When the EHCI controller received a 512 byte USB packet that
had to be broken into 2 256 byte bursts across the SCB bus AND
there was a following 512 byte USB packet, the second burst of
data from the first packet was sometimes being lost. If the
burst size was changed to 128 bytes via the EBR_SCB_SIZE field
in the USB_CTRL_EBRIDGE register we'd see the 4th 128 byte burst
of the first packet being lost. This problem became much worse
if other threads were running that accessed memory, like a memcpy
test. Setting the EBR_SCB_SIZE to 512, which prevents breaking
the EHCI USB packet (max size of 512 bytes) into bursts, fixed
the problem.
Signed-off-by: Al Cooper <alcooperx@xxxxxxxxx>
---
drivers/phy/broadcom/phy-brcm-usb-init.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/phy/broadcom/phy-brcm-usb-init.c b/drivers/phy/broadcom/phy-brcm-usb-init.c
index 3c53625f8bc2..56d9b314a8d0 100644
--- a/drivers/phy/broadcom/phy-brcm-usb-init.c
+++ b/drivers/phy/broadcom/phy-brcm-usb-init.c
@@ -42,6 +42,7 @@
#define USB_CTRL_PLL_CTL_PLL_IDDQ_PWRDN_MASK 0x80000000 /* option */
#define USB_CTRL_EBRIDGE 0x0c
#define USB_CTRL_EBRIDGE_ESTOP_SCB_REQ_MASK 0x00020000 /* option */
+#define USB_CTRL_EBRIDGE_EBR_SCB_SIZE_MASK 0x00000f80 /* option */
#define USB_CTRL_OBRIDGE 0x10
#define USB_CTRL_OBRIDGE_LS_KEEP_ALIVE_MASK 0x08000000
#define USB_CTRL_MDIO 0x14
@@ -176,6 +177,7 @@ static const struct id_to_type id_to_type_table[] = {
{ 0x33900000, BRCM_FAMILY_3390A0 },
{ 0x72500010, BRCM_FAMILY_7250B0 },
{ 0x72600000, BRCM_FAMILY_7260A0 },
+ { 0x72550000, BRCM_FAMILY_7260A0 },
{ 0x72680000, BRCM_FAMILY_7271A0 },
{ 0x72710000, BRCM_FAMILY_7271A0 },
{ 0x73640000, BRCM_FAMILY_7364A0 },
@@ -948,6 +950,17 @@ void brcm_usb_init_eohci(struct brcm_usb_init_params *params)
if (params->selected_family == BRCM_FAMILY_7271A0)
/* Enable LS keep alive fix for certain keyboards */
USB_CTRL_SET(ctrl, OBRIDGE, LS_KEEP_ALIVE);
+
+ if (params->family_id == 0x72550000) {
+ /*
+ * Make the burst size 512 bytes to fix a hardware bug
+ * on the 7255a0. See HW7255-24.
+ */
+ reg = brcmusb_readl(USB_CTRL_REG(ctrl, EBRIDGE));
+ reg &= ~USB_CTRL_MASK(EBRIDGE, EBR_SCB_SIZE);
+ reg |= 0x800;
+ brcmusb_writel(reg, USB_CTRL_REG(ctrl, EBRIDGE));
+ }
}
void brcm_usb_init_xhci(struct brcm_usb_init_params *params)
--
2.17.1
