On some xHCI controllers (e.g. R-Car SoCs), the AC64 bit (bit 0) of
HCCPARAMS1 is set to 1. However, the xHCs don't support 64-bit
address memory pointers actually. So, in this case, this driver should
call dma_set_coherent_mask(dev, DMA_BIT_MASK(32)) in xhci_gen_setup().
Otherwise, the xHCI controller will be died after a usb device is
connected if it runs on above 4GB physical memory environment.
So, this patch adds a new quirk XHCI_CLEAR_AC64 to resolve such an issue.
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@xxxxxxxxxxx>
---
drivers/usb/host/xhci.c | 10 ++++++++++
drivers/usb/host/xhci.h | 1 +
2 files changed, 11 insertions(+)
diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index d51ee0c..4b5e979 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -4948,6 +4948,16 @@ int xhci_gen_setup(struct usb_hcd *hcd, xhci_get_quirks_t get_quirks)
return retval;
xhci_dbg(xhci, "Reset complete\n");
+ /*
+ * On some xHCI controllers (e.g. R-Car SoCs), the AC64 bit (bit 0)
+ * of HCCPARAMS1 is set to 1. However, the xHCs don't support 64-bit
+ * address memory pointers actually. So, this driver clears the AC64
+ * bit of xhci->hcc_params to call dma_set_coherent_mask(dev,
+ * DMA_BIT_MASK(32)) in this xhci_gen_setup().
+ */
+ if (xhci->quirks & XHCI_CLEAR_AC64)
+ xhci->hcc_params &= ~BIT(0);
+
/* Set dma_mask and coherent_dma_mask to 64-bits,
* if xHC supports 64-bit addressing */
if (HCC_64BIT_ADDR(xhci->hcc_params) &&
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
index e293e09..1963148 100644
--- a/drivers/usb/host/xhci.h
+++ b/drivers/usb/host/xhci.h
@@ -1641,6 +1641,7 @@ struct xhci_hcd {
#define XHCI_PME_STUCK_QUIRK (1 << 20)
#define XHCI_MTK_HOST (1 << 21)
#define XHCI_SSIC_PORT_UNUSED (1 << 22)
+#define XHCI_CLEAR_AC64 (1 << 23)
unsigned int num_active_eps;
unsigned int limit_active_eps;
/* There are two roothubs to keep track of bus suspend info for */
--
1.9.1
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