* [PATCH 2/2] usb: dwc2: host: Clear interrupts before handling them
2015-10-16 22:10 [PATCH 1/2] usb: dwc2: host: Fix missing device insertions Douglas Anderson
@ 2015-10-16 22:10 ` Douglas Anderson
2015-10-30 20:38 ` [PATCH 1/2] usb: dwc2: host: Fix missing device insertions John Youn
1 sibling, 0 replies; 4+ messages in thread
From: Douglas Anderson @ 2015-10-16 22:10 UTC (permalink / raw)
To: John Youn, balbi
Cc: Yunzhi Li, Heiko Stübner, linux-rockchip, Julius Werner,
gregory.herrero, yousaf.kaukab, dinguyen, Douglas Anderson,
johnyoun, gregkh, linux-usb, linux-kernel
In general it is wise to interrupts before processing them. If you
don't do that, you can get:
1. Interrupt happens
2. You look at system state and process interrupt
3. A new interrupt happens
4. You clear interrupt without processing it.
This patch was actually a first attempt to fix missing device insertions
as described in (usb: dwc2: host: Fix missing device insertions) and it
did solve some of the signal bouncing problems but not all of
them (which is why I submitted the other patch). Specifically, this
patch itself would sometimes change:
1. hardware sees connect
2. hardware sees disconnect
3. hardware sees connect
4. dwc2_port_intr() - clears connect interrupt
5. dwc2_handle_common_intr() - calls dwc2_hcd_disconnect()
...to:
1. hardware sees connect
2. hardware sees disconnect
3. dwc2_port_intr() - clears connect interrupt
4. hardware sees connect
5. dwc2_handle_common_intr() - calls dwc2_hcd_disconnect()
...but with different timing then sometimes we'd still miss cable
insertions.
In any case, though this patch doesn't fix any (known) problems, it
still seems wise as a general policy to clear interrupt before handling
them.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
---
drivers/usb/dwc2/core_intr.c | 55 ++++++++++++++++++++++----------------------
drivers/usb/dwc2/hcd_intr.c | 16 ++++++-------
2 files changed, 35 insertions(+), 36 deletions(-)
diff --git a/drivers/usb/dwc2/core_intr.c b/drivers/usb/dwc2/core_intr.c
index 27daa42..7899e02 100644
--- a/drivers/usb/dwc2/core_intr.c
+++ b/drivers/usb/dwc2/core_intr.c
@@ -80,15 +80,16 @@ static const char *dwc2_op_state_str(struct dwc2_hsotg *hsotg)
*/
static void dwc2_handle_usb_port_intr(struct dwc2_hsotg *hsotg)
{
- u32 hprt0 = dwc2_readl(hsotg->regs + HPRT0);
+ u32 hprt0;
+ /* Clear interrupt */
+ dwc2_writel(GINTSTS_PRTINT, hsotg->regs + GINTSTS);
+
+ hprt0 = dwc2_readl(hsotg->regs + HPRT0);
if (hprt0 & HPRT0_ENACHG) {
hprt0 &= ~HPRT0_ENA;
dwc2_writel(hprt0, hsotg->regs + HPRT0);
}
-
- /* Clear interrupt */
- dwc2_writel(GINTSTS_PRTINT, hsotg->regs + GINTSTS);
}
/**
@@ -98,11 +99,11 @@ static void dwc2_handle_usb_port_intr(struct dwc2_hsotg *hsotg)
*/
static void dwc2_handle_mode_mismatch_intr(struct dwc2_hsotg *hsotg)
{
- dev_warn(hsotg->dev, "Mode Mismatch Interrupt: currently in %s mode\n",
- dwc2_is_host_mode(hsotg) ? "Host" : "Device");
-
/* Clear interrupt */
dwc2_writel(GINTSTS_MODEMIS, hsotg->regs + GINTSTS);
+
+ dev_warn(hsotg->dev, "Mode Mismatch Interrupt: currently in %s mode\n",
+ dwc2_is_host_mode(hsotg) ? "Host" : "Device");
}
/**
@@ -276,9 +277,13 @@ static void dwc2_handle_otg_intr(struct dwc2_hsotg *hsotg)
*/
static void dwc2_handle_conn_id_status_change_intr(struct dwc2_hsotg *hsotg)
{
- u32 gintmsk = dwc2_readl(hsotg->regs + GINTMSK);
+ u32 gintmsk;
+
+ /* Clear interrupt */
+ dwc2_writel(GINTSTS_CONIDSTSCHNG, hsotg->regs + GINTSTS);
/* Need to disable SOF interrupt immediately */
+ gintmsk = dwc2_readl(hsotg->regs + GINTMSK);
gintmsk &= ~GINTSTS_SOF;
dwc2_writel(gintmsk, hsotg->regs + GINTMSK);
@@ -295,9 +300,6 @@ static void dwc2_handle_conn_id_status_change_intr(struct dwc2_hsotg *hsotg)
queue_work(hsotg->wq_otg, &hsotg->wf_otg);
spin_lock(&hsotg->lock);
}
-
- /* Clear interrupt */
- dwc2_writel(GINTSTS_CONIDSTSCHNG, hsotg->regs + GINTSTS);
}
/**
@@ -315,12 +317,12 @@ static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg)
{
int ret;
- dev_dbg(hsotg->dev, "Session request interrupt - lx_state=%d\n",
- hsotg->lx_state);
-
/* Clear interrupt */
dwc2_writel(GINTSTS_SESSREQINT, hsotg->regs + GINTSTS);
+ dev_dbg(hsotg->dev, "Session request interrupt - lx_state=%d\n",
+ hsotg->lx_state);
+
if (dwc2_is_device_mode(hsotg)) {
if (hsotg->lx_state == DWC2_L2) {
ret = dwc2_exit_hibernation(hsotg, true);
@@ -347,6 +349,10 @@ static void dwc2_handle_session_req_intr(struct dwc2_hsotg *hsotg)
static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
{
int ret;
+
+ /* Clear interrupt */
+ dwc2_writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS);
+
dev_dbg(hsotg->dev, "++Resume or Remote Wakeup Detected Interrupt++\n");
dev_dbg(hsotg->dev, "%s lxstate = %d\n", __func__, hsotg->lx_state);
@@ -368,10 +374,9 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
/* Change to L0 state */
hsotg->lx_state = DWC2_L0;
} else {
- if (hsotg->core_params->hibernation) {
- dwc2_writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS);
+ if (hsotg->core_params->hibernation)
return;
- }
+
if (hsotg->lx_state != DWC2_L1) {
u32 pcgcctl = dwc2_readl(hsotg->regs + PCGCTL);
@@ -385,9 +390,6 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
hsotg->lx_state = DWC2_L0;
}
}
-
- /* Clear interrupt */
- dwc2_writel(GINTSTS_WKUPINT, hsotg->regs + GINTSTS);
}
/*
@@ -396,14 +398,14 @@ static void dwc2_handle_wakeup_detected_intr(struct dwc2_hsotg *hsotg)
*/
static void dwc2_handle_disconnect_intr(struct dwc2_hsotg *hsotg)
{
+ dwc2_writel(GINTSTS_DISCONNINT, hsotg->regs + GINTSTS);
+
dev_dbg(hsotg->dev, "++Disconnect Detected Interrupt++ (%s) %s\n",
dwc2_is_host_mode(hsotg) ? "Host" : "Device",
dwc2_op_state_str(hsotg));
if (hsotg->op_state == OTG_STATE_A_HOST)
dwc2_hcd_disconnect(hsotg);
-
- dwc2_writel(GINTSTS_DISCONNINT, hsotg->regs + GINTSTS);
}
/*
@@ -419,6 +421,9 @@ static void dwc2_handle_usb_suspend_intr(struct dwc2_hsotg *hsotg)
u32 dsts;
int ret;
+ /* Clear interrupt */
+ dwc2_writel(GINTSTS_USBSUSP, hsotg->regs + GINTSTS);
+
dev_dbg(hsotg->dev, "USB SUSPEND\n");
if (dwc2_is_device_mode(hsotg)) {
@@ -437,7 +442,7 @@ static void dwc2_handle_usb_suspend_intr(struct dwc2_hsotg *hsotg)
if (!dwc2_is_device_connected(hsotg)) {
dev_dbg(hsotg->dev,
"ignore suspend request before enumeration\n");
- goto clear_int;
+ return;
}
ret = dwc2_enter_hibernation(hsotg);
@@ -476,10 +481,6 @@ skip_power_saving:
hsotg->op_state = OTG_STATE_A_HOST;
}
}
-
-clear_int:
- /* Clear interrupt */
- dwc2_writel(GINTSTS_USBSUSP, hsotg->regs + GINTSTS);
}
#define GINTMSK_COMMON (GINTSTS_WKUPINT | GINTSTS_SESSREQINT | \
diff --git a/drivers/usb/dwc2/hcd_intr.c b/drivers/usb/dwc2/hcd_intr.c
index d965e87..955c8af 100644
--- a/drivers/usb/dwc2/hcd_intr.c
+++ b/drivers/usb/dwc2/hcd_intr.c
@@ -122,6 +122,9 @@ static void dwc2_sof_intr(struct dwc2_hsotg *hsotg)
struct dwc2_qh *qh;
enum dwc2_transaction_type tr_type;
+ /* Clear interrupt */
+ dwc2_writel(GINTSTS_SOF, hsotg->regs + GINTSTS);
+
#ifdef DEBUG_SOF
dev_vdbg(hsotg->dev, "--Start of Frame Interrupt--\n");
#endif
@@ -146,9 +149,6 @@ static void dwc2_sof_intr(struct dwc2_hsotg *hsotg)
tr_type = dwc2_hcd_select_transactions(hsotg);
if (tr_type != DWC2_TRANSACTION_NONE)
dwc2_hcd_queue_transactions(hsotg, tr_type);
-
- /* Clear interrupt */
- dwc2_writel(GINTSTS_SOF, hsotg->regs + GINTSTS);
}
/*
@@ -347,11 +347,12 @@ static void dwc2_port_intr(struct dwc2_hsotg *hsotg)
* Set flag and clear if detected
*/
if (hprt0 & HPRT0_CONNDET) {
+ writel(hprt0_modify | HPRT0_CONNDET, hsotg->regs + HPRT0);
+
dev_vdbg(hsotg->dev,
"--Port Interrupt HPRT0=0x%08x Port Connect Detected--\n",
hprt0);
dwc2_hcd_connect(hsotg);
- hprt0_modify |= HPRT0_CONNDET;
/*
* The Hub driver asserts a reset when it sees port connect
@@ -364,10 +365,10 @@ static void dwc2_port_intr(struct dwc2_hsotg *hsotg)
* Clear if detected - Set internal flag if disabled
*/
if (hprt0 & HPRT0_ENACHG) {
+ writel(hprt0_modify | HPRT0_ENACHG, hsotg->regs + HPRT0);
dev_vdbg(hsotg->dev,
" --Port Interrupt HPRT0=0x%08x Port Enable Changed (now %d)--\n",
hprt0, !!(hprt0 & HPRT0_ENA));
- hprt0_modify |= HPRT0_ENACHG;
if (hprt0 & HPRT0_ENA)
dwc2_hprt0_enable(hsotg, hprt0, &hprt0_modify);
else
@@ -376,15 +377,12 @@ static void dwc2_port_intr(struct dwc2_hsotg *hsotg)
/* Overcurrent Change Interrupt */
if (hprt0 & HPRT0_OVRCURRCHG) {
+ writel(hprt0_modify | HPRT0_OVRCURRCHG, hsotg->regs + HPRT0);
dev_vdbg(hsotg->dev,
" --Port Interrupt HPRT0=0x%08x Port Overcurrent Changed--\n",
hprt0);
hsotg->flags.b.port_over_current_change = 1;
- hprt0_modify |= HPRT0_OVRCURRCHG;
}
-
- /* Clear Port Interrupts */
- dwc2_writel(hprt0_modify, hsotg->regs + HPRT0);
}
/*
--
2.6.0.rc2.230.g3dd15c0
^ permalink raw reply [flat|nested] 4+ messages in thread* Re: [PATCH 1/2] usb: dwc2: host: Fix missing device insertions
2015-10-16 22:10 [PATCH 1/2] usb: dwc2: host: Fix missing device insertions Douglas Anderson
2015-10-16 22:10 ` [PATCH 2/2] usb: dwc2: host: Clear interrupts before handling them Douglas Anderson
@ 2015-10-30 20:38 ` John Youn
2015-11-03 20:31 ` Doug Anderson
1 sibling, 1 reply; 4+ messages in thread
From: John Youn @ 2015-10-30 20:38 UTC (permalink / raw)
To: Douglas Anderson, John Youn, balbi
Cc: Yunzhi Li, Heiko Stübner, linux-rockchip, Julius Werner,
gregory.herrero, yousaf.kaukab, dinguyen, gregkh, linux-usb,
linux-kernel
On 10/16/2015 3:10 PM, Douglas Anderson wrote:
> If you've got your interrupt signals bouncing a bit as you insert your
> USB device, you might end up in a state when the device is connected but
> the driver doesn't know it.
>
> Specifically, the observed order is:
> 1. hardware sees connect
> 2. hardware sees disconnect
> 3. hardware sees connect
> 4. dwc2_port_intr() - clears connect interrupt
> 5. dwc2_handle_common_intr() - calls dwc2_hcd_disconnect()
>
> Now you'll be stuck with the cable plugged in and no further interrupts
> coming in but the driver will think we're disconnected.
>
> We'll fix this by checking for the missing connect interrupt and
> re-connecting after the disconnect is posted. We don't skip the
> disconnect because if there is a transitory disconnect we really want to
> de-enumerate and re-enumerate.
>
> Signed-off-by: Douglas Anderson <dianders@chromium.org>
> ---
> drivers/usb/dwc2/core.h | 2 ++
> drivers/usb/dwc2/hcd.c | 33 +++++++++++++++++++++++++++++++++
> drivers/usb/dwc2/hcd_intr.c | 6 +-----
> 3 files changed, 36 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
> index ebf2504..30748be 100644
> --- a/drivers/usb/dwc2/core.h
> +++ b/drivers/usb/dwc2/core.h
> @@ -1151,11 +1151,13 @@ static inline int dwc2_hsotg_set_test_mode(struct dwc2_hsotg *hsotg,
>
> #if IS_ENABLED(CONFIG_USB_DWC2_HOST) || IS_ENABLED(CONFIG_USB_DWC2_DUAL_ROLE)
> extern int dwc2_hcd_get_frame_number(struct dwc2_hsotg *hsotg);
> +extern void dwc2_hcd_connect(struct dwc2_hsotg *hsotg);
> extern void dwc2_hcd_disconnect(struct dwc2_hsotg *hsotg);
> extern void dwc2_hcd_start(struct dwc2_hsotg *hsotg);
> #else
> static inline int dwc2_hcd_get_frame_number(struct dwc2_hsotg *hsotg)
> { return 0; }
> +static inline void dwc2_hcd_connect(struct dwc2_hsotg *hsotg) {}
> static inline void dwc2_hcd_disconnect(struct dwc2_hsotg *hsotg) {}
> static inline void dwc2_hcd_start(struct dwc2_hsotg *hsotg) {}
> static inline void dwc2_hcd_remove(struct dwc2_hsotg *hsotg) {}
> diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
> index af4e4a2..4d2bc50 100644
> --- a/drivers/usb/dwc2/hcd.c
> +++ b/drivers/usb/dwc2/hcd.c
> @@ -268,6 +268,22 @@ static void dwc2_hcd_cleanup_channels(struct dwc2_hsotg *hsotg)
> }
>
> /**
> + * dwc2_hcd_connect() - Handles connect of the HCD
> + *
> + * @hsotg: Pointer to struct dwc2_hsotg
> + *
> + * Must be called with interrupt disabled and spinlock held
> + */
> +void dwc2_hcd_connect(struct dwc2_hsotg *hsotg)
> +{
> + if (hsotg->lx_state != DWC2_L0)
> + usb_hcd_resume_root_hub(hsotg->priv);
> +
> + hsotg->flags.b.port_connect_status_change = 1;
> + hsotg->flags.b.port_connect_status = 1;
> +}
> +
> +/**
> * dwc2_hcd_disconnect() - Handles disconnect of the HCD
> *
> * @hsotg: Pointer to struct dwc2_hsotg
> @@ -277,6 +293,7 @@ static void dwc2_hcd_cleanup_channels(struct dwc2_hsotg *hsotg)
> void dwc2_hcd_disconnect(struct dwc2_hsotg *hsotg)
> {
> u32 intr;
> + u32 hprt0;
>
> /* Set status flags for the hub driver */
> hsotg->flags.b.port_connect_status_change = 1;
> @@ -315,6 +332,22 @@ void dwc2_hcd_disconnect(struct dwc2_hsotg *hsotg)
> dwc2_hcd_cleanup_channels(hsotg);
>
> dwc2_host_disconnect(hsotg);
> +
> + /*
> + * Add an extra check here to see if we're actually connected but
> + * we don't have a detection interrupt pending. This can happen if:
> + * 1. hardware sees connect
> + * 2. hardware sees disconnect
> + * 3. hardware sees connect
> + * 4. dwc2_port_intr() - clears connect interrupt
> + * 5. dwc2_handle_common_intr() - calls here
> + *
> + * Without the extra check here we will end calling disconnect
> + * and won't get any future interrupts to handle the connect.
> + */
> + hprt0 = dwc2_readl(hsotg->regs + HPRT0);
> + if (!(hprt0 & HPRT0_CONNDET) && (hprt0 & HPRT0_CONNSTS))
> + dwc2_hcd_connect(hsotg);
I'm a little bit wary of this as it will also run when you unload
the module with a device connected. However I can't produce any
negative results from that. Will it work if you handle it just
for the disconnect interrupt?
John
^ permalink raw reply [flat|nested] 4+ messages in thread