diff mbox series

usb: dwc3: debugfs: Prevent any register access when devices is runtime suspended

Message ID 20230313091837.19806-1-quic_ugoswami@quicinc.com
State Superseded
Headers show
Series usb: dwc3: debugfs: Prevent any register access when devices is runtime suspended | expand

Commit Message

Udipto Goswami March 13, 2023, 9:18 a.m. UTC 
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: Udipto Goswami <quic_ugoswami@quicinc.com>
---
 drivers/usb/dwc3/debugfs.c | 50 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)
diff mbox series

Patch

diff --git a/drivers/usb/dwc3/debugfs.c b/drivers/usb/dwc3/debugfs.c
index 850df0e6bcab..f921d4911ffc 100644
--- a/drivers/usb/dwc3/debugfs.c
+++ b/drivers/usb/dwc3/debugfs.c
@@ -544,6 +544,11 @@  static int dwc3_link_state_show(struct seq_file *s, void *unused)
 	u32			reg;
 	u8			speed;
 
+	if (pm_runtime_suspended(dwc->dev)) {
+		seq_puts(s, "Invalid operation, DWC3 suspended!");
+		return 0;
+	}
+
 	spin_lock_irqsave(&dwc->lock, flags);
 	reg = dwc3_readl(dwc->regs, DWC3_GSTS);
 	if (DWC3_GSTS_CURMOD(reg) != DWC3_GSTS_CURMOD_DEVICE) {
@@ -580,6 +585,11 @@  static ssize_t dwc3_link_state_write(struct file *file,
 	u32			reg;
 	u8			speed;
 
+	if (pm_runtime_suspended(dwc->dev)) {
+		seq_puts(s, "Invalid operation, DWC3 suspended!");
+		return 0;
+	}
+
 	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
 		return -EFAULT;
 
@@ -641,6 +651,11 @@  static int dwc3_tx_fifo_size_show(struct seq_file *s, void *unused)
 	u32			mdwidth;
 	u32			val;
 
+	if (pm_runtime_suspended(dwc->dev)) {
+		seq_puts(s, "Invalid operation, DWC3 suspended!");
+		return 0;
+	}
+
 	spin_lock_irqsave(&dwc->lock, flags);
 	val = dwc3_core_fifo_space(dep, DWC3_TXFIFO);
 
@@ -663,6 +678,11 @@  static int dwc3_rx_fifo_size_show(struct seq_file *s, void *unused)
 	u32			mdwidth;
 	u32			val;
 
+	if (pm_runtime_suspended(dwc->dev)) {
+		seq_puts(s, "Invalid operation, DWC3 suspended!");
+		return 0;
+	}
+
 	spin_lock_irqsave(&dwc->lock, flags);
 	val = dwc3_core_fifo_space(dep, DWC3_RXFIFO);
 
@@ -684,6 +704,11 @@  static int dwc3_tx_request_queue_show(struct seq_file *s, void *unused)
 	unsigned long		flags;
 	u32			val;
 
+	if (pm_runtime_suspended(dwc->dev)) {
+		seq_puts(s, "Invalid operation, DWC3 suspended!");
+		return 0;
+	}
+
 	spin_lock_irqsave(&dwc->lock, flags);
 	val = dwc3_core_fifo_space(dep, DWC3_TXREQQ);
 	seq_printf(s, "%u\n", val);
@@ -699,6 +724,11 @@  static int dwc3_rx_request_queue_show(struct seq_file *s, void *unused)
 	unsigned long		flags;
 	u32			val;
 
+	if (pm_runtime_suspended(dwc->dev)) {
+		seq_puts(s, "Invalid operation, DWC3 suspended!");
+		return 0;
+	}
+
 	spin_lock_irqsave(&dwc->lock, flags);
 	val = dwc3_core_fifo_space(dep, DWC3_RXREQQ);
 	seq_printf(s, "%u\n", val);
@@ -714,6 +744,11 @@  static int dwc3_rx_info_queue_show(struct seq_file *s, void *unused)
 	unsigned long		flags;
 	u32			val;
 
+	if (pm_runtime_suspended(dwc->dev)) {
+		seq_puts(s, "Invalid operation, DWC3 suspended!");
+		return 0;
+	}
+
 	spin_lock_irqsave(&dwc->lock, flags);
 	val = dwc3_core_fifo_space(dep, DWC3_RXINFOQ);
 	seq_printf(s, "%u\n", val);
@@ -729,6 +764,11 @@  static int dwc3_descriptor_fetch_queue_show(struct seq_file *s, void *unused)
 	unsigned long		flags;
 	u32			val;
 
+	if (pm_runtime_suspended(dwc->dev)) {
+		seq_puts(s, "Invalid operation, DWC3 suspended!");
+		return 0;
+	}
+
 	spin_lock_irqsave(&dwc->lock, flags);
 	val = dwc3_core_fifo_space(dep, DWC3_DESCFETCHQ);
 	seq_printf(s, "%u\n", val);
@@ -744,6 +784,11 @@  static int dwc3_event_queue_show(struct seq_file *s, void *unused)
 	unsigned long		flags;
 	u32			val;
 
+	if (pm_runtime_suspended(dwc->dev)) {
+		seq_puts(s, "Invalid operation, DWC3 suspended!");
+		return 0;
+	}
+
 	spin_lock_irqsave(&dwc->lock, flags);
 	val = dwc3_core_fifo_space(dep, DWC3_EVENTQ);
 	seq_printf(s, "%u\n", val);
@@ -835,6 +880,11 @@  static int dwc3_ep_info_register_show(struct seq_file *s, void *unused)
 	u32			upper_32_bits;
 	u32			reg;
 
+	if (pm_runtime_suspended(dwc->dev)) {
+		seq_puts(s, "Invalid operation, DWC3 suspended!");
+		return 0;
+	}
+
 	spin_lock_irqsave(&dwc->lock, flags);
 	reg = DWC3_GDBGLSPMUX_EPSELECT(dep->number);
 	dwc3_writel(dwc->regs, DWC3_GDBGLSPMUX, reg);