When the dwc3 device is runtime suspended, various required clocks would
get disabled and it is not guaranteed that access to any registers would
work. Depending on the SoC glue, a register read could be as benign as
returning 0 or be fatal enough to hang the system.
In order to prevent such scenarios of fatal errors, bail out of debugfs
function is dwc3 is suspended.
Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx>
Signed-off-by: Udipto Goswami <quic_ugoswami@xxxxxxxxxxx>
---
v4: Introduced pm_runtime_get_if_in_use in order to make sure dwc3 isn't
suspended while accessing the registers.
drivers/usb/dwc3/debugfs.c | 191 ++++++++++++++++++++++++++++++++-----
1 file changed, 169 insertions(+), 22 deletions(-)
diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
index 850df0e6bcab..e57cafb7da4b 100644
--- a/drivers/usb/dwc3/debugfs.c
+++ b/drivers/usb/dwc3/debugfs.c
@@ -543,13 +543,25 @@ static int dwc3_link_state_show(struct seq_file *s, void *unused)
enum dwc3_link_state state;
u32 reg;
u8 speed;
+ int ret = 0;
+
+ ret = pm_runtime_get_if_in_use(dwc->dev);
+ /* check if pm runtime get fails, bail out early */
+ if (ret < 0)
+ goto err_nolock;
+
+ if (!ret) {
+ ret = -EINVAL;
+ dev_err(dwc->dev,
+ "Invalid operation, DWC3 suspended!");
+ goto err_nolock;
+ }
spin_lock_irqsave(&dwc->lock, flags);
reg = dwc3_readl(dwc->regs, DWC3_GSTS);
if (DWC3_GSTS_CURMOD(reg) != DWC3_GSTS_CURMOD_DEVICE) {
seq_puts(s, "Not available\n");
- spin_unlock_irqrestore(&dwc->lock, flags);
- return 0;
+ goto err;
}
reg = dwc3_readl(dwc->regs, DWC3_DSTS);
@@ -559,9 +571,11 @@ static int dwc3_link_state_show(struct seq_file *s, void *unused)
seq_printf(s, "%s\n", (speed >= DWC3_DSTS_SUPERSPEED) ?
dwc3_gadget_link_string(state) :
dwc3_gadget_hs_link_string(state));
+err:
spin_unlock_irqrestore(&dwc->lock, flags);
-
- return 0;
+ pm_runtime_put(dwc->dev);
+err_nolock:
+ return ret;
}
static int dwc3_link_state_open(struct inode *inode, struct file *file)
@@ -579,6 +593,20 @@ static ssize_t dwc3_link_state_write(struct file *file,
char buf[32];
u32 reg;
u8 speed;
+ int ret = 0;
+
+ ret = pm_runtime_get_if_in_use(dwc->dev);
+ /* check if pm runtime get fails, bail out early */
+ if (ret < 0)
+ goto err_nolock;
+
+ if (!ret) {
+ ret = -EINVAL;
+ dev_err(dwc->dev,
+ "Invalid operation, DWC3 suspended!");
+ goto err_nolock;
+ }
+
if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
return -EFAULT;
@@ -601,8 +629,8 @@ static ssize_t dwc3_link_state_write(struct file *file,
spin_lock_irqsave(&dwc->lock, flags);
reg = dwc3_readl(dwc->regs, DWC3_GSTS);
if (DWC3_GSTS_CURMOD(reg) != DWC3_GSTS_CURMOD_DEVICE) {
- spin_unlock_irqrestore(&dwc->lock, flags);
- return -EINVAL;
+ count = -EINVAL;
+ goto err;
}
reg = dwc3_readl(dwc->regs, DWC3_DSTS);
@@ -610,13 +638,15 @@ static ssize_t dwc3_link_state_write(struct file *file,
if (speed < DWC3_DSTS_SUPERSPEED &&
state != DWC3_LINK_STATE_RECOV) {
- spin_unlock_irqrestore(&dwc->lock, flags);
- return -EINVAL;
+ count = -EINVAL;
+ goto err;
}
dwc3_gadget_set_link_state(dwc, state);
+err:
spin_unlock_irqrestore(&dwc->lock, flags);
-
+ pm_runtime_put(dwc->dev);
+err_nolock:
return count;
}
@@ -640,6 +670,19 @@ static int dwc3_tx_fifo_size_show(struct seq_file *s, void *unused)
unsigned long flags;
u32 mdwidth;
u32 val;
+ int ret = 0;
+
+ ret = pm_runtime_get_if_in_use(dwc->dev);
+ /* check if pm runtime get fails, bail out early */
+ if (ret < 0)
+ goto err_nolock;
+
+ if (!ret) {
+ ret = -EINVAL;
+ dev_err(dwc->dev,
+ "Invalid operation, DWC3 suspended!");
+ goto err_nolock;
+ }
spin_lock_irqsave(&dwc->lock, flags);
val = dwc3_core_fifo_space(dep, DWC3_TXFIFO);
@@ -650,9 +693,11 @@ static int dwc3_tx_fifo_size_show(struct seq_file *s, void *unused)
val *= mdwidth;
val >>= 3;
seq_printf(s, "%u\n", val);
- spin_unlock_irqrestore(&dwc->lock, flags);
- return 0;
+ spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put(dwc->dev);
+err_nolock:
+ return ret;
}
static int dwc3_rx_fifo_size_show(struct seq_file *s, void *unused)
@@ -662,6 +707,19 @@ static int dwc3_rx_fifo_size_show(struct seq_file *s, void *unused)
unsigned long flags;
u32 mdwidth;
u32 val;
+ int ret = 0;
+
+ ret = pm_runtime_get_if_in_use(dwc->dev);
+ /* check if pm runtime get fails, bail out early */
+ if (ret < 0)
+ goto err_nolock;
+
+ if (!ret) {
+ ret = -EINVAL;
+ dev_err(dwc->dev,
+ "Invalid operation, DWC3 suspended!");
+ goto err_nolock;
+ }
spin_lock_irqsave(&dwc->lock, flags);
val = dwc3_core_fifo_space(dep, DWC3_RXFIFO);
@@ -673,8 +731,9 @@ static int dwc3_rx_fifo_size_show(struct seq_file *s, void *unused)
val >>= 3;
seq_printf(s, "%u\n", val);
spin_unlock_irqrestore(&dwc->lock, flags);
-
- return 0;
+ pm_runtime_put(dwc->dev);
+err_nolock:
+ return ret;
}
static int dwc3_tx_request_queue_show(struct seq_file *s, void *unused)
@@ -683,13 +742,27 @@ static int dwc3_tx_request_queue_show(struct seq_file *s, void *unused)
struct dwc3 *dwc = dep->dwc;
unsigned long flags;
u32 val;
+ int ret = 0;
+
+ ret = pm_runtime_get_if_in_use(dwc->dev);
+ /* check if pm runtime get fails, bail out early */
+ if (ret < 0)
+ goto err_nolock;
+
+ if (!ret) {
+ ret = -EINVAL;
+ dev_err(dwc->dev,
+ "Invalid operation, DWC3 suspended!");
+ goto err_nolock;
+ }
spin_lock_irqsave(&dwc->lock, flags);
val = dwc3_core_fifo_space(dep, DWC3_TXREQQ);
seq_printf(s, "%u\n", val);
spin_unlock_irqrestore(&dwc->lock, flags);
-
- return 0;
+ pm_runtime_put(dwc->dev);
+err_nolock:
+ return ret;
}
static int dwc3_rx_request_queue_show(struct seq_file *s, void *unused)
@@ -698,13 +771,27 @@ static int dwc3_rx_request_queue_show(struct seq_file *s, void *unused)
struct dwc3 *dwc = dep->dwc;
unsigned long flags;
u32 val;
+ int ret = 0;
+
+ ret = pm_runtime_get_if_in_use(dwc->dev);
+ /* check if pm runtime get fails, bail out early */
+ if (ret < 0)
+ goto err_nolock;
+
+ if (!ret) {
+ ret = -EINVAL;
+ dev_err(dwc->dev,
+ "Invalid operation, DWC3 suspended!");
+ goto err_nolock;
+ }
spin_lock_irqsave(&dwc->lock, flags);
val = dwc3_core_fifo_space(dep, DWC3_RXREQQ);
seq_printf(s, "%u\n", val);
spin_unlock_irqrestore(&dwc->lock, flags);
-
- return 0;
+ pm_runtime_put(dwc->dev);
+err_nolock:
+ return ret;
}
static int dwc3_rx_info_queue_show(struct seq_file *s, void *unused)
@@ -713,13 +800,28 @@ static int dwc3_rx_info_queue_show(struct seq_file *s, void *unused)
struct dwc3 *dwc = dep->dwc;
unsigned long flags;
u32 val;
+ int ret = 0;
+
+ ret = pm_runtime_get_if_in_use(dwc->dev);
+ /* check if pm runtime get fails, bail out early */
+ if (ret < 0)
+ goto err_nolock;
+
+ if (!ret) {
+ ret = -EINVAL;
+ dev_err(dwc->dev,
+ "Invalid operation, DWC3 suspended!");
+ goto err_nolock;
+ }
spin_lock_irqsave(&dwc->lock, flags);
val = dwc3_core_fifo_space(dep, DWC3_RXINFOQ);
seq_printf(s, "%u\n", val);
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put(dwc->dev);
+err_nolock:
+ return ret;
- return 0;
}
static int dwc3_descriptor_fetch_queue_show(struct seq_file *s, void *unused)
@@ -728,13 +830,29 @@ static int dwc3_descriptor_fetch_queue_show(struct seq_file *s, void *unused)
struct dwc3 *dwc = dep->dwc;
unsigned long flags;
u32 val;
+ int ret = 0;
+
+ ret = pm_runtime_get_if_in_use(dwc->dev);
+ /* check if pm runtime get fails, bail out early */
+ if (ret < 0)
+ goto err_nolock;
+
+ if (!ret) {
+ ret = -EINVAL;
+ dev_err(dwc->dev,
+ "Invalid operation, DWC3 suspended!");
+ goto err_nolock;
+ }
spin_lock_irqsave(&dwc->lock, flags);
val = dwc3_core_fifo_space(dep, DWC3_DESCFETCHQ);
seq_printf(s, "%u\n", val);
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put(dwc->dev);
+err_nolock:
+ return ret;
+
- return 0;
}
static int dwc3_event_queue_show(struct seq_file *s, void *unused)
@@ -743,13 +861,28 @@ static int dwc3_event_queue_show(struct seq_file *s, void *unused)
struct dwc3 *dwc = dep->dwc;
unsigned long flags;
u32 val;
+ int ret = 0;
+
+ ret = pm_runtime_get_if_in_use(dwc->dev);
+ /* check if pm runtime get fails, bail out early */
+ if (ret < 0)
+ goto err_nolock;
+
+ if (!ret) {
+ ret = -EINVAL;
+ dev_err(dwc->dev,
+ "Invalid operation, DWC3 suspended!");
+ goto err_nolock;
+ }
spin_lock_irqsave(&dwc->lock, flags);
val = dwc3_core_fifo_space(dep, DWC3_EVENTQ);
seq_printf(s, "%u\n", val);
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put(dwc->dev);
+err_nolock:
+ return ret;
- return 0;
}
static int dwc3_transfer_type_show(struct seq_file *s, void *unused)
@@ -834,6 +967,19 @@ static int dwc3_ep_info_register_show(struct seq_file *s, void *unused)
u32 lower_32_bits;
u32 upper_32_bits;
u32 reg;
+ int ret = 0;
+
+ ret = pm_runtime_get_if_in_use(dwc->dev);
+ /* check if pm runtime get fails, bail out early */
+ if (ret < 0)
+ goto err_nolock;
+
+ if (!ret) {
+ ret = -EINVAL;
+ dev_err(dwc->dev,
+ "Invalid operation, DWC3 suspended!");
+ goto err_nolock;
+ }
spin_lock_irqsave(&dwc->lock, flags);
reg = DWC3_GDBGLSPMUX_EPSELECT(dep->number);
@@ -845,8 +991,9 @@ static int dwc3_ep_info_register_show(struct seq_file *s, void *unused)
ep_info = ((u64)upper_32_bits << 32) | lower_32_bits;
seq_printf(s, "0x%016llx\n", ep_info);
spin_unlock_irqrestore(&dwc->lock, flags);
-
- return 0;
+ pm_runtime_put(dwc->dev);
+err_nolock:
+ return ret;
}
DEFINE_SHOW_ATTRIBUTE(dwc3_tx_fifo_size);
--
2.17.1
