Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934093Ab0BYVXw (ORCPT ); Thu, 25 Feb 2010 16:23:52 -0500 Received: from mail.windriver.com ([147.11.1.11]:63864 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934076Ab0BYVXi (ORCPT ); Thu, 25 Feb 2010 16:23:38 -0500 From: Jason Wessel To: torvalds@linux-foundation.org Cc: linux-kernel@vger.kernel.org, kgdb-bugreport@lists.sourceforge.net, Jason Wessel , Eric Biederman , Yinghai Lu , linux-usb@vger.kernel.org Subject: [PATCH 7/8] ehci-dbgp: split PID register updates for IN and OUT pipes Date: Thu, 25 Feb 2010 15:22:05 -0600 Message-Id: <1267132926-23685-8-git-send-email-jason.wessel@windriver.com> X-Mailer: git-send-email 1.6.4.rc1 In-Reply-To: <1267132926-23685-1-git-send-email-jason.wessel@windriver.com> References: <1267132926-23685-1-git-send-email-jason.wessel@windriver.com> X-OriginalArrivalTime: 25 Feb 2010 21:22:51.0507 (UTC) FILETIME=[AFBE2430:01CAB660] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4968 Lines: 171 This patch addresses two problems: 1) Bulk reads should always use the DATA0 for the pid, and the write PID should toggle between DATA0 and DATA1. The fix is using dbgp_pid_write_update() and dbgp_pid_read_update(). 2) The delay loop for waiting for a transaction was not long enough to always complete the initial handshake inside dbgp_wait_until_done(). After the initial handshake the maximum delay length is never reached. The combined result of these two changes allows for the removal of the forced resynchronization where a bulk write was issued with a dummy data payload only to get the device to start accepting data writes again. CC: Eric Biederman CC: Yinghai Lu CC: linux-usb@vger.kernel.org Signed-off-by: Jason Wessel Acked-by: Greg Kroah-Hartman --- drivers/usb/early/ehci-dbgp.c | 68 +++++++++++++++++------------------------ 1 files changed, 28 insertions(+), 40 deletions(-) diff --git a/drivers/usb/early/ehci-dbgp.c b/drivers/usb/early/ehci-dbgp.c index 2958a12..6e98a36 100644 --- a/drivers/usb/early/ehci-dbgp.c +++ b/drivers/usb/early/ehci-dbgp.c @@ -66,8 +66,6 @@ static struct ehci_dev ehci_dev; #define USB_DEBUG_DEVNUM 127 -#define DBGP_DATA_TOGGLE 0x8800 - #ifdef DBGP_DEBUG #define dbgp_printk printk static void dbgp_ehci_status(char *str) @@ -88,11 +86,6 @@ static inline void dbgp_ehci_status(char *str) { } static inline void dbgp_printk(const char *fmt, ...) { } #endif -static inline u32 dbgp_pid_update(u32 x, u32 tok) -{ - return ((x ^ DBGP_DATA_TOGGLE) & 0xffff00) | (tok & 0xff); -} - static inline u32 dbgp_len_update(u32 x, u32 len) { return (x & ~0x0f) | (len & 0x0f); @@ -136,6 +129,19 @@ static inline u32 dbgp_len_update(u32 x, u32 len) #define DBGP_MAX_PACKET 8 #define DBGP_TIMEOUT (250 * 1000) +#define DBGP_LOOPS 1000 + +static inline u32 dbgp_pid_write_update(u32 x, u32 tok) +{ + static int data0 = USB_PID_DATA1; + data0 ^= USB_PID_DATA_TOGGLE; + return (x & 0xffff0000) | (data0 << 8) | (tok & 0xff); +} + +static inline u32 dbgp_pid_read_update(u32 x, u32 tok) +{ + return (x & 0xffff0000) | (USB_PID_DATA0 << 8) | (tok & 0xff); +} static int dbgp_wait_until_complete(void) { @@ -180,7 +186,7 @@ static int dbgp_wait_until_done(unsigned ctrl) { u32 pids, lpid; int ret; - int loop = 3; + int loop = DBGP_LOOPS; retry: writel(ctrl | DBGP_GO, &ehci_debug->control); @@ -197,6 +203,8 @@ retry: */ if (ret == -DBGP_TIMEOUT && !dbgp_not_safe) dbgp_not_safe = 1; + if (ret == -DBGP_ERR_BAD && --loop > 0) + goto retry; return ret; } @@ -245,12 +253,20 @@ static inline void dbgp_get_data(void *buf, int size) bytes[i] = (hi >> (8*(i - 4))) & 0xff; } -static int dbgp_out(u32 addr, const char *bytes, int size) +static int dbgp_bulk_write(unsigned devnum, unsigned endpoint, + const char *bytes, int size) { + int ret; + u32 addr; u32 pids, ctrl; + if (size > DBGP_MAX_PACKET) + return -1; + + addr = DBGP_EPADDR(devnum, endpoint); + pids = readl(&ehci_debug->pids); - pids = dbgp_pid_update(pids, USB_PID_OUT); + pids = dbgp_pid_write_update(pids, USB_PID_OUT); ctrl = readl(&ehci_debug->control); ctrl = dbgp_len_update(ctrl, size); @@ -260,34 +276,7 @@ static int dbgp_out(u32 addr, const char *bytes, int size) dbgp_set_data(bytes, size); writel(addr, &ehci_debug->address); writel(pids, &ehci_debug->pids); - return dbgp_wait_until_done(ctrl); -} - -static int dbgp_bulk_write(unsigned devnum, unsigned endpoint, - const char *bytes, int size) -{ - int ret; - int loops = 5; - u32 addr; - if (size > DBGP_MAX_PACKET) - return -1; - - addr = DBGP_EPADDR(devnum, endpoint); -try_again: - if (loops--) { - ret = dbgp_out(addr, bytes, size); - if (ret == -DBGP_ERR_BAD) { - int try_loops = 3; - do { - /* Emit a dummy packet to re-sync communication - * with the debug device */ - if (dbgp_out(addr, "12345678", 8) >= 0) { - udelay(2); - goto try_again; - } - } while (try_loops--); - } - } + ret = dbgp_wait_until_done(ctrl); return ret; } @@ -304,7 +293,7 @@ static int dbgp_bulk_read(unsigned devnum, unsigned endpoint, void *data, addr = DBGP_EPADDR(devnum, endpoint); pids = readl(&ehci_debug->pids); - pids = dbgp_pid_update(pids, USB_PID_IN); + pids = dbgp_pid_read_update(pids, USB_PID_IN); ctrl = readl(&ehci_debug->control); ctrl = dbgp_len_update(ctrl, size); @@ -362,7 +351,6 @@ static int dbgp_control_msg(unsigned devnum, int requesttype, return dbgp_bulk_read(devnum, 0, data, size); } - /* Find a PCI capability */ static u32 __init find_cap(u32 num, u32 slot, u32 func, int cap) { -- 1.6.4.rc1 -- 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/