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, make sure to resume
dwc3 then allow the function to proceed.
Signed-off-by: Udipto Goswami <quic_ugoswami@xxxxxxxxxxx>
---
v6: Added changes to handle get_dync failure appropriately.
v5: Reworked the patch to resume dwc3 while accessing the registers.
v4: Introduced pm_runtime_get_if_in_use in order to make sure dwc3 isn't
suspended while accessing the registers.
v3: Replace pr_err to dev_err.
v2: Replaced return 0 with -EINVAL & seq_puts with pr_err.
drivers/usb/dwc3/debugfs.c | 124 +++++++++++++++++++++++++++++++++++++
1 file changed, 124 insertions(+)
diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
index e4a2560b9dc0..b08604a73e69 100644
--- a/drivers/usb/dwc3/debugfs.c
+++ b/drivers/usb/dwc3/debugfs.c
@@ -332,6 +332,13 @@ static int dwc3_lsp_show(struct seq_file *s, void *unused)
unsigned int current_mode;
unsigned long flags;
u32 reg;
+ int ret;
+
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
spin_lock_irqsave(&dwc->lock, flags);
reg = dwc3_readl(dwc->regs, DWC3_GSTS);
@@ -349,6 +356,7 @@ static int dwc3_lsp_show(struct seq_file *s, void *unused)
break;
}
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put(dwc->dev);
return 0;
}
@@ -395,6 +403,13 @@ static int dwc3_mode_show(struct seq_file *s, void *unused)
struct dwc3 *dwc = s->private;
unsigned long flags;
u32 reg;
+ int ret;
+
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
spin_lock_irqsave(&dwc->lock, flags);
reg = dwc3_readl(dwc->regs, DWC3_GCTL);
@@ -414,6 +429,7 @@ static int dwc3_mode_show(struct seq_file *s, void *unused)
seq_printf(s, "UNKNOWN %08x\n", DWC3_GCTL_PRTCAP(reg));
}
+ pm_runtime_put(dwc->dev);
return 0;
}
@@ -463,6 +479,13 @@ static int dwc3_testmode_show(struct seq_file *s, void *unused)
struct dwc3 *dwc = s->private;
unsigned long flags;
u32 reg;
+ int ret;
+
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
spin_lock_irqsave(&dwc->lock, flags);
reg = dwc3_readl(dwc->regs, DWC3_DCTL);
@@ -493,6 +516,7 @@ static int dwc3_testmode_show(struct seq_file *s, void *unused)
seq_printf(s, "UNKNOWN %d\n", reg);
}
+ pm_runtime_put(dwc->dev);
return 0;
}
@@ -509,6 +533,7 @@ static ssize_t dwc3_testmode_write(struct file *file,
unsigned long flags;
u32 testmode = 0;
char buf[32];
+ int ret;
if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
return -EFAULT;
@@ -526,10 +551,17 @@ static ssize_t dwc3_testmode_write(struct file *file,
else
testmode = 0;
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
+
spin_lock_irqsave(&dwc->lock, flags);
dwc3_gadget_set_test_mode(dwc, testmode);
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put(dwc->dev);
return count;
}
@@ -548,12 +580,20 @@ static int dwc3_link_state_show(struct seq_file *s, void *unused)
enum dwc3_link_state state;
u32 reg;
u8 speed;
+ int ret;
+
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
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);
+ pm_runtime_put(dwc->dev);
return 0;
}
@@ -566,6 +606,7 @@ static int dwc3_link_state_show(struct seq_file *s, void *unused)
dwc3_gadget_hs_link_string(state));
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put(dwc->dev);
return 0;
}
@@ -584,6 +625,7 @@ static ssize_t dwc3_link_state_write(struct file *file,
char buf[32];
u32 reg;
u8 speed;
+ int ret;
if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
return -EFAULT;
@@ -603,10 +645,17 @@ static ssize_t dwc3_link_state_write(struct file *file,
else
return -EINVAL;
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
+
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);
+ pm_runtime_put(dwc->dev);
return -EINVAL;
}
@@ -616,12 +665,14 @@ 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);
+ pm_runtime_put(dwc->dev);
return -EINVAL;
}
dwc3_gadget_set_link_state(dwc, state);
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put(dwc->dev);
return count;
}
@@ -645,6 +696,13 @@ static int dwc3_tx_fifo_size_show(struct seq_file *s, void *unused)
unsigned long flags;
u32 mdwidth;
u32 val;
+ int ret;
+
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
spin_lock_irqsave(&dwc->lock, flags);
val = dwc3_core_fifo_space(dep, DWC3_TXFIFO);
@@ -657,6 +715,7 @@ static int dwc3_tx_fifo_size_show(struct seq_file *s, void *unused)
seq_printf(s, "%u\n", val);
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put(dwc->dev);
return 0;
}
@@ -667,6 +726,13 @@ static int dwc3_rx_fifo_size_show(struct seq_file *s, void *unused)
unsigned long flags;
u32 mdwidth;
u32 val;
+ int ret;
+
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
spin_lock_irqsave(&dwc->lock, flags);
val = dwc3_core_fifo_space(dep, DWC3_RXFIFO);
@@ -679,6 +745,7 @@ static int dwc3_rx_fifo_size_show(struct seq_file *s, void *unused)
seq_printf(s, "%u\n", val);
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put(dwc->dev);
return 0;
}
@@ -688,12 +755,20 @@ 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;
+
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
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);
+ pm_runtime_put(dwc->dev);
return 0;
}
@@ -703,12 +778,20 @@ 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;
+
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
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);
+ pm_runtime_put(dwc->dev);
return 0;
}
@@ -718,12 +801,20 @@ 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;
+
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
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);
return 0;
}
@@ -733,12 +824,20 @@ 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;
+
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
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);
return 0;
}
@@ -748,12 +847,20 @@ static int dwc3_event_queue_show(struct seq_file *s, void *unused)
struct dwc3 *dwc = dep->dwc;
unsigned long flags;
u32 val;
+ int ret;
+
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
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);
return 0;
}
@@ -798,6 +905,13 @@ static int dwc3_trb_ring_show(struct seq_file *s, void *unused)
struct dwc3 *dwc = dep->dwc;
unsigned long flags;
int i;
+ int ret;
+
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
spin_lock_irqsave(&dwc->lock, flags);
if (dep->number <= 1) {
@@ -827,6 +941,7 @@ static int dwc3_trb_ring_show(struct seq_file *s, void *unused)
out:
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put(dwc->dev);
return 0;
}
@@ -839,6 +954,13 @@ 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;
+
+ ret = pm_runtime_get_sync(dwc->dev);
+ if (ret < 0) {
+ pm_runtime_put(dwc->dev);
+ return -EINVAL;
+ }
spin_lock_irqsave(&dwc->lock, flags);
reg = DWC3_GDBGLSPMUX_EPSELECT(dep->number);
@@ -851,6 +973,7 @@ static int dwc3_ep_info_register_show(struct seq_file *s, void *unused)
seq_printf(s, "0x%016llx\n", ep_info);
spin_unlock_irqrestore(&dwc->lock, flags);
+ pm_runtime_put(dwc->dev);
return 0;
}
@@ -910,6 +1033,7 @@ void dwc3_debugfs_init(struct dwc3 *dwc)
dwc->regset->regs = dwc3_regs;
dwc->regset->nregs = ARRAY_SIZE(dwc3_regs);
dwc->regset->base = dwc->regs - DWC3_GLOBALS_REGS_START;
+ dwc->regset->dev = dwc->dev;
root = debugfs_create_dir(dev_name(dwc->dev), usb_debug_root);
dwc->debug_root = root;
--
2.17.1
