USB: dwc3: drop dead hibernation code

The hibernation code is broken and has never been enabled in mainline
and should thus be dropped.

Specifically, the scratch buffer DMA mapping would have been leaked on
every suspend cycle since commit 51f5d49ad6f0 ("usb: dwc3: core:
simplify suspend/resume operations") if this feature was ever enabled.

The related error handling was also broken and could have resulted in
attempts to unmap never mapped buffers, etc.

This effectively revert commit 0ffcaf3798bf ("usb: dwc3: core: allocate
scratch buffers").

Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20230404072524.19014-6-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 1 insertions, 102 deletions

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index bb737c3bd58a..4ed98855bf64 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -534,90 +534,6 @@ void dwc3_event_buffers_cleanup(struct dwc3 *dwc)
 	dwc3_writel(dwc->regs, DWC3_GEVNTCOUNT(0), 0);
 }
 
-static int dwc3_alloc_scratch_buffers(struct dwc3 *dwc)
-{
-	if (!dwc->has_hibernation)
-		return 0;
-
-	if (!dwc->nr_scratch)
-		return 0;
-
-	dwc->scratchbuf = kmalloc_array(dwc->nr_scratch,
-			DWC3_SCRATCHBUF_SIZE, GFP_KERNEL);
-	if (!dwc->scratchbuf)
-		return -ENOMEM;
-
-	return 0;
-}
-
-static int dwc3_setup_scratch_buffers(struct dwc3 *dwc)
-{
-	dma_addr_t scratch_addr;
-	u32 param;
-	int ret;
-
-	if (!dwc->has_hibernation)
-		return 0;
-
-	if (!dwc->nr_scratch)
-		return 0;
-
-	 /* should never fall here */
-	if (!WARN_ON(dwc->scratchbuf))
-		return 0;
-
-	scratch_addr = dma_map_single(dwc->sysdev, dwc->scratchbuf,
-			dwc->nr_scratch * DWC3_SCRATCHBUF_SIZE,
-			DMA_BIDIRECTIONAL);
-	if (dma_mapping_error(dwc->sysdev, scratch_addr)) {
-		dev_err(dwc->sysdev, "failed to map scratch buffer\n");
-		ret = -EFAULT;
-		goto err0;
-	}
-
-	dwc->scratch_addr = scratch_addr;
-
-	param = lower_32_bits(scratch_addr);
-
-	ret = dwc3_send_gadget_generic_command(dwc,
-			DWC3_DGCMD_SET_SCRATCHPAD_ADDR_LO, param);
-	if (ret < 0)
-		goto err1;
-
-	param = upper_32_bits(scratch_addr);
-
-	ret = dwc3_send_gadget_generic_command(dwc,
-			DWC3_DGCMD_SET_SCRATCHPAD_ADDR_HI, param);
-	if (ret < 0)
-		goto err1;
-
-	return 0;
-
-err1:
-	dma_unmap_single(dwc->sysdev, dwc->scratch_addr, dwc->nr_scratch *
-			DWC3_SCRATCHBUF_SIZE, DMA_BIDIRECTIONAL);
-
-err0:
-	return ret;
-}
-
-static void dwc3_free_scratch_buffers(struct dwc3 *dwc)
-{
-	if (!dwc->has_hibernation)
-		return;
-
-	if (!dwc->nr_scratch)
-		return;
-
-	 /* should never fall here */
-	if (!WARN_ON(dwc->scratchbuf))
-		return;
-
-	dma_unmap_single(dwc->sysdev, dwc->scratch_addr, dwc->nr_scratch *
-			DWC3_SCRATCHBUF_SIZE, DMA_BIDIRECTIONAL);
-	kfree(dwc->scratchbuf);
-}
-
 static void dwc3_core_num_eps(struct dwc3 *dwc)
 {
 	struct dwc3_hwparams	*parms = &dwc->hwparams;
@@ -887,7 +803,6 @@ static bool dwc3_core_is_valid(struct dwc3 *dwc)
 
 static void dwc3_core_setup_global_control(struct dwc3 *dwc)
 {
-	u32 hwparams4 = dwc->hwparams.hwparams4;
 	u32 reg;
 
 	reg = dwc3_readl(dwc->regs, DWC3_GCTL);
@@ -915,9 +830,6 @@ static void dwc3_core_setup_global_control(struct dwc3 *dwc)
 			reg &= ~DWC3_GCTL_DSBLCLKGTNG;
 		break;
 	case DWC3_GHWPARAMS1_EN_PWROPT_HIB:
-		/* enable hibernation here */
-		dwc->nr_scratch = DWC3_GHWPARAMS4_HIBER_SCRATCHBUFS(hwparams4);
-
 		/*
 		 * REVISIT Enabling this bit so that host-mode hibernation
 		 * will work. Device-mode hibernation is not yet implemented.
@@ -1161,10 +1073,6 @@ static int dwc3_core_init(struct dwc3 *dwc)
 	dwc3_core_setup_global_control(dwc);
 	dwc3_core_num_eps(dwc);
 
-	ret = dwc3_setup_scratch_buffers(dwc);
-	if (ret)
-		goto err1;
-
 	/* Set power down scale of suspend_clk */
 	dwc3_set_power_down_clk_scale(dwc);
 
@@ -1920,14 +1828,10 @@ static int dwc3_probe(struct platform_device *pdev)
 	if (ret)
 		goto err3;
 
-	ret = dwc3_alloc_scratch_buffers(dwc);
-	if (ret)
-		goto err3;
-
 	ret = dwc3_core_init(dwc);
 	if (ret) {
 		dev_err_probe(dev, ret, "failed to initialize core\n");
-		goto err4;
+		goto err3;
 	}
 
 	dwc3_check_params(dwc);
@@ -1956,10 +1860,6 @@ err5:
 	phy_exit(dwc->usb3_generic_phy);
 
 	dwc3_ulpi_exit(dwc);
-
-err4:
-	dwc3_free_scratch_buffers(dwc);
-
 err3:
 	dwc3_free_event_buffers(dwc);
 
@@ -1999,7 +1899,6 @@ static int dwc3_remove(struct platform_device *pdev)
 	pm_runtime_set_suspended(&pdev->dev);
 
 	dwc3_free_event_buffers(dwc);
-	dwc3_free_scratch_buffers(dwc);
 
 	if (dwc->usb_psy)
 		power_supply_put(dwc->usb_psy);