Commit ec1f9d9f01384 ("usb: dwc2: gadget: parity fix in isochronous mode") moved
these checks to dwc2_hsotg_change_ep_iso_parity() back in 2015. The assigned
value hasn't been read back since. Let's remove the unnecessary H/W read.
Fixes the following W=1 warning:
drivers/usb/dwc2/gadget.c: In function ‘dwc2_hsotg_epint’:
drivers/usb/dwc2/gadget.c:2981:6: warning: variable ‘ctrl’ set but not used [-Wunused-but-set-variable]
2981 | u32 ctrl;
| ^~~~
Cc: Minas Harutyunyan <[email protected]>
Cc: Ben Dooks <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
---
drivers/usb/dwc2/gadget.c | 2 --
1 file changed, 2 deletions(-)
diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 116e6175c7a48..fa07e3fcb8841 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -2975,10 +2975,8 @@ static void dwc2_hsotg_epint(struct dwc2_hsotg *hsotg, unsigned int idx,
u32 epctl_reg = dir_in ? DIEPCTL(idx) : DOEPCTL(idx);
u32 epsiz_reg = dir_in ? DIEPTSIZ(idx) : DOEPTSIZ(idx);
u32 ints;
- u32 ctrl;
ints = dwc2_gadget_read_ep_interrupts(hsotg, idx, dir_in);
- ctrl = dwc2_readl(hsotg, epctl_reg);
/* Clear endpoint interrupts */
dwc2_writel(hsotg, ints, epint_reg);
--
2.25.1
On Thu, Jul 02, 2020 at 03:46:06PM +0100, Lee Jones wrote:
> Commit ec1f9d9f01384 ("usb: dwc2: gadget: parity fix in isochronous mode") moved
> these checks to dwc2_hsotg_change_ep_iso_parity() back in 2015. The assigned
> value hasn't been read back since. Let's remove the unnecessary H/W read.
>
> Fixes the following W=1 warning:
>
> drivers/usb/dwc2/gadget.c: In function ‘dwc2_hsotg_epint’:
> drivers/usb/dwc2/gadget.c:2981:6: warning: variable ‘ctrl’ set but not used [-Wunused-but-set-variable]
> 2981 | u32 ctrl;
> | ^~~~
>
> Cc: Minas Harutyunyan <[email protected]>
> Cc: Ben Dooks <[email protected]>
> Signed-off-by: Lee Jones <[email protected]>
> ---
> drivers/usb/dwc2/gadget.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> index 116e6175c7a48..fa07e3fcb8841 100644
> --- a/drivers/usb/dwc2/gadget.c
> +++ b/drivers/usb/dwc2/gadget.c
> @@ -2975,10 +2975,8 @@ static void dwc2_hsotg_epint(struct dwc2_hsotg *hsotg, unsigned int idx,
> u32 epctl_reg = dir_in ? DIEPCTL(idx) : DOEPCTL(idx);
> u32 epsiz_reg = dir_in ? DIEPTSIZ(idx) : DOEPTSIZ(idx);
> u32 ints;
> - u32 ctrl;
>
> ints = dwc2_gadget_read_ep_interrupts(hsotg, idx, dir_in);
> - ctrl = dwc2_readl(hsotg, epctl_reg);
As you know, lots of hardware requires reads to happen to do things, so
are you sure it is safe to remove this read call?
thanks,
greg k-h
Hi,
On 7/3/2020 11:29 AM, Greg KH wrote:
> On Thu, Jul 02, 2020 at 03:46:06PM +0100, Lee Jones wrote:
>> Commit ec1f9d9f01384 ("usb: dwc2: gadget: parity fix in isochronous mode") moved
>> these checks to dwc2_hsotg_change_ep_iso_parity() back in 2015. The assigned
>> value hasn't been read back since. Let's remove the unnecessary H/W read.
>>
>> Fixes the following W=1 warning:
>>
>> drivers/usb/dwc2/gadget.c: In function ‘dwc2_hsotg_epint’:
>> drivers/usb/dwc2/gadget.c:2981:6: warning: variable ‘ctrl’ set but not used [-Wunused-but-set-variable]
>> 2981 | u32 ctrl;
>> | ^~~~
>>
>> Cc: Minas Harutyunyan <[email protected]>
>> Cc: Ben Dooks <[email protected]>
>> Signed-off-by: Lee Jones <[email protected]>
>> ---
>> drivers/usb/dwc2/gadget.c | 2 --
>> 1 file changed, 2 deletions(-)
>>
>> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
>> index 116e6175c7a48..fa07e3fcb8841 100644
>> --- a/drivers/usb/dwc2/gadget.c
>> +++ b/drivers/usb/dwc2/gadget.c
>> @@ -2975,10 +2975,8 @@ static void dwc2_hsotg_epint(struct dwc2_hsotg *hsotg, unsigned int idx,
>> u32 epctl_reg = dir_in ? DIEPCTL(idx) : DOEPCTL(idx);
>> u32 epsiz_reg = dir_in ? DIEPTSIZ(idx) : DOEPTSIZ(idx);
>> u32 ints;
>> - u32 ctrl;
>>
>> ints = dwc2_gadget_read_ep_interrupts(hsotg, idx, dir_in);
>> - ctrl = dwc2_readl(hsotg, epctl_reg);
>
> As you know, lots of hardware requires reads to happen to do things, so
> are you sure it is safe to remove this read call?
>
Greg, yes, it's Ok to remove this unnecessary read which remained from
previous implementations.
Lee, please add "Fixes:" tag and resubmit v2.
Thanks,
Minas
> thanks,
>
> greg k-h
>
On Fri, Jul 03, 2020 at 07:38:16AM +0000, Minas Harutyunyan wrote:
> Hi,
>
> On 7/3/2020 11:29 AM, Greg KH wrote:
> > On Thu, Jul 02, 2020 at 03:46:06PM +0100, Lee Jones wrote:
> >> Commit ec1f9d9f01384 ("usb: dwc2: gadget: parity fix in isochronous mode") moved
> >> these checks to dwc2_hsotg_change_ep_iso_parity() back in 2015. The assigned
> >> value hasn't been read back since. Let's remove the unnecessary H/W read.
> >>
> >> Fixes the following W=1 warning:
> >>
> >> drivers/usb/dwc2/gadget.c: In function ‘dwc2_hsotg_epint’:
> >> drivers/usb/dwc2/gadget.c:2981:6: warning: variable ‘ctrl’ set but not used [-Wunused-but-set-variable]
> >> 2981 | u32 ctrl;
> >> | ^~~~
> >>
> >> Cc: Minas Harutyunyan <[email protected]>
> >> Cc: Ben Dooks <[email protected]>
> >> Signed-off-by: Lee Jones <[email protected]>
> >> ---
> >> drivers/usb/dwc2/gadget.c | 2 --
> >> 1 file changed, 2 deletions(-)
> >>
> >> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> >> index 116e6175c7a48..fa07e3fcb8841 100644
> >> --- a/drivers/usb/dwc2/gadget.c
> >> +++ b/drivers/usb/dwc2/gadget.c
> >> @@ -2975,10 +2975,8 @@ static void dwc2_hsotg_epint(struct dwc2_hsotg *hsotg, unsigned int idx,
> >> u32 epctl_reg = dir_in ? DIEPCTL(idx) : DOEPCTL(idx);
> >> u32 epsiz_reg = dir_in ? DIEPTSIZ(idx) : DOEPTSIZ(idx);
> >> u32 ints;
> >> - u32 ctrl;
> >>
> >> ints = dwc2_gadget_read_ep_interrupts(hsotg, idx, dir_in);
> >> - ctrl = dwc2_readl(hsotg, epctl_reg);
> >
> > As you know, lots of hardware requires reads to happen to do things, so
> > are you sure it is safe to remove this read call?
> >
>
> Greg, yes, it's Ok to remove this unnecessary read which remained from
> previous implementations.
Great, thanks for confirming!
greg k-h
Hi,
On 7/3/2020 11:43 AM, Greg KH wrote:
> On Fri, Jul 03, 2020 at 07:38:16AM +0000, Minas Harutyunyan wrote:
>> Hi,
>>
>> On 7/3/2020 11:29 AM, Greg KH wrote:
>>> On Thu, Jul 02, 2020 at 03:46:06PM +0100, Lee Jones wrote:
>>>> Commit ec1f9d9f01384 ("usb: dwc2: gadget: parity fix in isochronous mode") moved
>>>> these checks to dwc2_hsotg_change_ep_iso_parity() back in 2015. The assigned
>>>> value hasn't been read back since. Let's remove the unnecessary H/W read.
>>>>
>>>> Fixes the following W=1 warning:
>>>>
>>>> drivers/usb/dwc2/gadget.c: In function ‘dwc2_hsotg_epint’:
>>>> drivers/usb/dwc2/gadget.c:2981:6: warning: variable ‘ctrl’ set but not used [-Wunused-but-set-variable]
>>>> 2981 | u32 ctrl;
>>>> | ^~~~
>>>>
>>>> Cc: Minas Harutyunyan <[email protected]>
>>>> Cc: Ben Dooks <[email protected]>
>>>> Signed-off-by: Lee Jones <[email protected]>
>>>> ---
>>>> drivers/usb/dwc2/gadget.c | 2 --
>>>> 1 file changed, 2 deletions(-)
>>>>
>>>> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
>>>> index 116e6175c7a48..fa07e3fcb8841 100644
>>>> --- a/drivers/usb/dwc2/gadget.c
>>>> +++ b/drivers/usb/dwc2/gadget.c
>>>> @@ -2975,10 +2975,8 @@ static void dwc2_hsotg_epint(struct dwc2_hsotg *hsotg, unsigned int idx,
>>>> u32 epctl_reg = dir_in ? DIEPCTL(idx) : DOEPCTL(idx);
>>>> u32 epsiz_reg = dir_in ? DIEPTSIZ(idx) : DOEPTSIZ(idx);
>>>> u32 ints;
>>>> - u32 ctrl;
>>>>
>>>> ints = dwc2_gadget_read_ep_interrupts(hsotg, idx, dir_in);
>>>> - ctrl = dwc2_readl(hsotg, epctl_reg);
>>>
>>> As you know, lots of hardware requires reads to happen to do things, so
>>> are you sure it is safe to remove this read call?
>>>
>>
>> Greg, yes, it's Ok to remove this unnecessary read which remained from
>> previous implementations.
>
> Great, thanks for confirming!
>
Acked-by: Minas Harutyunyan <[email protected]>
> greg k-h
>
On Fri, 03 Jul 2020, Minas Harutyunyan wrote:
> Hi,
>
> On 7/3/2020 11:29 AM, Greg KH wrote:
> > On Thu, Jul 02, 2020 at 03:46:06PM +0100, Lee Jones wrote:
> >> Commit ec1f9d9f01384 ("usb: dwc2: gadget: parity fix in isochronous mode") moved
> >> these checks to dwc2_hsotg_change_ep_iso_parity() back in 2015. The assigned
> >> value hasn't been read back since. Let's remove the unnecessary H/W read.
> >>
> >> Fixes the following W=1 warning:
> >>
> >> drivers/usb/dwc2/gadget.c: In function ‘dwc2_hsotg_epint’:
> >> drivers/usb/dwc2/gadget.c:2981:6: warning: variable ‘ctrl’ set but not used [-Wunused-but-set-variable]
> >> 2981 | u32 ctrl;
> >> | ^~~~
> >>
> >> Cc: Minas Harutyunyan <[email protected]>
> >> Cc: Ben Dooks <[email protected]>
> >> Signed-off-by: Lee Jones <[email protected]>
> >> ---
> >> drivers/usb/dwc2/gadget.c | 2 --
> >> 1 file changed, 2 deletions(-)
> >>
> >> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> >> index 116e6175c7a48..fa07e3fcb8841 100644
> >> --- a/drivers/usb/dwc2/gadget.c
> >> +++ b/drivers/usb/dwc2/gadget.c
> >> @@ -2975,10 +2975,8 @@ static void dwc2_hsotg_epint(struct dwc2_hsotg *hsotg, unsigned int idx,
> >> u32 epctl_reg = dir_in ? DIEPCTL(idx) : DOEPCTL(idx);
> >> u32 epsiz_reg = dir_in ? DIEPTSIZ(idx) : DOEPTSIZ(idx);
> >> u32 ints;
> >> - u32 ctrl;
> >>
> >> ints = dwc2_gadget_read_ep_interrupts(hsotg, idx, dir_in);
> >> - ctrl = dwc2_readl(hsotg, epctl_reg);
> >
> > As you know, lots of hardware requires reads to happen to do things, so
> > are you sure it is safe to remove this read call?
> >
>
> Greg, yes, it's Ok to remove this unnecessary read which remained from
> previous implementations.
>
> Lee, please add "Fixes:" tag and resubmit v2.
Is this suitable for Stable Greg?
--
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
On Fri, Jul 03, 2020 at 06:16:26PM +0100, Lee Jones wrote:
> On Fri, 03 Jul 2020, Minas Harutyunyan wrote:
>
> > Hi,
> >
> > On 7/3/2020 11:29 AM, Greg KH wrote:
> > > On Thu, Jul 02, 2020 at 03:46:06PM +0100, Lee Jones wrote:
> > >> Commit ec1f9d9f01384 ("usb: dwc2: gadget: parity fix in isochronous mode") moved
> > >> these checks to dwc2_hsotg_change_ep_iso_parity() back in 2015. The assigned
> > >> value hasn't been read back since. Let's remove the unnecessary H/W read.
> > >>
> > >> Fixes the following W=1 warning:
> > >>
> > >> drivers/usb/dwc2/gadget.c: In function ‘dwc2_hsotg_epint’:
> > >> drivers/usb/dwc2/gadget.c:2981:6: warning: variable ‘ctrl’ set but not used [-Wunused-but-set-variable]
> > >> 2981 | u32 ctrl;
> > >> | ^~~~
> > >>
> > >> Cc: Minas Harutyunyan <[email protected]>
> > >> Cc: Ben Dooks <[email protected]>
> > >> Signed-off-by: Lee Jones <[email protected]>
> > >> ---
> > >> drivers/usb/dwc2/gadget.c | 2 --
> > >> 1 file changed, 2 deletions(-)
> > >>
> > >> diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
> > >> index 116e6175c7a48..fa07e3fcb8841 100644
> > >> --- a/drivers/usb/dwc2/gadget.c
> > >> +++ b/drivers/usb/dwc2/gadget.c
> > >> @@ -2975,10 +2975,8 @@ static void dwc2_hsotg_epint(struct dwc2_hsotg *hsotg, unsigned int idx,
> > >> u32 epctl_reg = dir_in ? DIEPCTL(idx) : DOEPCTL(idx);
> > >> u32 epsiz_reg = dir_in ? DIEPTSIZ(idx) : DOEPTSIZ(idx);
> > >> u32 ints;
> > >> - u32 ctrl;
> > >>
> > >> ints = dwc2_gadget_read_ep_interrupts(hsotg, idx, dir_in);
> > >> - ctrl = dwc2_readl(hsotg, epctl_reg);
> > >
> > > As you know, lots of hardware requires reads to happen to do things, so
> > > are you sure it is safe to remove this read call?
> > >
> >
> > Greg, yes, it's Ok to remove this unnecessary read which remained from
> > previous implementations.
> >
> > Lee, please add "Fixes:" tag and resubmit v2.
>
> Is this suitable for Stable Greg?
Does it fix something that people have ever noticed or care about?
Given the age of the bug, I doubt it :)
thanks,
greg k-h