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* [U-Boot] [PATCH v2] usb: f_mass_storage: Fix compile on x86
@ 2018-04-26 20:47 Bryan O'Donoghue
  2018-04-26 21:21 ` Marek Vasut
  0 siblings, 1 reply; 4+ messages in thread
From: Bryan O'Donoghue @ 2018-04-26 20:47 UTC (permalink / raw)
  To: u-boot

Compiling the f_mass_storage driver for an x86 target results in a
compilation error as set_bit and clear_bit are provided by bitops.h

The local version of set_bit and clear_bit are doing some IP-block specific
bit-twiddling so we don't actually want to accidentally pick up the
bitops.h version of set_bit and clear bit.

This patch renames to _set_bit() and _clear_bit() respectively to avoid the
namespace collision.

Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Lukasz Majewski <lukma@denx.de>
Cc: Marek Vasut <marex@denx.de>
---
 drivers/usb/gadget/f_mass_storage.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
index 1ecb92ac6b..524c43419f 100644
--- a/drivers/usb/gadget/f_mass_storage.c
+++ b/drivers/usb/gadget/f_mass_storage.c
@@ -283,7 +283,7 @@ static const char fsg_string_interface[] = "Mass Storage";
 struct kref {int x; };
 struct completion {int x; };
 
-inline void set_bit(int nr, volatile void *addr)
+inline void _set_bit(int nr, volatile void *addr)
 {
 	int	mask;
 	unsigned int *a = (unsigned int *) addr;
@@ -293,7 +293,7 @@ inline void set_bit(int nr, volatile void *addr)
 	*a |= mask;
 }
 
-inline void clear_bit(int nr, volatile void *addr)
+inline void _clear_bit(int nr, volatile void *addr)
 {
 	int	mask;
 	unsigned int *a = (unsigned int *) addr;
@@ -2086,7 +2086,7 @@ static int received_cbw(struct fsg_dev *fsg, struct fsg_buffhd *bh)
 		 * we can simply accept and discard any data received
 		 * until the next reset. */
 		wedge_bulk_in_endpoint(fsg);
-		set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
+		_set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
 		return -EINVAL;
 	}
 
@@ -2250,7 +2250,7 @@ reset:
 	fsg->bulk_out_enabled = 1;
 	common->bulk_out_maxpacket =
 				le16_to_cpu(get_unaligned(&d->wMaxPacketSize));
-	clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
+	_clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
 
 	/* Allocate the requests */
 	for (i = 0; i < FSG_NUM_BUFFERS; ++i) {
-- 
2.17.0

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [U-Boot] [PATCH v2] usb: f_mass_storage: Fix compile on x86
  2018-04-26 20:47 [U-Boot] [PATCH v2] usb: f_mass_storage: Fix compile on x86 Bryan O'Donoghue
@ 2018-04-26 21:21 ` Marek Vasut
  2018-04-26 21:53   ` Bryan O'Donoghue
  0 siblings, 1 reply; 4+ messages in thread
From: Marek Vasut @ 2018-04-26 21:21 UTC (permalink / raw)
  To: u-boot

On 04/26/2018 10:47 PM, Bryan O'Donoghue wrote:
> Compiling the f_mass_storage driver for an x86 target results in a
> compilation error as set_bit and clear_bit are provided by bitops.h
> 
> The local version of set_bit and clear_bit are doing some IP-block specific
> bit-twiddling so we don't actually want to accidentally pick up the
> bitops.h version of set_bit and clear bit.
> 
> This patch renames to _set_bit() and _clear_bit() respectively to avoid the
> namespace collision.
> 
> Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
> Cc: Lukasz Majewski <lukma@denx.de>
> Cc: Marek Vasut <marex@denx.de>
> ---
>  drivers/usb/gadget/f_mass_storage.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
> index 1ecb92ac6b..524c43419f 100644
> --- a/drivers/usb/gadget/f_mass_storage.c
> +++ b/drivers/usb/gadget/f_mass_storage.c
> @@ -283,7 +283,7 @@ static const char fsg_string_interface[] = "Mass Storage";
>  struct kref {int x; };
>  struct completion {int x; };
>  
> -inline void set_bit(int nr, volatile void *addr)
> +inline void _set_bit(int nr, volatile void *addr)

Do not name functions with _ prefix. Also, I think the suggestion from
Lukasz was better.

-- 
Best regards,
Marek Vasut

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [U-Boot] [PATCH v2] usb: f_mass_storage: Fix compile on x86
  2018-04-26 21:21 ` Marek Vasut
@ 2018-04-26 21:53   ` Bryan O'Donoghue
  2018-04-27  7:36     ` Lukasz Majewski
  0 siblings, 1 reply; 4+ messages in thread
From: Bryan O'Donoghue @ 2018-04-26 21:53 UTC (permalink / raw)
  To: u-boot

On 26/04/18 22:21, Marek Vasut wrote:
> On 04/26/2018 10:47 PM, Bryan O'Donoghue wrote:
>> Compiling the f_mass_storage driver for an x86 target results in a
>> compilation error as set_bit and clear_bit are provided by bitops.h
>>
>> The local version of set_bit and clear_bit are doing some IP-block specific
>> bit-twiddling so we don't actually want to accidentally pick up the
>> bitops.h version of set_bit and clear bit.
>>
>> This patch renames to _set_bit() and _clear_bit() respectively to avoid the
>> namespace collision.
>>
>> Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
>> Cc: Lukasz Majewski <lukma@denx.de>
>> Cc: Marek Vasut <marex@denx.de>
>> ---
>>   drivers/usb/gadget/f_mass_storage.c | 8 ++++----
>>   1 file changed, 4 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/usb/gadget/f_mass_storage.c b/drivers/usb/gadget/f_mass_storage.c
>> index 1ecb92ac6b..524c43419f 100644
>> --- a/drivers/usb/gadget/f_mass_storage.c
>> +++ b/drivers/usb/gadget/f_mass_storage.c
>> @@ -283,7 +283,7 @@ static const char fsg_string_interface[] = "Mass Storage";
>>   struct kref {int x; };
>>   struct completion {int x; };
>>   
>> -inline void set_bit(int nr, volatile void *addr)
>> +inline void _set_bit(int nr, volatile void *addr)
> 
> Do not name functions with _ prefix. Also, I think the suggestion from
> Lukasz was better.
> 

Funny - I had assumed we were seting the bit like this for a good reason 
but...

This code seems to be something that just crept in along the way

inline void set_bit(int nr, volatile void *addr)
{
         int     mask;
         unsigned int *a = (unsigned int *) addr;

         a += nr >> 5;
         mask = 1 << (nr & 0x1f);
         *a |= mask;
}

but on Linux the upstream driver actually does arch-specific 
set_bit/clear_bit

Looking at it a bit more.. I'm not quite sure how/why we are setting the 
bit like that

git blame drivers/usb/gadget/f_mass_storage.c

b4d36f6809f (Piotr Wilczek          2013-03-05 12:10:16 +0100  286) 
inline void set_bit(int nr, volatile void *addr)

The f_mass_storage.c source file from v2.6.36 Linux kernel.

     commit 8876f5e7d3b2a320777dd4f6f5301d474c97a06c
     Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
     Date:   Mon Jun 21 13:57:09 2010 +0200


linux$ git checkout 8876f5e7d3b2a320777dd4f6f5301d474c97a06c -- 
drivers/usb/gadget/f_mass_storage.c

Doesn't have a local copy of set_bit/clear_bit at all, which is 
confusing - I guess bitops.h in 2013 didn't have set_bit/clear_bit..

But yeah - I guess we really should be using arch-specific 
get_bit/set_bit after all...

---
bod

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [U-Boot] [PATCH v2] usb: f_mass_storage: Fix compile on x86
  2018-04-26 21:53   ` Bryan O'Donoghue
@ 2018-04-27  7:36     ` Lukasz Majewski
  0 siblings, 0 replies; 4+ messages in thread
From: Lukasz Majewski @ 2018-04-27  7:36 UTC (permalink / raw)
  To: u-boot

Hi Bryan,

> On 26/04/18 22:21, Marek Vasut wrote:
> > On 04/26/2018 10:47 PM, Bryan O'Donoghue wrote:  
> >> Compiling the f_mass_storage driver for an x86 target results in a
> >> compilation error as set_bit and clear_bit are provided by bitops.h
> >>
> >> The local version of set_bit and clear_bit are doing some IP-block
> >> specific bit-twiddling so we don't actually want to accidentally
> >> pick up the bitops.h version of set_bit and clear bit.
> >>
> >> This patch renames to _set_bit() and _clear_bit() respectively to
> >> avoid the namespace collision.
> >>
> >> Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
> >> Cc: Lukasz Majewski <lukma@denx.de>
> >> Cc: Marek Vasut <marex@denx.de>
> >> ---
> >>   drivers/usb/gadget/f_mass_storage.c | 8 ++++----
> >>   1 file changed, 4 insertions(+), 4 deletions(-)
> >>
> >> diff --git a/drivers/usb/gadget/f_mass_storage.c
> >> b/drivers/usb/gadget/f_mass_storage.c index 1ecb92ac6b..524c43419f
> >> 100644 --- a/drivers/usb/gadget/f_mass_storage.c
> >> +++ b/drivers/usb/gadget/f_mass_storage.c
> >> @@ -283,7 +283,7 @@ static const char fsg_string_interface[] =
> >> "Mass Storage"; struct kref {int x; };
> >>   struct completion {int x; };
> >>   
> >> -inline void set_bit(int nr, volatile void *addr)
> >> +inline void _set_bit(int nr, volatile void *addr)  
> > 
> > Do not name functions with _ prefix. Also, I think the suggestion
> > from Lukasz was better.
> >   
> 
> Funny - I had assumed we were seting the bit like this for a good
> reason but...
> 
> This code seems to be something that just crept in along the way
> 
> inline void set_bit(int nr, volatile void *addr)
> {
>          int     mask;
>          unsigned int *a = (unsigned int *) addr;
> 
>          a += nr >> 5;
>          mask = 1 << (nr & 0x1f);
>          *a |= mask;
> }
> 
> but on Linux the upstream driver actually does arch-specific 
> set_bit/clear_bit
> 
> Looking at it a bit more.. I'm not quite sure how/why we are setting
> the bit like that
> 
> git blame drivers/usb/gadget/f_mass_storage.c
> 
> b4d36f6809f (Piotr Wilczek          2013-03-05 12:10:16 +0100  286) 
> inline void set_bit(int nr, volatile void *addr)
> 
> The f_mass_storage.c source file from v2.6.36 Linux kernel.
> 
>      commit 8876f5e7d3b2a320777dd4f6f5301d474c97a06c
>      Author: Michal Nazarewicz <m.nazarewicz@samsung.com>
>      Date:   Mon Jun 21 13:57:09 2010 +0200
> 
> 
> linux$ git checkout 8876f5e7d3b2a320777dd4f6f5301d474c97a06c -- 
> drivers/usb/gadget/f_mass_storage.c
> 
> Doesn't have a local copy of set_bit/clear_bit at all, which is 
> confusing - I guess bitops.h in 2013 didn't have set_bit/clear_bit..
> 
> But yeah - I guess we really should be using arch-specific 
> get_bit/set_bit after all...

+1

> 
> ---
> bod
> 




Best regards,

Lukasz Majewski

--

DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
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^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2018-04-27  7:36 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-04-26 20:47 [U-Boot] [PATCH v2] usb: f_mass_storage: Fix compile on x86 Bryan O'Donoghue
2018-04-26 21:21 ` Marek Vasut
2018-04-26 21:53   ` Bryan O'Donoghue
2018-04-27  7:36     ` Lukasz Majewski

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