[U-Boot] [PATCH v3] common: usb_storage : Implement logic to calculate optimal usb maximum trasfer blocks
Rajesh Bhagat
rajesh.bhagat at nxp.com
Tue Jun 7 11:29:51 CEST 2016
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 <sriram.dash at nxp.com>
Signed-off-by: Rajesh Bhagat <rajesh.bhagat at nxp.com>
---
Changes in v3:
- Adds cur_xfer_blks in struct usb_device to retain values
- Adds functions dec/inc_cur_xfer_blks to remove code duplication
- Moves check from macro to calling functions
Changes in v2:
- Removes table to store blocks and use formula (1 << (12 + n)) - 1
- Adds logic to start from minimum, go to maximum in each read/write
common/usb_storage.c | 78 ++++++++++++++++++++++++++++++++++++++++++++--------
include/usb.h | 1 +
2 files changed, 67 insertions(+), 12 deletions(-)
diff --git a/common/usb_storage.c b/common/usb_storage.c
index 7e6e52d..e08dcd4 100644
--- a/common/usb_storage.c
+++ b/common/usb_storage.c
@@ -106,11 +106,40 @@ 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 GET_CUR_XFER_BLKS(blks) (LOG2(blks / (USB_MIN_XFER_BLK + 1)))
+#define CALC_CUR_XFER_BLKS(pos) ((1 << (12 + pos)) - 1)
+
+static int dec_cur_xfer_blks(int *pos, unsigned short *smallblks)
+{
+ /* decrease the cur_xfer_blks */
+ unsigned short size = (*pos > 0) ? CALC_CUR_XFER_BLKS(*pos - 1) : 0;
+ if (size >= USB_MIN_XFER_BLK) {
+ *smallblks = size;
+ (*pos)--;
+ return 0;
+ }
+ return -EINVAL;
+}
+
+static int inc_cur_xfer_blks(int *pos, unsigned short *smallblks, lbaint_t blks)
+{
+ /* try to increase the cur_xfer_blks */
+ unsigned short size = (*pos >= 0) ? CALC_CUR_XFER_BLKS(*pos + 1) : 0;
+ if (size <= blks && size <= USB_MAX_XFER_BLK) {
+ *smallblks = size;
+ (*pos)++;
+ return 0;
+ }
+ return -EINVAL;
+}
+
#ifndef CONFIG_BLK
static struct us_data usb_stor[USB_MAX_STOR_DEV];
#endif
@@ -1117,7 +1146,8 @@ 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;
+ bool retry_flag = false;
ccb *srb = &usb_ccb;
#ifdef CONFIG_BLK
struct blk_desc *block_dev;
@@ -1145,6 +1175,7 @@ static unsigned long usb_stor_read(struct blk_desc *block_dev, lbaint_t blknr,
buf_addr = (uintptr_t)buffer;
start = blknr;
blks = blkcnt;
+ pos = GET_CUR_XFER_BLKS(udev->cur_xfer_blks);
debug("\nusb_read: dev %d startblk " LBAF ", blccnt " LBAF " buffer %"
PRIxPTR "\n", block_dev->devnum, start, blks, buf_addr);
@@ -1153,26 +1184,35 @@ 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 > udev->cur_xfer_blks)
+ smallblks = udev->cur_xfer_blks;
else
smallblks = (unsigned short) blks;
retry_it:
- if (smallblks == USB_MAX_XFER_BLK)
+ debug("usb_read: retry #%d, cur_xfer_blks %hu, smallblks %hu\n",
+ retry, udev->cur_xfer_blks, smallblks);
+ if (smallblks == udev->cur_xfer_blks)
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--) {
+ if (!dec_cur_xfer_blks(&pos, &smallblks))
+ udev->cur_xfer_blks = smallblks;
+ retry_flag = true;
goto retry_it;
+ }
blkcnt -= blks;
break;
}
start += smallblks;
blks -= smallblks;
buf_addr += srb->datalen;
+
+ if (!retry_flag && !inc_cur_xfer_blks(&pos, &smallblks, blks))
+ udev->cur_xfer_blks = smallblks;
} while (blks != 0);
ss->flags &= ~USB_READY;
@@ -1181,7 +1221,7 @@ retry_it:
start, smallblks, buf_addr);
usb_disable_asynch(0); /* asynch transfer allowed */
- if (blkcnt >= USB_MAX_XFER_BLK)
+ if (blkcnt >= udev->cur_xfer_blks)
debug("\n");
return blkcnt;
}
@@ -1199,7 +1239,8 @@ 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;
+ bool retry_flag = false;
ccb *srb = &usb_ccb;
#ifdef CONFIG_BLK
struct blk_desc *block_dev;
@@ -1222,6 +1263,7 @@ static unsigned long usb_stor_write(struct blk_desc *block_dev, lbaint_t blknr,
}
#endif
ss = (struct us_data *)udev->privptr;
+ pos = GET_CUR_XFER_BLKS(udev->cur_xfer_blks);
usb_disable_asynch(1); /* asynch transfer not allowed */
@@ -1239,26 +1281,35 @@ 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 > udev->cur_xfer_blks)
+ smallblks = udev->cur_xfer_blks;
else
smallblks = (unsigned short) blks;
retry_it:
- if (smallblks == USB_MAX_XFER_BLK)
+ debug("usb_write: retry #%d, cur_xfer_blks %hu, smallblks %hu\n",
+ retry, udev->cur_xfer_blks, smallblks);
+ if (smallblks == udev->cur_xfer_blks)
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--) {
+ if (!dec_cur_xfer_blks(&pos, &smallblks))
+ udev->cur_xfer_blks = smallblks;
+ retry_flag = true;
goto retry_it;
+ }
blkcnt -= blks;
break;
}
start += smallblks;
blks -= smallblks;
buf_addr += srb->datalen;
+
+ if (!retry_flag && !inc_cur_xfer_blks(&pos, &smallblks, blks))
+ udev->cur_xfer_blks = smallblks;
} while (blks != 0);
ss->flags &= ~USB_READY;
@@ -1266,7 +1317,7 @@ retry_it:
PRIxPTR "\n", start, smallblks, buf_addr);
usb_disable_asynch(0); /* asynch transfer allowed */
- if (blkcnt >= USB_MAX_XFER_BLK)
+ if (blkcnt >= udev->cur_xfer_blks)
debug("\n");
return blkcnt;
@@ -1331,6 +1382,9 @@ int usb_storage_probe(struct usb_device *dev, unsigned int ifnum,
break;
}
+ /* Initialize the current transfer blocks to minimum value */
+ dev->cur_xfer_blks = USB_MIN_XFER_BLK;
+
/*
* We are expecting a minimum of 2 endpoints - in and out (bulk).
* An optional interrupt is OK (necessary for CBI protocol).
diff --git a/include/usb.h b/include/usb.h
index 02a0ccd..bd49014 100644
--- a/include/usb.h
+++ b/include/usb.h
@@ -153,6 +153,7 @@ struct usb_device {
struct udevice *dev; /* Pointer to associated device */
struct udevice *controller_dev; /* Pointer to associated controller */
#endif
+ unsigned short cur_xfer_blks; /* Current maximum transfer blocks */
};
struct int_queue;
--
2.6.2.198.g614a2ac
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