diff mbox series

[21/24] usb: host: xhci: Move array of structs from the stack onto the heap

Message ID 20210526130037.856068-22-lee.jones@linaro.org
State New
Headers show
Series Rid W=1 warnings from USB | expand

Commit Message

Lee Jones May 26, 2021, 1 p.m. UTC 
Fixes the following W=1 kernel build warning(s):

 drivers/usb/host/xhci.c: In function ‘xhci_reserve_bandwidth’:
 drivers/usb/host/xhci.c:2859:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=]

Cc: Mathias Nyman <mathias.nyman@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>

---
 drivers/usb/host/xhci.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

-- 
2.31.1

Comments

Sergei Shtylyov May 26, 2021, 2:21 p.m. UTC | #1 
On 5/26/21 4:00 PM, Lee Jones wrote:

> Fixes the following W=1 kernel build warning(s):

> 

>  drivers/usb/host/xhci.c: In function ‘xhci_reserve_bandwidth’:

>  drivers/usb/host/xhci.c:2859:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=]

> 

> Cc: Mathias Nyman <mathias.nyman@intel.com>

> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

> Cc: linux-usb@vger.kernel.org

> Signed-off-by: Lee Jones <lee.jones@linaro.org>

> ---

>  drivers/usb/host/xhci.c | 8 +++++++-

>  1 file changed, 7 insertions(+), 1 deletion(-)

> 

> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

> index ac2a7d4288883..40ce4b4eb12ad 100644

> --- a/drivers/usb/host/xhci.c

> +++ b/drivers/usb/host/xhci.c

[...]
> @@ -2788,6 +2788,10 @@ static int xhci_reserve_bandwidth(struct xhci_hcd *xhci,

>  		return -ENOMEM;

>  	}

>  

> +	ep_bw_info = kzalloc(sizeof(*ep_bw_info) * 31, GFP_KERNEL);


   Why not kcalloc()?

[...]

MBR, Sergei
Lee Jones May 26, 2021, 2:44 p.m. UTC | #2 
On Wed, 26 May 2021, Sergei Shtylyov wrote:

> On 5/26/21 4:00 PM, Lee Jones wrote:

> 

> > Fixes the following W=1 kernel build warning(s):

> > 

> >  drivers/usb/host/xhci.c: In function ‘xhci_reserve_bandwidth’:

> >  drivers/usb/host/xhci.c:2859:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=]

> > 

> > Cc: Mathias Nyman <mathias.nyman@intel.com>

> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

> > Cc: linux-usb@vger.kernel.org

> > Signed-off-by: Lee Jones <lee.jones@linaro.org>

> > ---

> >  drivers/usb/host/xhci.c | 8 +++++++-

> >  1 file changed, 7 insertions(+), 1 deletion(-)

> > 

> > diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

> > index ac2a7d4288883..40ce4b4eb12ad 100644

> > --- a/drivers/usb/host/xhci.c

> > +++ b/drivers/usb/host/xhci.c

> [...]

> > @@ -2788,6 +2788,10 @@ static int xhci_reserve_bandwidth(struct xhci_hcd *xhci,

> >  		return -ENOMEM;

> >  	}

> >  

> > +	ep_bw_info = kzalloc(sizeof(*ep_bw_info) * 31, GFP_KERNEL);

> 

>    Why not kcalloc()?


No particular reason.  Muscle memory I guess.

Happy either way.

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
Sergei Shtylyov May 26, 2021, 2:59 p.m. UTC | #3 
On 5/26/21 5:44 PM, Lee Jones wrote:

[...]
>>> Fixes the following W=1 kernel build warning(s):

>>>

>>>  drivers/usb/host/xhci.c: In function ‘xhci_reserve_bandwidth’:

>>>  drivers/usb/host/xhci.c:2859:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=]

>>>

>>> Cc: Mathias Nyman <mathias.nyman@intel.com>

>>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

>>> Cc: linux-usb@vger.kernel.org

>>> Signed-off-by: Lee Jones <lee.jones@linaro.org>

>>> ---

>>>  drivers/usb/host/xhci.c | 8 +++++++-

>>>  1 file changed, 7 insertions(+), 1 deletion(-)

>>>

>>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

>>> index ac2a7d4288883..40ce4b4eb12ad 100644

>>> --- a/drivers/usb/host/xhci.c

>>> +++ b/drivers/usb/host/xhci.c

>> [...]

>>> @@ -2788,6 +2788,10 @@ static int xhci_reserve_bandwidth(struct xhci_hcd *xhci,

>>>  		return -ENOMEM;

>>>  	}

>>>  

>>> +	ep_bw_info = kzalloc(sizeof(*ep_bw_info) * 31, GFP_KERNEL);

>>

>>    Why not kcalloc()?

> 

> No particular reason.  Muscle memory I guess.

> 

> Happy either way.


    kcalloc( is designed for allocatiung arrays and clearing them, like calloc(),
so let's stick wuth it...

MBR, Sergei
Lee Jones May 26, 2021, 3:28 p.m. UTC | #4 
On Wed, 26 May 2021, Sergei Shtylyov wrote:

> On 5/26/21 5:44 PM, Lee Jones wrote:

> 

> [...]

> >>> Fixes the following W=1 kernel build warning(s):

> >>>

> >>>  drivers/usb/host/xhci.c: In function ‘xhci_reserve_bandwidth’:

> >>>  drivers/usb/host/xhci.c:2859:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=]

> >>>

> >>> Cc: Mathias Nyman <mathias.nyman@intel.com>

> >>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

> >>> Cc: linux-usb@vger.kernel.org

> >>> Signed-off-by: Lee Jones <lee.jones@linaro.org>

> >>> ---

> >>>  drivers/usb/host/xhci.c | 8 +++++++-

> >>>  1 file changed, 7 insertions(+), 1 deletion(-)

> >>>

> >>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

> >>> index ac2a7d4288883..40ce4b4eb12ad 100644

> >>> --- a/drivers/usb/host/xhci.c

> >>> +++ b/drivers/usb/host/xhci.c

> >> [...]

> >>> @@ -2788,6 +2788,10 @@ static int xhci_reserve_bandwidth(struct xhci_hcd *xhci,

> >>>  		return -ENOMEM;

> >>>  	}

> >>>  

> >>> +	ep_bw_info = kzalloc(sizeof(*ep_bw_info) * 31, GFP_KERNEL);

> >>

> >>    Why not kcalloc()?

> > 

> > No particular reason.  Muscle memory I guess.

> > 

> > Happy either way.

> 

>     kcalloc( is designed for allocatiung arrays and clearing them, like calloc(),

> so let's stick wuth it...


No problem.  Will fix.

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
Mathias Nyman May 27, 2021, 11:36 a.m. UTC | #5 
On 26.5.2021 18.28, Lee Jones wrote:
> On Wed, 26 May 2021, Sergei Shtylyov wrote:

> 

>> On 5/26/21 5:44 PM, Lee Jones wrote:

>>

>> [...]

>>>>> Fixes the following W=1 kernel build warning(s):

>>>>>

>>>>>  drivers/usb/host/xhci.c: In function ‘xhci_reserve_bandwidth’:

>>>>>  drivers/usb/host/xhci.c:2859:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=]

>>>>>

>>>>> Cc: Mathias Nyman <mathias.nyman@intel.com>

>>>>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

>>>>> Cc: linux-usb@vger.kernel.org

>>>>> Signed-off-by: Lee Jones <lee.jones@linaro.org>

>>>>> ---

>>>>>  drivers/usb/host/xhci.c | 8 +++++++-

>>>>>  1 file changed, 7 insertions(+), 1 deletion(-)

>>>>>

>>>>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

>>>>> index ac2a7d4288883..40ce4b4eb12ad 100644

>>>>> --- a/drivers/usb/host/xhci.c

>>>>> +++ b/drivers/usb/host/xhci.c

>>>> [...]

>>>>> @@ -2788,6 +2788,10 @@ static int xhci_reserve_bandwidth(struct xhci_hcd *xhci,

>>>>>  		return -ENOMEM;

>>>>>  	}

>>>>>  

>>>>> +	ep_bw_info = kzalloc(sizeof(*ep_bw_info) * 31, GFP_KERNEL);


GFP_KERNEL might not be suitable for all cases.

xhci_reserve_bandwidth() is called from xhci_configure_endpoint(), which again
is called from a lot of places.
For example from xhci_update_hub_device() which can be called with GFP_NOIO mem_flags.

-Mathias
Lee Jones June 1, 2021, 9:25 a.m. UTC | #6 
On Thu, 27 May 2021, Mathias Nyman wrote:

> On 26.5.2021 18.28, Lee Jones wrote:

> > On Wed, 26 May 2021, Sergei Shtylyov wrote:

> > 

> >> On 5/26/21 5:44 PM, Lee Jones wrote:

> >>

> >> [...]

> >>>>> Fixes the following W=1 kernel build warning(s):

> >>>>>

> >>>>>  drivers/usb/host/xhci.c: In function ‘xhci_reserve_bandwidth’:

> >>>>>  drivers/usb/host/xhci.c:2859:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=]

> >>>>>

> >>>>> Cc: Mathias Nyman <mathias.nyman@intel.com>

> >>>>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

> >>>>> Cc: linux-usb@vger.kernel.org

> >>>>> Signed-off-by: Lee Jones <lee.jones@linaro.org>

> >>>>> ---

> >>>>>  drivers/usb/host/xhci.c | 8 +++++++-

> >>>>>  1 file changed, 7 insertions(+), 1 deletion(-)

> >>>>>

> >>>>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

> >>>>> index ac2a7d4288883..40ce4b4eb12ad 100644

> >>>>> --- a/drivers/usb/host/xhci.c

> >>>>> +++ b/drivers/usb/host/xhci.c

> >>>> [...]

> >>>>> @@ -2788,6 +2788,10 @@ static int xhci_reserve_bandwidth(struct xhci_hcd *xhci,

> >>>>>  		return -ENOMEM;

> >>>>>  	}

> >>>>>  

> >>>>> +	ep_bw_info = kzalloc(sizeof(*ep_bw_info) * 31, GFP_KERNEL);

> 

> GFP_KERNEL might not be suitable for all cases.

> 

> xhci_reserve_bandwidth() is called from xhci_configure_endpoint(), which again

> is called from a lot of places.

> For example from xhci_update_hub_device() which can be called with GFP_NOIO mem_flags.


What do you suggest as an alternative?

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
Lee Jones June 22, 2021, 10:47 a.m. UTC | #7 
On Tue, 01 Jun 2021, Lee Jones wrote:

> On Thu, 27 May 2021, Mathias Nyman wrote:

> 

> > On 26.5.2021 18.28, Lee Jones wrote:

> > > On Wed, 26 May 2021, Sergei Shtylyov wrote:

> > > 

> > >> On 5/26/21 5:44 PM, Lee Jones wrote:

> > >>

> > >> [...]

> > >>>>> Fixes the following W=1 kernel build warning(s):

> > >>>>>

> > >>>>>  drivers/usb/host/xhci.c: In function ‘xhci_reserve_bandwidth’:

> > >>>>>  drivers/usb/host/xhci.c:2859:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=]

> > >>>>>

> > >>>>> Cc: Mathias Nyman <mathias.nyman@intel.com>

> > >>>>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

> > >>>>> Cc: linux-usb@vger.kernel.org

> > >>>>> Signed-off-by: Lee Jones <lee.jones@linaro.org>

> > >>>>> ---

> > >>>>>  drivers/usb/host/xhci.c | 8 +++++++-

> > >>>>>  1 file changed, 7 insertions(+), 1 deletion(-)

> > >>>>>

> > >>>>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

> > >>>>> index ac2a7d4288883..40ce4b4eb12ad 100644

> > >>>>> --- a/drivers/usb/host/xhci.c

> > >>>>> +++ b/drivers/usb/host/xhci.c

> > >>>> [...]

> > >>>>> @@ -2788,6 +2788,10 @@ static int xhci_reserve_bandwidth(struct xhci_hcd *xhci,

> > >>>>>  		return -ENOMEM;

> > >>>>>  	}

> > >>>>>  

> > >>>>> +	ep_bw_info = kzalloc(sizeof(*ep_bw_info) * 31, GFP_KERNEL);

> > 

> > GFP_KERNEL might not be suitable for all cases.

> > 

> > xhci_reserve_bandwidth() is called from xhci_configure_endpoint(), which again

> > is called from a lot of places.

> > For example from xhci_update_hub_device() which can be called with GFP_NOIO mem_flags.

> 

> What do you suggest as an alternative?


Just working on rectifying this now.

Which Get Free Page flag do you suggest here please?

-- 
Lee Jones [李琼斯]
Senior Technical Lead - Developer Services
Linaro.org │ Open source software for Arm SoCs
Follow Linaro: Facebook | Twitter | Blog
Mathias Nyman June 22, 2021, 11:32 a.m. UTC | #8 
On 22.6.2021 13.47, Lee Jones wrote:
> On Tue, 01 Jun 2021, Lee Jones wrote:

> 

>> On Thu, 27 May 2021, Mathias Nyman wrote:

>>

>>> On 26.5.2021 18.28, Lee Jones wrote:

>>>> On Wed, 26 May 2021, Sergei Shtylyov wrote:

>>>>

>>>>> On 5/26/21 5:44 PM, Lee Jones wrote:

>>>>>

>>>>> [...]

>>>>>>>> Fixes the following W=1 kernel build warning(s):

>>>>>>>>

>>>>>>>>  drivers/usb/host/xhci.c: In function ‘xhci_reserve_bandwidth’:

>>>>>>>>  drivers/usb/host/xhci.c:2859:1: warning: the frame size of 1032 bytes is larger than 1024 bytes [-Wframe-larger-than=]

>>>>>>>>

>>>>>>>> Cc: Mathias Nyman <mathias.nyman@intel.com>

>>>>>>>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

>>>>>>>> Cc: linux-usb@vger.kernel.org

>>>>>>>> Signed-off-by: Lee Jones <lee.jones@linaro.org>

>>>>>>>> ---

>>>>>>>>  drivers/usb/host/xhci.c | 8 +++++++-

>>>>>>>>  1 file changed, 7 insertions(+), 1 deletion(-)

>>>>>>>>

>>>>>>>> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c

>>>>>>>> index ac2a7d4288883..40ce4b4eb12ad 100644

>>>>>>>> --- a/drivers/usb/host/xhci.c

>>>>>>>> +++ b/drivers/usb/host/xhci.c

>>>>>>> [...]

>>>>>>>> @@ -2788,6 +2788,10 @@ static int xhci_reserve_bandwidth(struct xhci_hcd *xhci,

>>>>>>>>  		return -ENOMEM;

>>>>>>>>  	}

>>>>>>>>  

>>>>>>>> +	ep_bw_info = kzalloc(sizeof(*ep_bw_info) * 31, GFP_KERNEL);

>>>

>>> GFP_KERNEL might not be suitable for all cases.

>>>

>>> xhci_reserve_bandwidth() is called from xhci_configure_endpoint(), which again

>>> is called from a lot of places.

>>> For example from xhci_update_hub_device() which can be called with GFP_NOIO mem_flags.

>>

>> What do you suggest as an alternative?

> 

> Just working on rectifying this now.

> 

> Which Get Free Page flag do you suggest here please?

> 


xhci_reserve_bandwidth() is called with spin lock held, so probably GFP_ATOMIC

But that whole function would need more attention.
It's always consuming  31 * sizeof(*ep_bw_info) bytes to store fallback values.
Normal use case is that just one, or a couple endpoints are changing, and we know which ones do.

-Mathias


just one enpoint changing.
diff mbox series

Patch

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index ac2a7d4288883..40ce4b4eb12ad 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -2773,7 +2773,7 @@  static int xhci_reserve_bandwidth(struct xhci_hcd *xhci,
 		struct xhci_virt_device *virt_dev,
 		struct xhci_container_ctx *in_ctx)
 {
-	struct xhci_bw_info ep_bw_info[31];
+	struct xhci_bw_info *ep_bw_info;
 	int i;
 	struct xhci_input_control_ctx *ctrl_ctx;
 	int old_active_eps = 0;
@@ -2788,6 +2788,10 @@  static int xhci_reserve_bandwidth(struct xhci_hcd *xhci,
 		return -ENOMEM;
 	}
 
+	ep_bw_info = kzalloc(sizeof(*ep_bw_info) * 31, GFP_KERNEL);
+	if (!ep_bw_info)
+		return -ENOMEM;
+
 	for (i = 0; i < 31; i++) {
 		if (!EP_IS_ADDED(ctrl_ctx, i) && !EP_IS_DROPPED(ctrl_ctx, i))
 			continue;
@@ -2824,6 +2828,7 @@  static int xhci_reserve_bandwidth(struct xhci_hcd *xhci,
 		 * Update the number of active TTs.
 		 */
 		xhci_update_tt_active_eps(xhci, virt_dev, old_active_eps);
+		kfree(ep_bw_info);
 		return 0;
 	}
 
@@ -2855,6 +2860,7 @@  static int xhci_reserve_bandwidth(struct xhci_hcd *xhci,
 					&virt_dev->eps[i],
 					virt_dev->tt_info);
 	}
+	kfree(ep_bw_info);
 	return -ENOMEM;
 }