This patch adds a shutdown callback to USB DWC core driver to ensure that it is properly shutdown in reboot/shutdown path. This is required where SMMU address translation is enabled like on SC7180 SoC and few others. If the hardware is still accessing memory after SMMU translation is disabled as part of SMMU shutdown callback in system reboot or shutdown path, then IOVAs(I/O virtual address) which it was using will go on the bus as the physical addresses which might result in unknown crashes (NoC/interconnect errors). Previously this was added in dwc3 qcom glue driver. https://patchwork.kernel.org/project/linux-arm-msm/list/?series=382449 But observed kernel panic as glue driver shutdown getting called after iommu shutdown. As we are adding iommu nodes in dwc core node in device tree adding shutdown callback in core driver seems correct. Signed-off-by: Sandeep Maheswaram <sanm@xxxxxxxxxxxxxx> --- drivers/usb/dwc3/core.c | 26 +++++++++++++++++++------- 1 file changed, 19 insertions(+), 7 deletions(-) diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c index 94fdbe5..777b2b5 100644 --- a/drivers/usb/dwc3/core.c +++ b/drivers/usb/dwc3/core.c @@ -1634,11 +1634,9 @@ static int dwc3_probe(struct platform_device *pdev) return ret; } -static int dwc3_remove(struct platform_device *pdev) +static void __dwc3_teardown(struct dwc3 *dwc) { - struct dwc3 *dwc = platform_get_drvdata(pdev); - - pm_runtime_get_sync(&pdev->dev); + pm_runtime_get_sync(dwc->dev); dwc3_debugfs_exit(dwc); dwc3_core_exit_mode(dwc); @@ -1646,19 +1644,32 @@ static int dwc3_remove(struct platform_device *pdev) dwc3_core_exit(dwc); dwc3_ulpi_exit(dwc); - pm_runtime_disable(&pdev->dev); - pm_runtime_put_noidle(&pdev->dev); - pm_runtime_set_suspended(&pdev->dev); + pm_runtime_disable(dwc->dev); + pm_runtime_put_noidle(dwc->dev); + pm_runtime_set_suspended(dwc->dev); dwc3_free_event_buffers(dwc); dwc3_free_scratch_buffers(dwc); if (dwc->usb_psy) power_supply_put(dwc->usb_psy); +} + +static int dwc3_remove(struct platform_device *pdev) +{ + struct dwc3 *dwc = platform_get_drvdata(pdev); + + __dwc3_teardown(dwc); return 0; } +static void dwc3_shutdown(struct platform_device *pdev) +{ + struct dwc3 *dwc = platform_get_drvdata(pdev); + + __dwc3_teardown(dwc); +} #ifdef CONFIG_PM static int dwc3_core_init_for_resume(struct dwc3 *dwc) { @@ -1976,6 +1987,7 @@ MODULE_DEVICE_TABLE(acpi, dwc3_acpi_match); static struct platform_driver dwc3_driver = { .probe = dwc3_probe, .remove = dwc3_remove, + .shutdown = dwc3_shutdown, .driver = { .name = "dwc3", .of_match_table = of_match_ptr(of_dwc3_match), -- QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
