On 2019-10-25 8:30 a.m., Gilles DOFFE wrote:
Some USB sticks cannot handle SIZE_MAX bytes (65535) blocks transfer, leading to 'EHCI timed out on TD' errors. As it is hardly predictable, this commit adds a configuration option to easily reduce this EHCI max transfer size. The default value is 65535 which corresponds to size_t max value (SIZE_MAX).
This doesn't seem like an ideal solution, as one would have to rebuild U-Boot to cope with such a device. Do you know how the Linux kernel EHCI driver deals with this problem?
Signed-off-by: Gilles DOFFE gilles.doffe@savoirfairelinux.com
drivers/usb/host/Kconfig | 7 +++++++ drivers/usb/host/ehci-hcd.c | 2 +- 2 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig index 30c6b69be8..62054c9c7a 100644 --- a/drivers/usb/host/Kconfig +++ b/drivers/usb/host/Kconfig @@ -222,6 +222,13 @@ config USB_EHCI_FSL select CONFIG_EHCI_HCD_INIT_AFTER_RESET ---help--- Enables support for the on-chip EHCI controller on FSL chips.
+config USB_EHCI_MAX_XFER_SIZE
- int "USB EHCI max transfer size. The default value is 65535 which
- corresponds to size_t max value (SIZE_MAX)."
- default 65535
- range 1 65535
endif # USB_EHCI_HCD
config USB_OHCI_HCD diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index 61a61abb21..8be1319079 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -1614,7 +1614,7 @@ static int ehci_get_max_xfer_size(struct udevice *dev, size_t *size) * EHCD can handle any transfer length as long as there is enough * free heap space left, hence set the theoretical max number here. */
- *size = SIZE_MAX;
*size = CONFIG_USB_EHCI_MAX_XFER_SIZE;
return 0;
}