diff options
Diffstat (limited to 'payloads/libpayload/drivers/usb')
| -rw-r--r-- | payloads/libpayload/drivers/usb/ehci.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/payloads/libpayload/drivers/usb/ehci.c b/payloads/libpayload/drivers/usb/ehci.c index b83712c463..7002623e49 100644 --- a/payloads/libpayload/drivers/usb/ehci.c +++ b/payloads/libpayload/drivers/usb/ehci.c @@ -30,6 +30,7 @@ //#define USB_DEBUG #include <libpayload.h> +#include <arch/barrier.h> #include <arch/cache.h> #include "ehci.h" #include "ehci_private.h" @@ -317,6 +318,14 @@ static int wait_for_tds(qtd_t *head) static int ehci_set_async_schedule(ehci_t *ehcic, int enable) { + + /* Memory barrier to ensure that all memory accesses before we set the + * async schedule are complete. It was observed especially in the case of + * arm64, that netboot and usb stuff resulted in lots of errors possibly + * due to CPU reordering. Hence, enforcing strict CPU ordering. + */ + mb(); + /* Set async schedule status. */ if (enable) ehcic->operation->usbcmd |= HC_OP_ASYNC_SCHED_EN; |