[PATCH] Revert "usb: host: ehci: Use to USBSTS to wait for transfer completion"

[Sascha Hauer]

On Wed, Aug 12, 2020 at 10:35:59AM +0200, Christian Eggers wrote:
> Since 6044d6c08e, some USB mass storage devices (in my case some USB
> memory sticks and one SD card reader) are not detected anymore. Waiting
> once for USBSTS::USBINT is not sufficient as it takes multiple USBINT
> events until QT_TOKEN_STATUS_ACTIVE is cleared.
> 
> Fixes: 6044d6c08e ("usb: host: ehci: Use to USBSTS to wait for transfer completion")
> Signed-off-by: Christian Eggers <ceggers at arri.de>
> ---
> On Tue, Aug 11, 2020, Sascha Hauer wrote:
> > I am fine with reverting 6044d6c08e, but let's give Andrey some time to
> > react before doing this.
> 
> I'll be on holiday next week. So it send it now before it gets lost.
> 
>  drivers/usb/host/ehci-hcd.c | 21 ++++++++++++++-------
>  drivers/usb/host/ehci.h     |  1 -
>  2 files changed, 14 insertions(+), 8 deletions(-)

Applied, thanks

Sascha

> 
> diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
> index ead63b2c9f..38999927c5 100644
> --- a/drivers/usb/host/ehci-hcd.c
> +++ b/drivers/usb/host/ehci-hcd.c
> @@ -308,12 +308,14 @@ ehci_submit_async(struct usb_device *dev, unsigned long pipe, void *buffer,
>  	dma_addr_t buffer_dma, req_dma;
>  	struct QH *qh = &ehci->qh_list[1];
>  	struct qTD *td;
> +	volatile struct qTD *vtd;
>  	uint32_t *tdp;
>  	uint32_t endpt, token, usbsts;
>  	uint32_t status;
>  	uint32_t toggle;
>  	bool c;
>  	int ret;
> +	uint64_t start, timeout_val;
>  
>  
>  	dev_dbg(ehci->dev, "pipe=%lx, buffer=%p, length=%d, req=%p\n", pipe,
> @@ -442,13 +444,18 @@ ehci_submit_async(struct usb_device *dev, unsigned long pipe, void *buffer,
>  		return ret;
>  	}
>  
> -	ret = handshake(&ehci->hcor->or_usbsts, STS_USBINT, STS_USBINT,
> -			timeout_ms * 1000);
> -	if (ret < 0) {
> -		ehci_enable_async_schedule(ehci, false);
> -		ehci_writel(&qh->qt_token, 0);
> -		return -ETIMEDOUT;
> -	}
> +	/* Wait for TDs to be processed. */
> +	timeout_val = timeout_ms * MSECOND;
> +	start = get_time_ns();
> +	vtd = td;
> +	do {
> +		token = hc32_to_cpu(vtd->qt_token);
> +		if (is_timeout_non_interruptible(start, timeout_val)) {
> +			ehci_enable_async_schedule(ehci, false);
> +			ehci_writel(&qh->qt_token, 0);
> +			return -ETIMEDOUT;
> +		}
> +	} while (token & QT_TOKEN_STATUS_ACTIVE);
>  
>  	if (req)
>  		dma_unmap_single(ehci->dev, req_dma, sizeof(*req),
> diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
> index e88e37e14c..4b9092d1fe 100644
> --- a/drivers/usb/host/ehci.h
> +++ b/drivers/usb/host/ehci.h
> @@ -53,7 +53,6 @@ struct ehci_hcor {
>  #define	STD_ASS		(1 << 15)
>  #define STS_PSS         (1 << 14)
>  #define STS_HALT	(1 << 12)
> -#define STS_USBINT	BIT(0)
>  	uint32_t or_usbintr;
>  	uint32_t or_frindex;
>  	uint32_t or_ctrldssegment;
> -- 
> Christian Eggers
> Embedded software developer
> 
> Arnold & Richter Cine Technik GmbH & Co. Betriebs KG
> Sitz: Muenchen - Registergericht: Amtsgericht Muenchen - Handelsregisternummer: HRA 57918
> Persoenlich haftender Gesellschafter: Arnold & Richter Cine Technik GmbH
> Sitz: Muenchen - Registergericht: Amtsgericht Muenchen - Handelsregisternummer: HRB 54477
> Geschaeftsfuehrer: Dr. Michael Neuhaeuser; Stephan Schenk; Walter Trauninger; Markus Zeiler
> 
> 

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