Re: [PATCH v2 10/10] usb: dwc2/gadget: rework suspend/resume code to correctly restore gadget state
Hello,
On 2014-10-27 08:18, Marek Szyprowski wrote:
On 2014-10-25 03:16, Paul Zimmerman wrote:
From: Marek Szyprowski [mailto:m.szyprow...@samsung.com]
Sent: Monday, October 20, 2014 3:46 AM
Suspend/resume code assumed that the gadget was always enabled and
connected to usb bus. This means that the actual state of the gadget
(soft-enabled/disabled or connected/disconnected) was not correctly
preserved on suspend/resume cycle. This patch fixes this issue.
Signed-off-by: Marek Szyprowski m.szyprow...@samsung.com
---
drivers/usb/dwc2/core.h | 4 +++-
drivers/usb/dwc2/gadget.c | 43
+++
2 files changed, 30 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index bf015ab3b44c..3648b76a18b4 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -210,7 +210,9 @@ struct s3c_hsotg {
u8 ctrl_buff[8];
struct usb_gadget gadget;
-unsigned intsetup;
+unsigned intsetup:1;
+unsigned intconnected:1;
+unsigned intenabled:1;
unsigned long last_rst;
struct s3c_hsotg_ep *eps;
};
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 0d34cfc71bfb..c6c6cf982c90 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -2925,6 +2925,8 @@ static int s3c_hsotg_udc_start(struct
usb_gadget *gadget,
spin_lock_irqsave(hsotg-lock, flags);
s3c_hsotg_init(hsotg);
s3c_hsotg_core_init_disconnected(hsotg);
+hsotg-enabled = 1;
+hsotg-connected = 0;
spin_unlock_irqrestore(hsotg-lock, flags);
dev_info(hsotg-dev, bound driver %s\n, driver-driver.name);
@@ -2961,6 +2963,8 @@ static int s3c_hsotg_udc_stop(struct
usb_gadget *gadget,
hsotg-driver = NULL;
hsotg-gadget.speed = USB_SPEED_UNKNOWN;
+hsotg-enabled = 0;
+hsotg-connected = 0;
spin_unlock_irqrestore(hsotg-lock, flags);
@@ -2999,11 +3003,14 @@ static int s3c_hsotg_pullup(struct
usb_gadget *gadget, int is_on)
dev_dbg(hsotg-dev, %s: is_on: %d\n, __func__, is_on);
spin_lock_irqsave(hsotg-lock, flags);
+
if (is_on) {
clk_enable(hsotg-clk);
+hsotg-connected = 1;
s3c_hsotg_core_connect(hsotg);
} else {
s3c_hsotg_core_disconnect(hsotg);
+hsotg-connected = 0;
clk_disable(hsotg-clk);
}
@@ -3652,16 +3659,18 @@ static int s3c_hsotg_suspend(struct
platform_device *pdev, pm_message_t state)
dev_info(hsotg-dev, suspending usb gadget %s\n,
hsotg-driver-driver.name);
-spin_lock_irqsave(hsotg-lock, flags);
-s3c_hsotg_core_disconnect(hsotg);
-s3c_hsotg_disconnect(hsotg);
-hsotg-gadget.speed = USB_SPEED_UNKNOWN;
-spin_unlock_irqrestore(hsotg-lock, flags);
+if (hsotg-enabled) {
Hmm. Are you sure it's safe to check -enabled outside of the spinlock?
What happens if s3c_hsotg_udc_stop() runs right after this, before the
spinlock is taken, and disables stuff? Sure, it's a tiny window, but
still...
This code is called only in system suspend path, when userspace has
been already frozen.
udc_stop() can be called only as a result of userspace action, so it
is imho safe to
assume that the above code doesn't need additional locking.
However if you prefer the version with explicit locking, I will send v3
in a few minutes.
Best regards
--
Marek Szyprowski, PhD
Samsung RD Institute Poland
--
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Re: [PATCH v2 10/10] usb: dwc2/gadget: rework suspend/resume code to correctly restore gadget state
Hello,
On 2014-10-25 03:16, Paul Zimmerman wrote:
From: Marek Szyprowski [mailto:m.szyprow...@samsung.com]
Sent: Monday, October 20, 2014 3:46 AM
Suspend/resume code assumed that the gadget was always enabled and
connected to usb bus. This means that the actual state of the gadget
(soft-enabled/disabled or connected/disconnected) was not correctly
preserved on suspend/resume cycle. This patch fixes this issue.
Signed-off-by: Marek Szyprowski m.szyprow...@samsung.com
---
drivers/usb/dwc2/core.h | 4 +++-
drivers/usb/dwc2/gadget.c | 43 +++
2 files changed, 30 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index bf015ab3b44c..3648b76a18b4 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -210,7 +210,9 @@ struct s3c_hsotg {
u8 ctrl_buff[8];
struct usb_gadget gadget;
- unsigned intsetup;
+ unsigned intsetup:1;
+ unsigned intconnected:1;
+ unsigned intenabled:1;
unsigned long last_rst;
struct s3c_hsotg_ep *eps;
};
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 0d34cfc71bfb..c6c6cf982c90 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -2925,6 +2925,8 @@ static int s3c_hsotg_udc_start(struct usb_gadget *gadget,
spin_lock_irqsave(hsotg-lock, flags);
s3c_hsotg_init(hsotg);
s3c_hsotg_core_init_disconnected(hsotg);
+ hsotg-enabled = 1;
+ hsotg-connected = 0;
spin_unlock_irqrestore(hsotg-lock, flags);
dev_info(hsotg-dev, bound driver %s\n, driver-driver.name);
@@ -2961,6 +2963,8 @@ static int s3c_hsotg_udc_stop(struct usb_gadget *gadget,
hsotg-driver = NULL;
hsotg-gadget.speed = USB_SPEED_UNKNOWN;
+ hsotg-enabled = 0;
+ hsotg-connected = 0;
spin_unlock_irqrestore(hsotg-lock, flags);
@@ -2999,11 +3003,14 @@ static int s3c_hsotg_pullup(struct usb_gadget *gadget,
int is_on)
dev_dbg(hsotg-dev, %s: is_on: %d\n, __func__, is_on);
spin_lock_irqsave(hsotg-lock, flags);
+
if (is_on) {
clk_enable(hsotg-clk);
+ hsotg-connected = 1;
s3c_hsotg_core_connect(hsotg);
} else {
s3c_hsotg_core_disconnect(hsotg);
+ hsotg-connected = 0;
clk_disable(hsotg-clk);
}
@@ -3652,16 +3659,18 @@ static int s3c_hsotg_suspend(struct platform_device
*pdev, pm_message_t state)
dev_info(hsotg-dev, suspending usb gadget %s\n,
hsotg-driver-driver.name);
- spin_lock_irqsave(hsotg-lock, flags);
- s3c_hsotg_core_disconnect(hsotg);
- s3c_hsotg_disconnect(hsotg);
- hsotg-gadget.speed = USB_SPEED_UNKNOWN;
- spin_unlock_irqrestore(hsotg-lock, flags);
+ if (hsotg-enabled) {
Hmm. Are you sure it's safe to check -enabled outside of the spinlock?
What happens if s3c_hsotg_udc_stop() runs right after this, before the
spinlock is taken, and disables stuff? Sure, it's a tiny window, but
still...
This code is called only in system suspend path, when userspace has been
already frozen.
udc_stop() can be called only as a result of userspace action, so it is
imho safe to
assume that the above code doesn't need additional locking.
Best regards
--
Marek Szyprowski, PhD
Samsung RD Institute Poland
--
To unsubscribe from this list: send the line unsubscribe linux-samsung-soc in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH v2 10/10] usb: dwc2/gadget: rework suspend/resume code to correctly restore gadget state
From: Marek Szyprowski [mailto:m.szyprow...@samsung.com]
Sent: Monday, October 20, 2014 3:46 AM
Suspend/resume code assumed that the gadget was always enabled and
connected to usb bus. This means that the actual state of the gadget
(soft-enabled/disabled or connected/disconnected) was not correctly
preserved on suspend/resume cycle. This patch fixes this issue.
Signed-off-by: Marek Szyprowski m.szyprow...@samsung.com
---
drivers/usb/dwc2/core.h | 4 +++-
drivers/usb/dwc2/gadget.c | 43 +++
2 files changed, 30 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index bf015ab3b44c..3648b76a18b4 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -210,7 +210,9 @@ struct s3c_hsotg {
u8 ctrl_buff[8];
struct usb_gadget gadget;
- unsigned intsetup;
+ unsigned intsetup:1;
+ unsigned intconnected:1;
+ unsigned intenabled:1;
unsigned long last_rst;
struct s3c_hsotg_ep *eps;
};
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 0d34cfc71bfb..c6c6cf982c90 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -2925,6 +2925,8 @@ static int s3c_hsotg_udc_start(struct usb_gadget
*gadget,
spin_lock_irqsave(hsotg-lock, flags);
s3c_hsotg_init(hsotg);
s3c_hsotg_core_init_disconnected(hsotg);
+ hsotg-enabled = 1;
+ hsotg-connected = 0;
spin_unlock_irqrestore(hsotg-lock, flags);
dev_info(hsotg-dev, bound driver %s\n, driver-driver.name);
@@ -2961,6 +2963,8 @@ static int s3c_hsotg_udc_stop(struct usb_gadget *gadget,
hsotg-driver = NULL;
hsotg-gadget.speed = USB_SPEED_UNKNOWN;
+ hsotg-enabled = 0;
+ hsotg-connected = 0;
spin_unlock_irqrestore(hsotg-lock, flags);
@@ -2999,11 +3003,14 @@ static int s3c_hsotg_pullup(struct usb_gadget
*gadget, int is_on)
dev_dbg(hsotg-dev, %s: is_on: %d\n, __func__, is_on);
spin_lock_irqsave(hsotg-lock, flags);
+
if (is_on) {
clk_enable(hsotg-clk);
+ hsotg-connected = 1;
s3c_hsotg_core_connect(hsotg);
} else {
s3c_hsotg_core_disconnect(hsotg);
+ hsotg-connected = 0;
clk_disable(hsotg-clk);
}
@@ -3652,16 +3659,18 @@ static int s3c_hsotg_suspend(struct platform_device
*pdev, pm_message_t state)
dev_info(hsotg-dev, suspending usb gadget %s\n,
hsotg-driver-driver.name);
- spin_lock_irqsave(hsotg-lock, flags);
- s3c_hsotg_core_disconnect(hsotg);
- s3c_hsotg_disconnect(hsotg);
- hsotg-gadget.speed = USB_SPEED_UNKNOWN;
- spin_unlock_irqrestore(hsotg-lock, flags);
+ if (hsotg-enabled) {
Hmm. Are you sure it's safe to check -enabled outside of the spinlock?
What happens if s3c_hsotg_udc_stop() runs right after this, before the
spinlock is taken, and disables stuff? Sure, it's a tiny window, but
still...
--
Paul
+ int ep;
- s3c_hsotg_phy_disable(hsotg);
+ spin_lock_irqsave(hsotg-lock, flags);
+ if (hsotg-connected)
+ s3c_hsotg_core_disconnect(hsotg);
+ s3c_hsotg_disconnect(hsotg);
+ hsotg-gadget.speed = USB_SPEED_UNKNOWN;
+ spin_unlock_irqrestore(hsotg-lock, flags);
+
+ s3c_hsotg_phy_disable(hsotg);
- if (hsotg-driver) {
- int ep;
for (ep = 0; ep hsotg-num_of_eps; ep++)
s3c_hsotg_ep_disable(hsotg-eps[ep].ep);
@@ -3679,21 +3688,23 @@ static int s3c_hsotg_resume(struct platform_device
*pdev)
unsigned long flags;
int ret = 0;
- if (hsotg-driver) {
+ if (hsotg-driver)
dev_info(hsotg-dev, resuming usb gadget %s\n,
hsotg-driver-driver.name);
+ if (hsotg-enabled) {
clk_enable(hsotg-clk);
ret = regulator_bulk_enable(ARRAY_SIZE(hsotg-supplies),
- hsotg-supplies);
- }
+ hsotg-supplies);
- s3c_hsotg_phy_enable(hsotg);
+ s3c_hsotg_phy_enable(hsotg);
- spin_lock_irqsave(hsotg-lock, flags);
- s3c_hsotg_core_init_disconnected(hsotg);
- s3c_hsotg_core_connect(hsotg);
- spin_unlock_irqrestore(hsotg-lock, flags);
+ spin_lock_irqsave(hsotg-lock, flags);
+ s3c_hsotg_core_init_disconnected(hsotg);
+ if (hsotg-connected)
+ s3c_hsotg_core_connect(hsotg);
+ spin_unlock_irqrestore(hsotg-lock, flags);
+ }
return ret;
}
--
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[PATCH v2 10/10] usb: dwc2/gadget: rework suspend/resume code to correctly restore gadget state
Suspend/resume code assumed that the gadget was always enabled and
connected to usb bus. This means that the actual state of the gadget
(soft-enabled/disabled or connected/disconnected) was not correctly
preserved on suspend/resume cycle. This patch fixes this issue.
Signed-off-by: Marek Szyprowski m.szyprow...@samsung.com
---
drivers/usb/dwc2/core.h | 4 +++-
drivers/usb/dwc2/gadget.c | 43 +++
2 files changed, 30 insertions(+), 17 deletions(-)
diff --git a/drivers/usb/dwc2/core.h b/drivers/usb/dwc2/core.h
index bf015ab3b44c..3648b76a18b4 100644
--- a/drivers/usb/dwc2/core.h
+++ b/drivers/usb/dwc2/core.h
@@ -210,7 +210,9 @@ struct s3c_hsotg {
u8 ctrl_buff[8];
struct usb_gadget gadget;
- unsigned intsetup;
+ unsigned intsetup:1;
+ unsigned intconnected:1;
+ unsigned intenabled:1;
unsigned long last_rst;
struct s3c_hsotg_ep *eps;
};
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 0d34cfc71bfb..c6c6cf982c90 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -2925,6 +2925,8 @@ static int s3c_hsotg_udc_start(struct usb_gadget *gadget,
spin_lock_irqsave(hsotg-lock, flags);
s3c_hsotg_init(hsotg);
s3c_hsotg_core_init_disconnected(hsotg);
+ hsotg-enabled = 1;
+ hsotg-connected = 0;
spin_unlock_irqrestore(hsotg-lock, flags);
dev_info(hsotg-dev, bound driver %s\n, driver-driver.name);
@@ -2961,6 +2963,8 @@ static int s3c_hsotg_udc_stop(struct usb_gadget *gadget,
hsotg-driver = NULL;
hsotg-gadget.speed = USB_SPEED_UNKNOWN;
+ hsotg-enabled = 0;
+ hsotg-connected = 0;
spin_unlock_irqrestore(hsotg-lock, flags);
@@ -2999,11 +3003,14 @@ static int s3c_hsotg_pullup(struct usb_gadget *gadget,
int is_on)
dev_dbg(hsotg-dev, %s: is_on: %d\n, __func__, is_on);
spin_lock_irqsave(hsotg-lock, flags);
+
if (is_on) {
clk_enable(hsotg-clk);
+ hsotg-connected = 1;
s3c_hsotg_core_connect(hsotg);
} else {
s3c_hsotg_core_disconnect(hsotg);
+ hsotg-connected = 0;
clk_disable(hsotg-clk);
}
@@ -3652,16 +3659,18 @@ static int s3c_hsotg_suspend(struct platform_device
*pdev, pm_message_t state)
dev_info(hsotg-dev, suspending usb gadget %s\n,
hsotg-driver-driver.name);
- spin_lock_irqsave(hsotg-lock, flags);
- s3c_hsotg_core_disconnect(hsotg);
- s3c_hsotg_disconnect(hsotg);
- hsotg-gadget.speed = USB_SPEED_UNKNOWN;
- spin_unlock_irqrestore(hsotg-lock, flags);
+ if (hsotg-enabled) {
+ int ep;
- s3c_hsotg_phy_disable(hsotg);
+ spin_lock_irqsave(hsotg-lock, flags);
+ if (hsotg-connected)
+ s3c_hsotg_core_disconnect(hsotg);
+ s3c_hsotg_disconnect(hsotg);
+ hsotg-gadget.speed = USB_SPEED_UNKNOWN;
+ spin_unlock_irqrestore(hsotg-lock, flags);
+
+ s3c_hsotg_phy_disable(hsotg);
- if (hsotg-driver) {
- int ep;
for (ep = 0; ep hsotg-num_of_eps; ep++)
s3c_hsotg_ep_disable(hsotg-eps[ep].ep);
@@ -3679,21 +3688,23 @@ static int s3c_hsotg_resume(struct platform_device
*pdev)
unsigned long flags;
int ret = 0;
- if (hsotg-driver) {
+ if (hsotg-driver)
dev_info(hsotg-dev, resuming usb gadget %s\n,
hsotg-driver-driver.name);
+ if (hsotg-enabled) {
clk_enable(hsotg-clk);
ret = regulator_bulk_enable(ARRAY_SIZE(hsotg-supplies),
- hsotg-supplies);
- }
+ hsotg-supplies);
- s3c_hsotg_phy_enable(hsotg);
+ s3c_hsotg_phy_enable(hsotg);
- spin_lock_irqsave(hsotg-lock, flags);
- s3c_hsotg_core_init_disconnected(hsotg);
- s3c_hsotg_core_connect(hsotg);
- spin_unlock_irqrestore(hsotg-lock, flags);
+ spin_lock_irqsave(hsotg-lock, flags);
+ s3c_hsotg_core_init_disconnected(hsotg);
+ if (hsotg-connected)
+ s3c_hsotg_core_connect(hsotg);
+ spin_unlock_irqrestore(hsotg-lock, flags);
+ }
return ret;
}
--
1.9.2
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