Subject: [PATCH 2/2] ehci-mxc: bail out on transceiver problems

From: [email-masked] (Daniel Mack)
Date: Tue, 15 Jun 2010 12:43:42 +0200

On Tue, Jun 15, 2010 at 12:34:23PM +0200, Wolfram Sang wrote:
> The old code registered the hcd even if there were no transceivers
> detected, leading to oopses like this if we try to probe a non-existant
> ULPI:

Hmm. I'm aware that there was a missing bail in this function, but
actually, I had hardware which didn't properly detect the ULPI chip but
still worked fine. There has been quite some discussion here about that,
and eventually I decided to not make this a hard error as it didn't
really harm.

> [    2.730000] mxc-ehci mxc-ehci.0: unable to init transceiver
> [    2.740000] timeout polling for ULPI device
> [    2.740000] timeout polling for ULPI device
> [    2.750000] mxc-ehci mxc-ehci.0: unable to enable vbus on transceiver
> [    2.750000] mxc-ehci mxc-ehci.0: Freescale On-Chip EHCI Host Controller
> [    2.760000] mxc-ehci mxc-ehci.0: new USB bus registered, assigned bus number 2
> [    2.770000] Unhandled fault: external abort on non-linefetch (0x808) at 0xc4876184
> [    2.770000] Internal error: : 808 [#1] PREEMPT
> [    2.770000] last sysfs file:
> [    2.770000] Modules linked in:
> [    2.770000] CPU: 0    Not tainted  (2.6.33.5 #5)
> [    2.770000] PC is at ehci_hub_control+0x4d4/0x8f8
> [    2.770000] LR is at ehci_mxc_setup+0xbc/0xdc
> [    2.770000] pc : [<c0196dfc>]    lr : [<c019bc8c>]    psr: 00000093
> [    2.770000] sp : c3815e40  ip : 00000001  fp : 60000013
> [    2.770000] r10: c4876184  r9 : 00000000  r8 : c3814000
> [    2.770000] r7 : c391d2cc  r6 : 00000001  r5 : 00000001  r4 : 00000000
> [    2.770000] r3 : 80000000  r2 : 00000007  r1 : 80000000  r0 : c4876184
> [    2.770000] Flags: nzcv  IRQs off  FIQs on  Mode SVC_32  ISA ARM Segment kernel
> [    2.770000] Control: 0005317f  Table: a0004000  DAC: 00000017
> [    2.770000] Process swapper (pid: 1, stack limit = 0xc3814270)

But that, of course, changes everthing. If you happen to see such
Ooopses, your patch should go in, and I will check the boards again and
see if they still fail to probe the ULPI. Eventually, we might need some
kind of quirks field in the platform data :(

Thanks,
Daniel

> Signed-off-by: Wolfram Sang <[email-masked]>
> Cc: Sascha Hauer <[email-masked]>

Acked-by: Daniel Mack <[email-masked]>

> Cc: Greg KH <[email-masked]>
> Cc: stable at kernel.org
> ---
>  drivers/usb/host/ehci-mxc.c |   13 ++++++++++---
>  1 files changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/host/ehci-mxc.c b/drivers/usb/host/ehci-mxc.c
> index 544ccfd..bd40277 100644
> --- a/drivers/usb/host/ehci-mxc.c
> +++ b/drivers/usb/host/ehci-mxc.c
> @@ -207,10 +207,17 @@ static int ehci_mxc_drv_probe(struct platform_device *pdev)
>  	/* Initialize the transceiver */
>  	if (pdata->otg) {
>  		pdata->otg->io_priv = hcd->regs + ULPI_VIEWPORT_OFFSET;
> -		if (otg_init(pdata->otg) != 0)
> -			dev_err(dev, "unable to init transceiver\n");
> -		else if (otg_set_vbus(pdata->otg, 1) != 0)
> +		ret = otg_init(pdata->otg);
> +		if (ret) {
> +			dev_err(dev, "unable to init transceiver, probably missing\n");
> +			ret = -ENODEV;
> +			goto err_add;
> +		}
> +		ret = otg_set_vbus(pdata->otg, 1);
> +		if (ret) {
>  			dev_err(dev, "unable to enable vbus on transceiver\n");
> +			goto err_add;
> +		}
>  	}
>  
>  	priv->hcd = hcd;
> -- 
> 1.7.1
>