Hi,
Hauke Mehrtens <hauke@xxxxxxxxxx> writes:
> From: Rafał Miłecki <zajec5@xxxxxxxxx>
>
> This fixes problem with controller seeing devices only in some small
> percentage of cold boots.
> This quirk is also added to the platform data so we can activate it
> when we register our platform driver.
it would've been nicer if you could add an erratum ID number for future
reference together with a more verbose discussion of the problem. You're
not describing what the problem is and that's important.
> Signed-off-by: Rafał Miłecki <zajec5@xxxxxxxxx>
> Signed-off-by: Hauke Mehrtens <hauke@xxxxxxxxxx>
> ---
> drivers/usb/host/xhci-plat.c | 3 +++
> drivers/usb/host/xhci.c | 57 +++++++++++++++++++++++++++++++++++++---
> drivers/usb/host/xhci.h | 1 +
> include/linux/usb/xhci_pdriver.h | 1 +
> 4 files changed, 59 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/usb/host/xhci-plat.c b/drivers/usb/host/xhci-plat.c
> index 4fb295b..7cd274b 100644
> --- a/drivers/usb/host/xhci-plat.c
> +++ b/drivers/usb/host/xhci-plat.c
> @@ -53,6 +53,9 @@ static void xhci_plat_quirks(struct device *dev, struct xhci_hcd *xhci)
> if ((node && of_property_read_bool(node, "usb3-lpm-capable")) ||
> (pdata && pdata->usb3_lpm_capable))
> xhci->quirks |= XHCI_LPM_SUPPORT;
> +
> + if (pdata && pdata->usb3_fake_doorbell)
> + xhci->quirks |= XHCI_FAKE_DOORBELL;
whenever you add something via pdata, you _must_ make a similar DT change.
> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> index 643d312..d49be9b 100644
> --- a/drivers/usb/host/xhci.c
> +++ b/drivers/usb/host/xhci.c
> @@ -122,6 +122,39 @@ int xhci_halt(struct xhci_hcd *xhci)
> return ret;
> }
>
> +static int xhci_fake_doorbell(struct xhci_hcd *xhci, int slot_id)
> +{
> + u32 temp;
> +
> + /* alloc a virt device for slot */
> + if (!xhci_alloc_virt_device(xhci, slot_id, NULL, GFP_NOIO)) {
> + xhci_warn(xhci, "Could not allocate xHCI USB device data structures\n");
> + return -ENOMEM;
> + }
> +
> + /* ring fake doorbell for slot_id ep 0 */
> + xhci_ring_ep_doorbell(xhci, slot_id, 0, 0);
> + usleep_range(1000, 1500);
> +
> + /* read the status register to check if HSE is set or not? */
> + temp = readl(&xhci->op_regs->status);
> +
> + /* clear HSE if set */
> + if (temp & STS_FATAL) {
> + xhci_dbg(xhci, "HSE problem detected, status: 0x%x\n", temp);
> + temp &= ~(0x1fff);
> + temp |= STS_FATAL;
> + writel(temp, &xhci->op_regs->status);
> + usleep_range(1000, 1500);
> + readl(&xhci->op_regs->status);
> + }
> +
> + /* Free virt device */
> + xhci_free_virt_device(xhci, slot_id);
> +
> + return 0;
> +}
> +
> /*
> * Set the run bit and wait for the host to be running.
> */
> @@ -568,10 +601,25 @@ int xhci_init(struct usb_hcd *hcd)
>
> static int xhci_run_finished(struct xhci_hcd *xhci)
> {
> - if (xhci_start(xhci)) {
> - xhci_halt(xhci);
> - return -ENODEV;
> + int err;
> +
> + err = xhci_start(xhci);
> + if (err) {
> + err = -ENODEV;
> + goto out_err;
> + }
add a blank line here
> + if (xhci->quirks & XHCI_FAKE_DOORBELL) {
> + err = xhci_fake_doorbell(xhci, 1);
> + if (err)
> + goto out_err;
> +
> + err = xhci_start(xhci);
> + if (err) {
> + err = -ENODEV;
> + goto out_err;
> + }
> }
> +
> xhci->shared_hcd->state = HC_STATE_RUNNING;
> xhci->cmd_ring_state = CMD_RING_STATE_RUNNING;
>
> @@ -581,6 +629,9 @@ static int xhci_run_finished(struct xhci_hcd *xhci)
> xhci_dbg_trace(xhci, trace_xhci_dbg_init,
> "Finished xhci_run for USB3 roothub");
> return 0;
and another one here.
> +out_err:
> + xhci_halt(xhci);
> + return err;
> }
>
> /*
> diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h
> index 9be7348..8c1faf4 100644
> --- a/drivers/usb/host/xhci.h
> +++ b/drivers/usb/host/xhci.h
> @@ -1631,6 +1631,7 @@ struct xhci_hcd {
> #define XHCI_BROKEN_STREAMS (1 << 19)
> #define XHCI_PME_STUCK_QUIRK (1 << 20)
> #define XHCI_MTK_HOST (1 << 21)
> +#define XHCI_FAKE_DOORBELL (1 << 22)
> unsigned int num_active_eps;
> unsigned int limit_active_eps;
> /* There are two roothubs to keep track of bus suspend info for */
> diff --git a/include/linux/usb/xhci_pdriver.h b/include/linux/usb/xhci_pdriver.h
> index 376654b..2b4ea5b 100644
> --- a/include/linux/usb/xhci_pdriver.h
> +++ b/include/linux/usb/xhci_pdriver.h
> @@ -22,6 +22,7 @@
> */
> struct usb_xhci_pdata {
> unsigned usb3_lpm_capable:1;
> + unsigned usb3_fake_doorbell:1;
missing kernel doc for this new quirk.
--
balbi
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