On 3/17/2015 2:54 AM, Mian Yousaf Kaukab wrote:
> From: Gregory Herrero <gregory.herrero@xxxxxxxxx>
>
> When suspending usb bus, phy driver may disable controller power.
> In this case, registers need to be saved on suspend and restored
> on resume.
>
> Signed-off-by: Gregory Herrero <gregory.herrero@xxxxxxxxx>
> ---
> drivers/usb/dwc2/core.c | 382 ++++++++++++++++++++++++++++++++++++++++++++++++
> drivers/usb/dwc2/core.h | 84 +++++++++++
> 2 files changed, 466 insertions(+)
>
> diff --git a/drivers/usb/dwc2/core.c b/drivers/usb/dwc2/core.c
> index d5197d4..bf62d30 100644
> --- a/drivers/usb/dwc2/core.c
> +++ b/drivers/usb/dwc2/core.c
> @@ -56,6 +56,388 @@
> #include "core.h"
> #include "hcd.h"
>
> +#if IS_ENABLED(CONFIG_USB_DWC2_HOST) || IS_ENABLED(CONFIG_USB_DWC2_DUAL_ROLE)
> +/**
> + * dwc2_backup_host_registers() - Backup controller host registers.
> + * When suspending usb bus, registers needs to be backuped
> + * if controller power is disabled once suspended.
> + *
> + * @hsotg: Programming view of the DWC_otg controller
> + */
> +static int dwc2_backup_host_registers(struct dwc2_hsotg *hsotg)
> +{
> + struct dwc2_hregs_backup *hr;
> + int i;
> +
> + dev_dbg(hsotg->dev, "%s\n", __func__);
> +
> + /* Backup Host regs */
> + hr = hsotg->hr_backup;
> + if (!hr) {
> + hr = kmalloc(sizeof(*hr), GFP_KERNEL);
> + if (!hr) {
> + dev_err(hsotg->dev, "%s: can't allocate host regs\n",
> + __func__);
> + return -ENOMEM;
> + }
> +
> + hsotg->hr_backup = hr;
> + }
> + hr->hcfg = readl(hsotg->regs + HCFG);
> + hr->haintmsk = readl(hsotg->regs + HAINTMSK);
> + for (i = 0; i < hsotg->core_params->host_channels; ++i)
> + hr->hcintmsk[i] = readl(hsotg->regs + HCINTMSK(i));
> +
> + hr->hprt0 = readl(hsotg->regs + HPRT0);
> + hr->hfir = readl(hsotg->regs + HFIR);
> + return 0;
> +}
> +
> +/**
> + * dwc2_restore_host_registers() - Restore controller host registers.
> + * When resuming usb bus, device registers needs to be restored
> + * if controller power were disabled.
> + *
> + * @hsotg: Programming view of the DWC_otg controller
> + */
> +static int dwc2_restore_host_registers(struct dwc2_hsotg *hsotg)
> +{
> + struct dwc2_hregs_backup *hr;
> + int i;
> +
> + dev_dbg(hsotg->dev, "%s\n", __func__);
> +
> + /* Restore host regs */
> + hr = hsotg->hr_backup;
> + if (!hr) {
> + dev_err(hsotg->dev, "%s: no host registers to restore\n",
> + __func__);
> + return -EINVAL;
> + }
> +
> + writel(hr->hcfg, hsotg->regs + HCFG);
> + writel(hr->haintmsk, hsotg->regs + HAINTMSK);
> +
> + for (i = 0; i < hsotg->core_params->host_channels; ++i)
> + writel(hr->hcintmsk[i], hsotg->regs + HCINTMSK(i));
> +
> + writel(hr->hprt0, hsotg->regs + HPRT0);
> + writel(hr->hfir, hsotg->regs + HFIR);
> +
> + kfree(hsotg->hr_backup);
Should NULL this out otherwise you will reuse free'd memory.
Maybe better, you could just free this on remove. Just reuse the
same buffer each time.
Same with device/global registers.
John
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