[PATCH 5.4 084/161] usb: dwc3: debugfs: Resume dwc3 before accessing registers

From: Udipto Goswami quic_ugoswami@quicinc.com

commit 614ce6a2ea50068b45339257891e51e639ac9001 upstream.

When the dwc3 device is runtime suspended, various required clocks are in disabled state 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.

Fixes: 72246da40f37 ("usb: Introduce DesignWare USB3 DRD Driver") Cc: stable@vger.kernel.org #3.2: 30332eeefec8: debugfs: regset32: Add Runtime PM support Signed-off-by: Udipto Goswami quic_ugoswami@quicinc.com Reviewed-by: Johan Hovold johan+linaro@kernel.org Tested-by: Johan Hovold johan+linaro@kernel.org Acked-by: Thinh Nguyen Thinh.Nguyen@synopsys.com Link: https://lore.kernel.org/r/20230509144836.6803-1-quic_ugoswami@quicinc.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/dwc3/debugfs.c | 109 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 109 insertions(+)

--- a/drivers/usb/dwc3/debugfs.c +++ b/drivers/usb/dwc3/debugfs.c @@ -327,6 +327,11 @@ static int dwc3_lsp_show(struct seq_file unsigned int current_mode; unsigned long flags; u32 reg; + int ret; + + ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret;

spin_lock_irqsave(&dwc->lock, flags); reg = dwc3_readl(dwc->regs, DWC3_GSTS); @@ -345,6 +350,8 @@ static int dwc3_lsp_show(struct seq_file } spin_unlock_irqrestore(&dwc->lock, flags);

+ pm_runtime_put_sync(dwc->dev); + return 0; }

@@ -390,6 +397,11 @@ static int dwc3_mode_show(struct seq_fil struct dwc3 *dwc = s->private; unsigned long flags; u32 reg; + int ret; + + ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret;

spin_lock_irqsave(&dwc->lock, flags); reg = dwc3_readl(dwc->regs, DWC3_GCTL); @@ -409,6 +421,8 @@ static int dwc3_mode_show(struct seq_fil seq_printf(s, "UNKNOWN %08x\n", DWC3_GCTL_PRTCAP(reg)); }

+ pm_runtime_put_sync(dwc->dev); + return 0; }

@@ -455,6 +469,11 @@ static int dwc3_testmode_show(struct seq struct dwc3 *dwc = s->private; unsigned long flags; u32 reg; + int ret; + + ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret;

spin_lock_irqsave(&dwc->lock, flags); reg = dwc3_readl(dwc->regs, DWC3_DCTL); @@ -485,6 +504,8 @@ static int dwc3_testmode_show(struct seq seq_printf(s, "UNKNOWN %d\n", reg); }

+ pm_runtime_put_sync(dwc->dev); + return 0; }

@@ -501,6 +522,7 @@ static ssize_t dwc3_testmode_write(struc 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; @@ -518,10 +540,16 @@ static ssize_t dwc3_testmode_write(struc else testmode = 0;

+ ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret; + spin_lock_irqsave(&dwc->lock, flags); dwc3_gadget_set_test_mode(dwc, testmode); spin_unlock_irqrestore(&dwc->lock, flags);

+ pm_runtime_put_sync(dwc->dev); + return count; }

@@ -540,12 +568,18 @@ static int dwc3_link_state_show(struct s enum dwc3_link_state state; u32 reg; u8 speed; + int ret; + + ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret;

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_sync(dwc->dev); return 0; }

@@ -558,6 +592,8 @@ static int dwc3_link_state_show(struct s dwc3_gadget_hs_link_string(state)); spin_unlock_irqrestore(&dwc->lock, flags);

+ pm_runtime_put_sync(dwc->dev); + return 0; }

@@ -576,6 +612,7 @@ static ssize_t dwc3_link_state_write(str 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; @@ -595,10 +632,15 @@ static ssize_t dwc3_link_state_write(str else return -EINVAL;

+ ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret; + 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_sync(dwc->dev); return -EINVAL; }

@@ -608,12 +650,15 @@ static ssize_t dwc3_link_state_write(str if (speed < DWC3_DSTS_SUPERSPEED && state != DWC3_LINK_STATE_RECOV) { spin_unlock_irqrestore(&dwc->lock, flags); + pm_runtime_put_sync(dwc->dev); return -EINVAL; }

dwc3_gadget_set_link_state(dwc, state); spin_unlock_irqrestore(&dwc->lock, flags);

+ pm_runtime_put_sync(dwc->dev); + return count; }

@@ -636,6 +681,11 @@ static int dwc3_tx_fifo_size_show(struct struct dwc3 *dwc = dep->dwc; unsigned long flags; u32 val; + int ret; + + ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret;

spin_lock_irqsave(&dwc->lock, flags); val = dwc3_core_fifo_space(dep, DWC3_TXFIFO); @@ -646,6 +696,8 @@ static int dwc3_tx_fifo_size_show(struct seq_printf(s, "%u\n", val); spin_unlock_irqrestore(&dwc->lock, flags);

+ pm_runtime_put_sync(dwc->dev); + return 0; }

@@ -655,6 +707,11 @@ static int dwc3_rx_fifo_size_show(struct struct dwc3 *dwc = dep->dwc; unsigned long flags; u32 val; + int ret; + + ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret;

spin_lock_irqsave(&dwc->lock, flags); val = dwc3_core_fifo_space(dep, DWC3_RXFIFO); @@ -665,6 +722,8 @@ static int dwc3_rx_fifo_size_show(struct seq_printf(s, "%u\n", val); spin_unlock_irqrestore(&dwc->lock, flags);

+ pm_runtime_put_sync(dwc->dev); + return 0; }

@@ -674,12 +733,19 @@ static int dwc3_tx_request_queue_show(st struct dwc3 *dwc = dep->dwc; unsigned long flags; u32 val; + int ret; + + ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret;

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_sync(dwc->dev); + return 0; }

@@ -689,12 +755,19 @@ static int dwc3_rx_request_queue_show(st struct dwc3 *dwc = dep->dwc; unsigned long flags; u32 val; + int ret; + + ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret;

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_sync(dwc->dev); + return 0; }

@@ -704,12 +777,19 @@ static int dwc3_rx_info_queue_show(struc struct dwc3 *dwc = dep->dwc; unsigned long flags; u32 val; + int ret; + + ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret;

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_sync(dwc->dev); + return 0; }

@@ -719,12 +799,19 @@ static int dwc3_descriptor_fetch_queue_s struct dwc3 *dwc = dep->dwc; unsigned long flags; u32 val; + int ret; + + ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret;

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_sync(dwc->dev); + return 0; }

@@ -734,12 +821,19 @@ static int dwc3_event_queue_show(struct struct dwc3 *dwc = dep->dwc; unsigned long flags; u32 val; + int ret; + + ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret;

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_sync(dwc->dev); + return 0; }

@@ -785,6 +879,11 @@ static int dwc3_trb_ring_show(struct seq struct dwc3 *dwc = dep->dwc; unsigned long flags; int i; + int ret; + + ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret;

spin_lock_irqsave(&dwc->lock, flags); if (dep->number <= 1) { @@ -814,6 +913,8 @@ static int dwc3_trb_ring_show(struct seq out: spin_unlock_irqrestore(&dwc->lock, flags);

+ pm_runtime_put_sync(dwc->dev); + return 0; }

@@ -826,6 +927,11 @@ static int dwc3_ep_info_register_show(st u32 lower_32_bits; u32 upper_32_bits; u32 reg; + int ret; + + ret = pm_runtime_resume_and_get(dwc->dev); + if (ret < 0) + return ret;

spin_lock_irqsave(&dwc->lock, flags); reg = DWC3_GDBGLSPMUX_EPSELECT(dep->number); @@ -838,6 +944,8 @@ static int dwc3_ep_info_register_show(st seq_printf(s, "0x%016llx\n", ep_info); spin_unlock_irqrestore(&dwc->lock, flags);

+ pm_runtime_put_sync(dwc->dev); + return 0; }

@@ -899,6 +1007,7 @@ 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), NULL); dwc->root = root;