Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753357AbaKYNP4 (ORCPT ); Tue, 25 Nov 2014 08:15:56 -0500 Received: from devils.ext.ti.com ([198.47.26.153]:54401 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753164AbaKYNPx (ORCPT ); Tue, 25 Nov 2014 08:15:53 -0500 From: George Cherian To: , , , , CC: , , , , , , , , , , , , , , , George Cherian Subject: [PATCH 04/19] usb: host xhci: Add XHCI_NEEDS_LHC_RESET quirk Date: Tue, 25 Nov 2014 18:41:40 +0530 Message-ID: <1416921115-10467-5-git-send-email-george.cherian@ti.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1416921115-10467-1-git-send-email-george.cherian@ti.com> References: <1416921115-10467-1-git-send-email-george.cherian@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This adds XHCI_NEEDS_LHC_RESET quirk, to make sure only Light Host Reset is done during xhci_reset(). This is mainly useful when we switch roles HOST to Device mode and viceversa. The DWC3 IP shares internal RAM for both HOST and Device specific registers. So while switching roles between HOST and Device modes, it's advbised to do a LIGHT HC reset else the already configured global registers of the DWC3 IP gets re-initialized. Signed-off-by: George Cherian --- drivers/usb/host/xhci.c | 5 +++-- drivers/usb/host/xhci.h | 1 + 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c index d4196f8..5dabf9a 100644 --- a/drivers/usb/host/xhci.c +++ b/drivers/usb/host/xhci.c @@ -170,11 +170,12 @@ int xhci_reset(struct xhci_hcd *xhci) xhci_dbg_trace(xhci, trace_xhci_dbg_init, "// Reset the HC"); command = readl(&xhci->op_regs->command); - command |= CMD_RESET; + command |= (xhci->quirks & XHCI_NEEDS_LHC_RESET) ? CMD_LRESET : CMD_RESET; writel(command, &xhci->op_regs->command); ret = xhci_handshake(xhci, &xhci->op_regs->command, - CMD_RESET, 0, 10 * 1000 * 1000); + (xhci->quirks & XHCI_NEEDS_LHC_RESET) ? CMD_LRESET : CMD_RESET, + 0, 10 * 1000 * 1000); if (ret) return ret; diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 2248058..1b14b09 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -1561,6 +1561,7 @@ struct xhci_hcd { /* For controllers with a broken beyond repair streams implementation */ #define XHCI_BROKEN_STREAMS (1 << 19) #define XHCI_DRD_SUPPORT (1 << 20) +#define XHCI_NEEDS_LHC_RESET (1 << 21) unsigned int num_active_eps; unsigned int limit_active_eps; /* There are two roothubs to keep track of bus suspend info for */ -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/