RE: [PATCH] usb: dwc3: Keeping 'resource' related code together

From: Paul Zimmerman
Date: Tue Jun 03 2014 - 15:12:05 EST


> From: linux-usb-owner@xxxxxxxxxxxxxxx [mailto:linux-usb-owner@xxxxxxxxxxxxxxx] On Behalf Of Vivek Gautam
> Sent: Tuesday, June 03, 2014 3:40 AM
>
> Putting together the code related to getting the 'IORESOURCE_MEM'
> and assigning the same to dwc->xhci_resources, for increasing
> the readability.
>
> Signed-off-by: Vivek Gautam <gautam.vivek@xxxxxxxxxxx>
> ---
>
> Based on 'next' branch of Felipe's usb tree.
> Also cleanly applies to 'usb-next' branch of Greg's usb tree.
>
> drivers/usb/dwc3/core.c | 38 +++++++++++++++++++-------------------
> 1 file changed, 19 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 3f59c12..4ca925d 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -656,6 +656,25 @@ static int dwc3_probe(struct platform_device *pdev)
> return -ENODEV;
> }
>
> + dwc->xhci_resources[0].start = res->start;
> + dwc->xhci_resources[0].end = dwc->xhci_resources[0].start +
> + DWC3_XHCI_REGS_END;
> + dwc->xhci_resources[0].flags = res->flags;
> + dwc->xhci_resources[0].name = res->name;
> +
> + res->start += DWC3_GLOBALS_REGS_START;
> +
> + /*
> + * Request memory region but exclude xHCI regs,
> + * since it will be requested by the xhci-plat driver.
> + */
> + regs = devm_ioremap_resource(dev, res);
> + if (IS_ERR(regs))
> + return PTR_ERR(regs);
> +
> + dwc->regs = regs;
> + dwc->regs_size = resource_size(res);
> +
> if (node) {
> dwc->maximum_speed = of_usb_get_maximum_speed(node);

I think this will break if the following dwc3_core_get_phy() call returns
-EPROBE_DEFER. Since you have incremented res->start above, the next time
this probe function is called, res->start will have the wrong value.
Provided I'm reading the code correctly of course :)

I think you could fix that by decrementing res->start back to its
original value just after the call to resource_size() above.

--
Paul

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