Hi, On 01.03.21 12:07, Ahmad Fatoum wrote: > Some USB disks take notoriously long to spin up. They are seen by a bus > scan, but they report ready only after a few seconds have passed. This > is not a problem if vbus is enabled early on, so devices have had a > chance to spin up. If vbus is first enabled as part of the usb scan, > not enough time might have passed for the USB disk to be usable. > > This issue was observed on an i.MX6QP with following topology: > > usb: USB: scanning bus for devices... > usb: 5 USB Device(s) found > 1 ID 0000:0000 > | u-boot EHCI Host Controller > | > +-2 ID 0424:2517 > | > +-5 ID 1058:2621 > | Western Digital Elements 2621 > ... > > Unplugging and replugging the USB disk and doing a second usb scan > made the unit ready test succeed. By increasing the retry count > during initialization, this workaround is no longer necessary.
Please dismiss for now. This doesn't always work, even for my HDD. > Signed-off-by: Ahmad Fatoum <[email protected]> > --- > drivers/usb/storage/usb.c | 9 +++++---- > 1 file changed, 5 insertions(+), 4 deletions(-) > > diff --git a/drivers/usb/storage/usb.c b/drivers/usb/storage/usb.c > index b417640186a2..7b0aecd757b0 100644 > --- a/drivers/usb/storage/usb.c > +++ b/drivers/usb/storage/usb.c > @@ -141,7 +141,7 @@ exit: > return ret; > } > > -static int usb_stor_test_unit_ready(struct us_blk_dev *usb_blkdev) > +static int usb_stor_test_unit_ready(struct us_blk_dev *usb_blkdev, int > retries) > { > u8 cmd[6]; > int ret; > @@ -150,7 +150,7 @@ static int usb_stor_test_unit_ready(struct us_blk_dev > *usb_blkdev) > cmd[0] = SCSI_TST_U_RDY; > > ret = usb_stor_transport(usb_blkdev, cmd, sizeof(cmd), NULL, 0, > - 10, 100); > + retries, 100); > if (ret < 0) > return -ENODEV; > > @@ -282,7 +282,7 @@ static int usb_stor_blk_io(struct block_device *disk_dev, > > /* ensure unit ready */ > dev_dbg(dev, "Testing for unit ready\n"); > - if (usb_stor_test_unit_ready(pblk_dev)) { > + if (usb_stor_test_unit_ready(pblk_dev, 10)) { > dev_dbg(dev, "Device NOT ready\n"); > return -EIO; > } > @@ -365,7 +365,8 @@ static int usb_stor_init_blkdev(struct us_blk_dev > *pblk_dev) > /* ensure unit ready */ > dev_dbg(dev, "Testing for unit ready\n"); > > - result = usb_stor_test_unit_ready(pblk_dev); > + /* retry a bit longer than usual as some HDDs take longer to spin up */ > + result = usb_stor_test_unit_ready(pblk_dev, 60); > if (result) { > dev_dbg(dev, "Device NOT ready\n"); > return result; > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list [email protected] http://lists.infradead.org/mailman/listinfo/barebox
