Re: [PATCH 06/25] USB: ehci: allow need_io_watchdog to be passed to ehci-platform driver

From: Florian Fainelli
Date: Wed Oct 03 2012 - 12:21:27 EST


On Wednesday 03 October 2012 12:01:22 Alan Stern wrote:
> On Wed, 3 Oct 2012, Florian Fainelli wrote:
>
> > And convert all the existing users of ehci-platform to specify a correct
> > need_io_watchdog value.
>
> IMO (and I realize that not everybody agrees), the patch description
> should not be considered an extension of the patch title, as though the
> title were the first sentence and the description the remainder of the
> same paragraph. Descriptions should stand on their own and be
> comprehensible even to somebody who hasn't read the title.
>
> > Signed-off-by: Florian Fainelli <florian@xxxxxxxxxxx>
> > ---
> > arch/mips/ath79/dev-usb.c | 2 ++
> > arch/mips/loongson1/common/platform.c | 1 +
> > arch/mips/netlogic/xlr/platform.c | 1 +
> > drivers/usb/host/bcma-hcd.c | 1 +
> > drivers/usb/host/ehci-platform.c | 1 +
> > drivers/usb/host/ssb-hcd.c | 1 +
> > include/linux/usb/ehci_pdriver.h | 3 +++
> > 7 files changed, 10 insertions(+)
>
> More importantly... Nearly every driver will have need_io_watchdog
> set. Only a few of them explicitly turn it off. The approach you're
> using puts an extra burden on most of the drivers.
>
> > diff --git a/drivers/usb/host/ehci-platform.c b/drivers/usb/host/ehci-
platform.c
> > index 764e010..08d5dec 100644
> > --- a/drivers/usb/host/ehci-platform.c
> > +++ b/drivers/usb/host/ehci-platform.c
> > @@ -32,6 +32,7 @@ static int ehci_platform_reset(struct usb_hcd *hcd)
> > ehci->has_synopsys_hc_bug = pdata->has_synopsys_hc_bug;
> > ehci->big_endian_desc = pdata->big_endian_desc;
> > ehci->big_endian_mmio = pdata->big_endian_mmio;
> > + ehci->need_io_watchdog = pdata->need_io_watchdog;
>
> > --- a/include/linux/usb/ehci_pdriver.h
> > +++ b/include/linux/usb/ehci_pdriver.h
> > @@ -29,6 +29,8 @@
> > * initialization.
> > * @port_power_off: set to 1 if the controller needs to be powered down
> > * after initialization.
> > + * @need_io_watchdog: set to 1 if the controller needs the I/O
watchdog to
> > + * run.
>
> Instead, how about adding a no_io_watchdog flag? Then after
> ehci-platform.c calls ehci_setup(), it can see whether to turn off
> ehci->need_io_watchdog.

Sounds good, you are right, this also greatly reduces the chances to miss one
user of this "feature".

>
> This way, most of this patch would become unnecessary.
>
> Alan Stern
>
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