFER_BLK	20
 #endif
+#define USB_CUR_XFER_BLK(n)	(n >= 0 ? ((1 << (12 + (n))) - 1) : 0)

Quoted 8 lines

Hello Marek,
Quoted 3 lines
Can this be ever called with n < 0 ? You should make this into a function to get typechecking on it too.
Yes. When transfer fails for the first time (pos - 1) is passed to this macro. Ok, I will convert it to a function in v3.

This should be handled outside of the macro then.

Quoted 20 lines

Quoted 4 lines
common/usb_storage.c struct us_data { · line 118
Quoted 3 lines
common/usb_storage.c +1 -0
 #ifndef CONFIG_BLK
 static struct us_data usb_stor[USB_MAX_STOR_DEV]; @@ -1117,11
+1120,13 @@ static unsigned long usb_stor_read(struct blk_desc *block_dev,
lbaint_t blknr,
Quoted 15 lines
common/usb_storage.c static unsigned long usb_stor_read(struct blk_desc *block_dev, lbaint_t blknr, · line 1129
Quoted 11 lines
common/usb_storage.c +3 -1
 	unsigned short smallblks;
 	struct usb_device *udev;
 	struct us_data *ss;
-	int retry;
+	int retry, pos = 0;
+	bool retry_flag = false;
 	ccb *srb = &usb_ccb;
 #ifdef CONFIG_BLK
 	struct blk_desc *block_dev;
 #endif
+	unsigned short usb_cur_xfer_blk = USB_CUR_XFER_BLK(pos);
How will this behave if you keep alternating between two block_dev devices ? It will always start looking for the best possible transfer length from scratch, right ? That's not great ...

Quoted 2 lines

How about adding a field name "cur_xfer_blks" in struct usb_device and updating it on device basis , it will help retain the value.

That might work, yes.

Quoted 162 lines

struct usb_device {
...

        unsigned short cur_xfer_blks;
};

Quoted 31 lines

common/usb_storage.c static unsigned long usb_stor_read(struct blk_desc

Quoted 4 lines

common/usb_storage.c +0 -0

 	if (blkcnt == 0)
 		return 0;

@@ -1153,26 +1158,46 @@ static unsigned long usb_stor_read(struct blk_desc

*block_dev, lbaint_t blknr,

Quoted 26 lines

common/usb_storage.c +10 -4

 		/* XXX need some comment here */
 		retry = 2;
 		srb->pdata = (unsigned char *)buf_addr;
-		if (blks > USB_MAX_XFER_BLK)
-			smallblks = USB_MAX_XFER_BLK;
+		if (blks > usb_cur_xfer_blk)
+			smallblks = usb_cur_xfer_blk;
 		else
 			smallblks = (unsigned short) blks;
 retry_it:
-		if (smallblks == USB_MAX_XFER_BLK)
+		debug("usb_read: retry #%d, usb_cur_xfer_blk %hu, smallblks %hu\n",
+		      retry, usb_cur_xfer_blk, smallblks);
+		if (smallblks == usb_cur_xfer_blk)
 			usb_show_progress();
 		srb->datalen = block_dev->blksz * smallblks;
 		srb->pdata = (unsigned char *)buf_addr;
 		if (usb_read_10(srb, ss, start, smallblks)) {
 			debug("Read ERROR\n");
 			usb_request_sense(srb, ss);
-			if (retry--)
+			if (retry--) {
+				/* decrease the usb_cur_xfer_blk */
+				unsigned short size = USB_CUR_XFER_BLK(pos - 1);
+				if (size >= USB_MIN_XFER_BLK) {
+					smallblks = size;

Quoted 9 lines

common/usb_storage.c static unsigned long usb_stor_read(struct blk_desc *block_dev, lbaint_t blknr, · line 1184
Quoted 5 lines
common/usb_storage.c +4 -0
+					usb_cur_xfer_blk = smallblks;
+					pos--;
+				}
+				retry_flag = true;
 				goto retry_it;
What is the reason for having the same code twice in this patch ? Just pull the identical stuff into a function.

Ok, I will add above code in function namely dec_cur_xfer_blks/ inc_cur_xfer_blks in v3.

Best Regards,
Rajesh Bhagat

Quoted 111 lines

common/usb_storage.c static unsigned long usb_stor_write(struct blk_desc

Quoted 29 lines

common/usb_storage.c +11 -1

+			}
 			blkcnt -= blks;
 			break;
 		}
 		start += smallblks;
 		blks -= smallblks;
 		buf_addr += srb->datalen;
+
+		/* try to increase the usb_cur_xfer_blk */
+		if (!retry_flag) {
+			unsigned short size = USB_CUR_XFER_BLK(pos + 1);
+			if (size <= blks && size <= USB_MAX_XFER_BLK) {
+				usb_cur_xfer_blk = size;
+				pos++;
+			}
+		}
 	} while (blks != 0);
 	ss->flags &= ~USB_READY;

@@ -1181,7 +1206,7 @@ retry_it:
 	      start, smallblks, buf_addr);
 
 	usb_disable_asynch(0); /* asynch transfer allowed */
-	if (blkcnt >= USB_MAX_XFER_BLK)
+	if (blkcnt >= usb_cur_xfer_blk)
 		debug("\n");
 	return blkcnt;
 }

@@ -1199,11 +1224,13 @@ static unsigned long usb_stor_write(struct blk_desc

*block_dev, lbaint_t blknr,

common/usb_storage.c static unsigned long usb_stor_write(struct blk_desc

Quoted 15 lines

common/usb_storage.c +3 -1

 	unsigned short smallblks;
 	struct usb_device *udev;
 	struct us_data *ss;
-	int retry;
+	int retry, pos = 0;
+	bool retry_flag = false;
 	ccb *srb = &usb_ccb;
 #ifdef CONFIG_BLK
 	struct blk_desc *block_dev;
 #endif
+	unsigned short usb_cur_xfer_blk = USB_CUR_XFER_BLK(pos);
 
 	if (blkcnt == 0)
 		return 0;

@@ -1239,26 +1266,46 @@ static unsigned long usb_stor_write(struct blk_desc

*block_dev, lbaint_t blknr,

Quoted 52 lines

common/usb_storage.c +24 -4

 		 */
 		retry = 2;
 		srb->pdata = (unsigned char *)buf_addr;
-		if (blks > USB_MAX_XFER_BLK)
-			smallblks = USB_MAX_XFER_BLK;
+		if (blks > usb_cur_xfer_blk)
+			smallblks = usb_cur_xfer_blk;
 		else
 			smallblks = (unsigned short) blks;
 retry_it:
-		if (smallblks == USB_MAX_XFER_BLK)
+		debug("usb_write: retry #%d, usb_cur_xfer_blk %hu, smallblks %hu\n",
+		      retry, usb_cur_xfer_blk, smallblks);
+		if (smallblks == usb_cur_xfer_blk)
 			usb_show_progress();
 		srb->datalen = block_dev->blksz * smallblks;
 		srb->pdata = (unsigned char *)buf_addr;
 		if (usb_write_10(srb, ss, start, smallblks)) {
 			debug("Write ERROR\n");
 			usb_request_sense(srb, ss);
-			if (retry--)
+			if (retry--) {
+				/* decrease the usb_cur_xfer_blk */
+				unsigned short size = USB_CUR_XFER_BLK(pos - 1);
+				if (size >= USB_MIN_XFER_BLK) {
+					smallblks = size;
+					usb_cur_xfer_blk = smallblks;
+					pos--;
+				}
+				retry_flag = true;
 				goto retry_it;
+			}
 			blkcnt -= blks;
 			break;
 		}
 		start += smallblks;
 		blks -= smallblks;
 		buf_addr += srb->datalen;
+
+		/* try to increase the usb_cur_xfer_blk */
+		if (!retry_flag) {
+			unsigned short size = USB_CUR_XFER_BLK(pos + 1);
+			if (size <= blks && size <= USB_MAX_XFER_BLK) {
+				usb_cur_xfer_blk = size;
+				pos++;
+			}
+		}
 	} while (blks != 0);
 	ss->flags &= ~USB_READY;

common/usb_storage.c retry_it: · line 1319

Quoted 8 lines

common/usb_storage.c +1 -1

@@ -1266,7 +1313,7 @@ retry_it:
 	      PRIxPTR "\n", start, smallblks, buf_addr);
 
 	usb_disable_asynch(0); /* asynch transfer allowed */
-	if (blkcnt >= USB_MAX_XFER_BLK)
+	if (blkcnt >= usb_cur_xfer_blk)
 		debug("\n");
 	return blkcnt;

--
Best regards,
Marek Vasut

Signature · 2 lines

Best regards,
Marek Vasut