From: Rajesh Bhagat rajesh.bhagat@freescale.com
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@nxp.com Signed-off-by: Rajesh Bhagat rajesh.bhagat@nxp.com --- Changes in v4: - Adds udev paramater in dec/inc_cur_xfer_blks function and adds sanity check on it. - Changes type of pos varible to unsigned int in dec/inc_cur_xfer_blks - Removes usage of pos varible from usb_stor_read/write
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 | 68 ++++++++++++++++++++++++++++++++++++++++++++++++---- include/usb.h | 1 + 2 files changed, 64 insertions(+), 5 deletions(-)
diff --git a/common/usb_storage.c b/common/usb_storage.c index 5efdc90..e109dfb 100644 --- a/common/usb_storage.c +++ b/common/usb_storage.c @@ -106,11 +106,16 @@ 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 + 1) / (USB_MIN_XFER_BLK + 1))) +#define CALC_CUR_XFER_BLKS(pos) ((1 << (12 + pos)) - 1) + #ifndef CONFIG_BLK static struct us_data usb_stor[USB_MAX_STOR_DEV]; #endif @@ -141,6 +146,44 @@ static void usb_show_progress(void) debug("."); }
+static int dec_cur_xfer_blks(struct usb_device *udev) +{ + /* decrease the cur_xfer_blks */ + unsigned int pos; + unsigned short size; + + if (!udev) + return -EINVAL; + + pos = GET_CUR_XFER_BLKS(udev->cur_xfer_blks); + size = pos ? CALC_CUR_XFER_BLKS(pos - 1) : 0; + + if (size < USB_MIN_XFER_BLK) + return -EINVAL; + + udev->cur_xfer_blks = size; + return 0; +} + +static int inc_cur_xfer_blks(struct usb_device *udev, lbaint_t blks) +{ + /* try to increase the cur_xfer_blks */ + unsigned int pos; + unsigned short size; + + if (!udev) + return -EINVAL; + + pos = GET_CUR_XFER_BLKS(udev->cur_xfer_blks); + size = CALC_CUR_XFER_BLKS(pos + 1); + + if (size > blks || size > USB_MAX_XFER_BLK) + return -EINVAL; + + udev->cur_xfer_blks = size; + return 0; +} + /******************************************************************************* * show info on storage devices; 'usb start/init' must be invoked earlier * as we only retrieve structures populated during devices initialization @@ -1126,6 +1169,7 @@ static unsigned long usb_stor_read_write(struct blk_desc *block_dev, struct usb_device *udev; struct us_data *ss; int retry; + bool retry_flag = false; ccb *srb = &usb_ccb; #ifdef CONFIG_BLK struct blk_desc *block_dev; @@ -1164,26 +1208,37 @@ static unsigned long usb_stor_read_write(struct blk_desc *block_dev, */ 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_%s: retry #%d, cur_xfer_blks %hu, smallblks %hu\n", + USB_STOR_OPERATION, 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_STOR_OPERATION_FUNC(srb, ss, start, smallblks)) { debug("%s ERROR\n", USB_STOR_OPERATION); usb_request_sense(srb, ss); - if (retry--) + if (retry--) { + if (!dec_cur_xfer_blks(udev)) + smallblks = udev->cur_xfer_blks; + retry_flag = true; goto retry_it; + } blkcnt -= blks; break; } start += smallblks; blks -= smallblks; buf_addr += srb->datalen; + + if (!retry_flag && !inc_cur_xfer_blks(udev, blks)) + smallblks = udev->cur_xfer_blks; + } while (blks != 0); ss->flags &= ~USB_READY;
@@ -1192,7 +1247,7 @@ retry_it: USB_STOR_OPERATION, 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; } @@ -1291,6 +1346,9 @@ 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..b815816 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;