Hi Jim, On Thu, Jul 26, 2012 at 10:20:48 PM, Jim Shimer wrote: > I'm seeing a 5ms delay in usb_stor_BBB_transport, which occurs every > 10K of > data for fatload usb or 500ms of delay per 1MB of image size. This > adds up > to quite a bit of delay if you're loading a large ramdisk. > > Does anyone know what the reason for the 5ms delay really is? I'm > assuming > that this delay is to debounce the 5V/100ma USB power up. I made > some > modification, where the delay is skipped if the device has already > been > queried as ready. This has save me 500ms/M on fatload times (eg, > 140M=70seconds). Is there anything wrong with this tweak? > > Here's a diff of what I've done to get the performance I need: > > --- usb_storage.c.orig 2012-07-26 16:06:40.775251000 -0400 > +++ usb_storage.c 2012-07-26 13:49:36.000000000 -0400 > @@ -132,6 +132,7 @@ static block_dev_desc_t usb_dev_desc[USB > struct us_data; > typedef int (*trans_cmnd)(ccb *cb, struct us_data *data); > typedef int (*trans_reset)(struct us_data *data); > +typedef enum us_status { USB_NOT_READY, USB_READY} us_status; > > struct us_data { > struct usb_device *pusb_dev; /* this usb_device */ > @@ -154,6 +155,7 @@ struct us_data { > ccb *srb; /* current srb */ > trans_reset transport_reset; /* reset routine */ > trans_cmnd transport; /* transport routine > */ > + us_status status; > }; > > static struct us_data usb_stor[USB_MAX_STOR_DEV]; > @@ -691,7 +693,10 @@ int usb_stor_BBB_transport(ccb *srb, str > usb_stor_BBB_reset(us); > return USB_STOR_TRANSPORT_FAILED; > } > - wait_ms(5); > + if(us->status != USB_READY) > + { > + wait_ms(5); > + } > pipein = usb_rcvbulkpipe(us->pusb_dev, us->ep_in); > pipeout = usb_sndbulkpipe(us->pusb_dev, us->ep_out); > /* DATA phase + error handling */ > @@ -957,7 +962,10 @@ static int usb_test_unit_ready(ccb *srb, > srb->datalen = 0; > srb->cmdlen = 12; > if (ss->transport(srb, ss) == > USB_STOR_TRANSPORT_GOOD) > + { > + ss->status = USB_READY; > return 0; > + } > usb_request_sense(srb, ss); > wait_ms(100); > } while (retries--); > @@ -965,6 +973,11 @@ static int usb_test_unit_ready(ccb *srb, > return -1; > } > > +static void usb_set_unit_not_ready(struct us_data *ss) > +{ > + ss->status = USB_NOT_READY; > +} > + > static int usb_read_capacity(ccb *srb, struct us_data *ss) > { > int retry; > @@ -1108,6 +1121,7 @@ retry_it: > blks -= smallblks; > buf_addr += srb->datalen; > } while (blks != 0); > + usb_set_unit_not_ready((struct us_data *)dev->privptr); > > USB_STOR_PRINTF("usb_read: end startblk %lx, blccnt %x buffer > %lx\n", > start, smallblks, buf_addr); > @@ -1188,6 +1202,7 @@ retry_it: > blks -= smallblks; > buf_addr += srb->datalen; > } while (blks != 0); > + usb_set_unit_not_ready((struct us_data *)dev->privptr); > > USB_STOR_PRINTF("usb_write: end startblk %lx, blccnt %x > buffer > %lx\n", > start, smallblks, buf_addr); > @@ -1398,6 +1413,7 @@ int usb_stor_get_info(struct usb_device > cap[0] = 2880; > cap[1] = 0x200; > } > + usb_set_unit_not_ready((struct us_data *)dev->privptr); > USB_STOR_PRINTF("Read Capacity returns: 0x%lx, 0x%lx\n", > cap[0], > cap[1]); > #if 0 > > > I'd appreciate any feedback. > Regards
I have not looked into this delay issue, but I had similar performance issues that I fixed with the following series: http://patchwork.ozlabs.org/patch/172052/ http://patchwork.ozlabs.org/patch/172204/ http://patchwork.ozlabs.org/patch/172054/ http://patchwork.ozlabs.org/patch/172055/ http://patchwork.ozlabs.org/patch/172056/ Your suggestion is interesting and might be a complement to my series. I don't have time to check its correctness right now, but I'll try soon. Best regards, Benoît _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot