From 3d9545cc375d117554a9b35dfddadf9189c62775 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Mon, 23 Apr 2012 13:54:36 -0400 Subject: [PATCH] EHCI: maintain the ehci->command value properly The ehci-hcd driver is a little haphazard about keeping track of the state of the USBCMD register. The ehci->command field is supposed to hold the register's value (apart from a few special bits) at all times, but it isn't maintained properly. This patch (as1543) cleans up the situation. It keeps ehci->command up-to-date, and uses that value rather than reading the register from the hardware whenever possible. Signed-off-by: Alan Stern Signed-off-by: Greg Kroah-Hartman --- drivers/usb/host/ehci-dbg.c | 6 ++---- drivers/usb/host/ehci-hcd.c | 16 ++++++++++------ drivers/usb/host/ehci-hub.c | 2 +- drivers/usb/host/ehci-q.c | 16 ++++++---------- drivers/usb/host/ehci-sched.c | 10 ++++------ 5 files changed, 23 insertions(+), 27 deletions(-) diff --git a/drivers/usb/host/ehci-dbg.c b/drivers/usb/host/ehci-dbg.c index 680e1a31fb87c2..7561966fbdc40e 100644 --- a/drivers/usb/host/ehci-dbg.c +++ b/drivers/usb/host/ehci-dbg.c @@ -1025,10 +1025,8 @@ static ssize_t debug_lpm_write(struct file *file, const char __user *user_buf, if (strict_strtoul(buf + 5, 16, &hird)) return -EINVAL; printk(KERN_INFO "setting hird %s %lu\n", buf + 6, hird); - temp = ehci_readl(ehci, &ehci->regs->command); - temp &= ~CMD_HIRD; - temp |= hird << 24; - ehci_writel(ehci, temp, &ehci->regs->command); + ehci->command = (ehci->command & ~CMD_HIRD) | (hird << 24); + ehci_writel(ehci, ehci->command, &ehci->regs->command); } else if (strncmp(buf, "disable", 7) == 0) { if (strict_strtoul(buf + 8, 10, &port)) return -EINVAL; diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index a87c0573c860c7..de1e689d3df08f 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -226,8 +226,13 @@ static int ehci_halt (struct ehci_hcd *ehci) if ((temp & STS_HALT) != 0) return 0; + /* + * This routine gets called during probe before ehci->command + * has been initialized, so we can't rely on its value. + */ + ehci->command &= ~CMD_RUN; temp = ehci_readl(ehci, &ehci->regs->command); - temp &= ~CMD_RUN; + temp &= ~(CMD_RUN | CMD_IAAD); ehci_writel(ehci, temp, &ehci->regs->command); return handshake (ehci, &ehci->regs->status, STS_HALT, STS_HALT, 16 * 125); @@ -347,6 +352,7 @@ static int ehci_reset (struct ehci_hcd *ehci) if (ehci->debug) dbgp_external_startup(); + ehci->command = ehci_readl(ehci, &ehci->regs->command); ehci->port_c_suspend = ehci->suspended_ports = ehci->resuming_ports = 0; return retval; @@ -363,16 +369,14 @@ static void ehci_quiesce (struct ehci_hcd *ehci) #endif /* wait for any schedule enables/disables to take effect */ - temp = ehci_readl(ehci, &ehci->regs->command) << 10; - temp &= STS_ASS | STS_PSS; + temp = (ehci->command << 10) & (STS_ASS | STS_PSS); if (handshake_on_error_set_halt(ehci, &ehci->regs->status, STS_ASS | STS_PSS, temp, 16 * 125)) return; /* then disable anything that's still active */ - temp = ehci_readl(ehci, &ehci->regs->command); - temp &= ~(CMD_ASE | CMD_IAAD | CMD_PSE); - ehci_writel(ehci, temp, &ehci->regs->command); + ehci->command &= ~(CMD_ASE | CMD_PSE); + ehci_writel(ehci, ehci->command, &ehci->regs->command); /* hardware can take 16 microframes to turn off ... */ handshake_on_error_set_halt(ehci, &ehci->regs->status, diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c index 402e766df2fe5c..fc9e7cc6ac9b90 100644 --- a/drivers/usb/host/ehci-hub.c +++ b/drivers/usb/host/ehci-hub.c @@ -233,7 +233,6 @@ static int ehci_bus_suspend (struct usb_hcd *hcd) /* stop schedules, clean any completed work */ if (ehci->rh_state == EHCI_RH_RUNNING) ehci_quiesce (ehci); - ehci->command = ehci_readl(ehci, &ehci->regs->command); ehci_work(ehci); /* Unlike other USB host controller types, EHCI doesn't have @@ -374,6 +373,7 @@ static int ehci_bus_resume (struct usb_hcd *hcd) ehci_writel(ehci, (u32) ehci->async->qh_dma, &ehci->regs->async_next); /* restore CMD_RUN, framelist size, and irq threshold */ + ehci->command |= CMD_RUN; ehci_writel(ehci, ehci->command, &ehci->regs->command); ehci->rh_state = EHCI_RH_RUNNING; diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c index 36ca5077cdf79d..13f4f980841af4 100644 --- a/drivers/usb/host/ehci-q.c +++ b/drivers/usb/host/ehci-q.c @@ -981,14 +981,12 @@ static void qh_link_async (struct ehci_hcd *ehci, struct ehci_qh *qh) head = ehci->async; timer_action_done (ehci, TIMER_ASYNC_OFF); if (!head->qh_next.qh) { - u32 cmd = ehci_readl(ehci, &ehci->regs->command); - - if (!(cmd & CMD_ASE)) { + if (!(ehci->command & CMD_ASE)) { /* in case a clear of CMD_ASE didn't take yet */ (void)handshake(ehci, &ehci->regs->status, STS_ASS, 0, 150); - cmd |= CMD_ASE; - ehci_writel(ehci, cmd, &ehci->regs->command); + ehci->command |= CMD_ASE; + ehci_writel(ehci, ehci->command, &ehci->regs->command); /* posted write need not be known to HC yet ... */ } } @@ -1204,7 +1202,6 @@ static void end_unlink_async (struct ehci_hcd *ehci) static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh) { - int cmd = ehci_readl(ehci, &ehci->regs->command); struct ehci_qh *prev; #ifdef DEBUG @@ -1222,8 +1219,8 @@ static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh) if (ehci->rh_state != EHCI_RH_HALTED && !ehci->reclaim) { /* ... and CMD_IAAD clear */ - ehci_writel(ehci, cmd & ~CMD_ASE, - &ehci->regs->command); + ehci->command &= ~CMD_ASE; + ehci_writel(ehci, ehci->command, &ehci->regs->command); wmb (); // handshake later, if we need to timer_action_done (ehci, TIMER_ASYNC_OFF); @@ -1253,8 +1250,7 @@ static void start_unlink_async (struct ehci_hcd *ehci, struct ehci_qh *qh) return; } - cmd |= CMD_IAAD; - ehci_writel(ehci, cmd, &ehci->regs->command); + ehci_writel(ehci, ehci->command | CMD_IAAD, &ehci->regs->command); (void)ehci_readl(ehci, &ehci->regs->command); iaa_watchdog_start(ehci); } diff --git a/drivers/usb/host/ehci-sched.c b/drivers/usb/host/ehci-sched.c index a60679cbbf858e..ffe8fc3bc7efa9 100644 --- a/drivers/usb/host/ehci-sched.c +++ b/drivers/usb/host/ehci-sched.c @@ -481,7 +481,6 @@ static int tt_no_collision ( static int enable_periodic (struct ehci_hcd *ehci) { - u32 cmd; int status; if (ehci->periodic_sched++) @@ -497,8 +496,8 @@ static int enable_periodic (struct ehci_hcd *ehci) return status; } - cmd = ehci_readl(ehci, &ehci->regs->command) | CMD_PSE; - ehci_writel(ehci, cmd, &ehci->regs->command); + ehci->command |= CMD_PSE; + ehci_writel(ehci, ehci->command, &ehci->regs->command); /* posted write ... PSS happens later */ /* make sure ehci_work scans these */ @@ -511,7 +510,6 @@ static int enable_periodic (struct ehci_hcd *ehci) static int disable_periodic (struct ehci_hcd *ehci) { - u32 cmd; int status; if (--ehci->periodic_sched) @@ -537,8 +535,8 @@ static int disable_periodic (struct ehci_hcd *ehci) return status; } - cmd = ehci_readl(ehci, &ehci->regs->command) & ~CMD_PSE; - ehci_writel(ehci, cmd, &ehci->regs->command); + ehci->command &= ~CMD_PSE; + ehci_writel(ehci, ehci->command, &ehci->regs->command); /* posted write ... */ free_cached_lists(ehci);