diff mbox series

[V7,1/6] clk: imx6sl: Use BIT(x) to avoid shifting signed 32-bit value by 31 bits

Message ID 1596034117-24246-2-git-send-email-Anson.Huang@nxp.com (mailing list archive)
State Superseded, archived
Headers show
Series Support building i.MX ARMv8 platforms clock driver as module | expand

Commit Message

Anson Huang July 29, 2020, 2:48 p.m. UTC
Use readl_relaxed() instead of __raw_readl(), and use BIT(x)
instead of (1 << X) to fix below build warning reported by kernel
test robot:

drivers/clk/imx/clk-imx6sl.c:149:49: warning: Shifting signed 32-bit
value by 31 bits is undefined behaviour [shiftTooManyBitsSigned]
     while (!(__raw_readl(anatop_base + PLL_ARM) & BM_PLL_ARM_LOCK))

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reported-by: kernel test robot <lkp@intel.com>
---
Changes since V6:
	- improve the subject.
---
 drivers/clk/imx/clk-imx6sl.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

Comments

Randy Dunlap July 29, 2020, 3:49 p.m. UTC | #1
On 7/29/20 7:48 AM, Anson Huang wrote:
> Use readl_relaxed() instead of __raw_readl(), and use BIT(x)
> instead of (1 << X) to fix below build warning reported by kernel
> test robot:
> 
> drivers/clk/imx/clk-imx6sl.c:149:49: warning: Shifting signed 32-bit
> value by 31 bits is undefined behaviour [shiftTooManyBitsSigned]
>      while (!(__raw_readl(anatop_base + PLL_ARM) & BM_PLL_ARM_LOCK))
> 
> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> Reported-by: kernel test robot <lkp@intel.com>
> ---
> Changes since V6:
> 	- improve the subject.
> ---
>  drivers/clk/imx/clk-imx6sl.c | 15 ++++++++-------
>  1 file changed, 8 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/clk/imx/clk-imx6sl.c b/drivers/clk/imx/clk-imx6sl.c
> index 0f647d1..e69dba1 100644
> --- a/drivers/clk/imx/clk-imx6sl.c
> +++ b/drivers/clk/imx/clk-imx6sl.c
> @@ -3,6 +3,7 @@
>   * Copyright 2013-2014 Freescale Semiconductor, Inc.
>   */
>  
> +#include <linux/bitfield.h>

Hi,
I think you want
#include <linux/bits.h>

for BIT() usage.

>  #include <linux/clk.h>
>  #include <linux/clkdev.h>
>  #include <linux/err.h>
> @@ -14,19 +15,19 @@
>  #include "clk.h"
>  
>  #define CCSR			0xc
> -#define BM_CCSR_PLL1_SW_CLK_SEL	(1 << 2)
> +#define BM_CCSR_PLL1_SW_CLK_SEL	BIT(2)
>  #define CACRR			0x10
>  #define CDHIPR			0x48
> -#define BM_CDHIPR_ARM_PODF_BUSY	(1 << 16)
> +#define BM_CDHIPR_ARM_PODF_BUSY	BIT(16)
>  #define ARM_WAIT_DIV_396M	2
>  #define ARM_WAIT_DIV_792M	4
>  #define ARM_WAIT_DIV_996M	6
>  
>  #define PLL_ARM			0x0
> -#define BM_PLL_ARM_DIV_SELECT	(0x7f << 0)
> -#define BM_PLL_ARM_POWERDOWN	(1 << 12)
> -#define BM_PLL_ARM_ENABLE	(1 << 13)
> -#define BM_PLL_ARM_LOCK		(1 << 31)
> +#define BM_PLL_ARM_DIV_SELECT	0x7f
> +#define BM_PLL_ARM_POWERDOWN	BIT(12)
> +#define BM_PLL_ARM_ENABLE	BIT(13)
> +#define BM_PLL_ARM_LOCK		BIT(31)
>  #define PLL_ARM_DIV_792M	66
>  
>  static const char *step_sels[]		= { "osc", "pll2_pfd2", };


thanks.
Anson Huang July 29, 2020, 11:51 p.m. UTC | #2
Hi, Randy


> Subject: Re: [PATCH V7 1/6] clk: imx6sl: Use BIT(x) to avoid shifting signed
> 32-bit value by 31 bits
> 
> On 7/29/20 7:48 AM, Anson Huang wrote:
> > Use readl_relaxed() instead of __raw_readl(), and use BIT(x) instead
> > of (1 << X) to fix below build warning reported by kernel test robot:
> >
> > drivers/clk/imx/clk-imx6sl.c:149:49: warning: Shifting signed 32-bit
> > value by 31 bits is undefined behaviour [shiftTooManyBitsSigned]
> >      while (!(__raw_readl(anatop_base + PLL_ARM) &
> BM_PLL_ARM_LOCK))
> >
> > Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> > Reported-by: kernel test robot <lkp@intel.com>
> > ---
> > Changes since V6:
> > 	- improve the subject.
> > ---
> >  drivers/clk/imx/clk-imx6sl.c | 15 ++++++++-------
> >  1 file changed, 8 insertions(+), 7 deletions(-)
> >
> > diff --git a/drivers/clk/imx/clk-imx6sl.c
> > b/drivers/clk/imx/clk-imx6sl.c index 0f647d1..e69dba1 100644
> > --- a/drivers/clk/imx/clk-imx6sl.c
> > +++ b/drivers/clk/imx/clk-imx6sl.c
> > @@ -3,6 +3,7 @@
> >   * Copyright 2013-2014 Freescale Semiconductor, Inc.
> >   */
> >
> > +#include <linux/bitfield.h>
> 
> Hi,
> I think you want
> #include <linux/bits.h>
> 
> for BIT() usage.

Actually, the linux/of.h already includes linux/bitops.h and linux/bitops.h includes
linux/bits.h, so I will just drop linux/bitfield.h and send a V8.

Thanks,
Anson
Randy Dunlap July 30, 2020, 12:30 a.m. UTC | #3
On 7/29/20 4:51 PM, Anson Huang wrote:
> Hi, Randy
> 
> 
>> Subject: Re: [PATCH V7 1/6] clk: imx6sl: Use BIT(x) to avoid shifting signed
>> 32-bit value by 31 bits
>>
>> On 7/29/20 7:48 AM, Anson Huang wrote:
>>> Use readl_relaxed() instead of __raw_readl(), and use BIT(x) instead
>>> of (1 << X) to fix below build warning reported by kernel test robot:
>>>
>>> drivers/clk/imx/clk-imx6sl.c:149:49: warning: Shifting signed 32-bit
>>> value by 31 bits is undefined behaviour [shiftTooManyBitsSigned]
>>>      while (!(__raw_readl(anatop_base + PLL_ARM) &
>> BM_PLL_ARM_LOCK))
>>>
>>> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
>>> Reported-by: kernel test robot <lkp@intel.com>
>>> ---
>>> Changes since V6:
>>> 	- improve the subject.
>>> ---
>>>  drivers/clk/imx/clk-imx6sl.c | 15 ++++++++-------
>>>  1 file changed, 8 insertions(+), 7 deletions(-)
>>>
>>> diff --git a/drivers/clk/imx/clk-imx6sl.c
>>> b/drivers/clk/imx/clk-imx6sl.c index 0f647d1..e69dba1 100644
>>> --- a/drivers/clk/imx/clk-imx6sl.c
>>> +++ b/drivers/clk/imx/clk-imx6sl.c
>>> @@ -3,6 +3,7 @@
>>>   * Copyright 2013-2014 Freescale Semiconductor, Inc.
>>>   */
>>>
>>> +#include <linux/bitfield.h>
>>
>> Hi,
>> I think you want
>> #include <linux/bits.h>
>>
>> for BIT() usage.
> 
> Actually, the linux/of.h already includes linux/bitops.h and linux/bitops.h includes
> linux/bits.h, so I will just drop linux/bitfield.h and send a V8.

or you could read Documentation/process/submit-checklist.rst,
where rule #1 says:

1) If you use a facility then #include the file that defines/declares
   that facility.  Don't depend on other header files pulling in ones
   that you use.
Anson Huang July 30, 2020, 1:14 a.m. UTC | #4
Hi, Randy


> Subject: Re: [PATCH V7 1/6] clk: imx6sl: Use BIT(x) to avoid shifting signed
> 32-bit value by 31 bits
> 
> On 7/29/20 4:51 PM, Anson Huang wrote:
> > Hi, Randy
> >
> >
> >> Subject: Re: [PATCH V7 1/6] clk: imx6sl: Use BIT(x) to avoid shifting
> >> signed 32-bit value by 31 bits
> >>
> >> On 7/29/20 7:48 AM, Anson Huang wrote:
> >>> Use readl_relaxed() instead of __raw_readl(), and use BIT(x) instead
> >>> of (1 << X) to fix below build warning reported by kernel test robot:
> >>>
> >>> drivers/clk/imx/clk-imx6sl.c:149:49: warning: Shifting signed 32-bit
> >>> value by 31 bits is undefined behaviour [shiftTooManyBitsSigned]
> >>>      while (!(__raw_readl(anatop_base + PLL_ARM) &
> >> BM_PLL_ARM_LOCK))
> >>>
> >>> Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
> >>> Reported-by: kernel test robot <lkp@intel.com>
> >>> ---
> >>> Changes since V6:
> >>> 	- improve the subject.
> >>> ---
> >>>  drivers/clk/imx/clk-imx6sl.c | 15 ++++++++-------
> >>>  1 file changed, 8 insertions(+), 7 deletions(-)
> >>>
> >>> diff --git a/drivers/clk/imx/clk-imx6sl.c
> >>> b/drivers/clk/imx/clk-imx6sl.c index 0f647d1..e69dba1 100644
> >>> --- a/drivers/clk/imx/clk-imx6sl.c
> >>> +++ b/drivers/clk/imx/clk-imx6sl.c
> >>> @@ -3,6 +3,7 @@
> >>>   * Copyright 2013-2014 Freescale Semiconductor, Inc.
> >>>   */
> >>>
> >>> +#include <linux/bitfield.h>
> >>
> >> Hi,
> >> I think you want
> >> #include <linux/bits.h>
> >>
> >> for BIT() usage.
> >
> > Actually, the linux/of.h already includes linux/bitops.h and
> > linux/bitops.h includes linux/bits.h, so I will just drop linux/bitfield.h and
> send a V8.
> 
> or you could read Documentation/process/submit-checklist.rst,
> where rule #1 says:
> 
> 1) If you use a facility then #include the file that defines/declares
>    that facility.  Don't depend on other header files pulling in ones
>    that you use.

Understood, while I search "BIT()" in clk driver, most of the drivers does NOT include
linux/bits.h even they use it.

But OK, I will send V9 to include it.

Thanks,
Anson
Arnd Bergmann July 30, 2020, 7:25 a.m. UTC | #5
On Thu, Jul 30, 2020 at 3:14 AM Anson Huang <anson.huang@nxp.com> wrote:
> > Subject: Re: [PATCH V7 1/6] clk: imx6sl: Use BIT(x) to avoid shifting signed
> > 32-bit value by 31 bits

> > or you could read Documentation/process/submit-checklist.rst,
> > where rule #1 says:
> >
> > 1) If you use a facility then #include the file that defines/declares
> >    that facility.  Don't depend on other header files pulling in ones
> >    that you use.
>
> Understood, while I search "BIT()" in clk driver, most of the drivers does NOT include
> linux/bits.h even they use it.
>
> But OK, I will send V9 to include it.

Ok, good.

I have a patch series that adds it to a lot of files. Note that linux/bitops.h
itself is a fairly big header with everything else that it includes, and it
is included almost everywhere indirectly.  When we change the other
headers to not require linux/bitops.h any more, everything that uses BIT()
needs to include linux/bits.h.

     Arnd
diff mbox series

Patch

diff --git a/drivers/clk/imx/clk-imx6sl.c b/drivers/clk/imx/clk-imx6sl.c
index 0f647d1..e69dba1 100644
--- a/drivers/clk/imx/clk-imx6sl.c
+++ b/drivers/clk/imx/clk-imx6sl.c
@@ -3,6 +3,7 @@ 
  * Copyright 2013-2014 Freescale Semiconductor, Inc.
  */
 
+#include <linux/bitfield.h>
 #include <linux/clk.h>
 #include <linux/clkdev.h>
 #include <linux/err.h>
@@ -14,19 +15,19 @@ 
 #include "clk.h"
 
 #define CCSR			0xc
-#define BM_CCSR_PLL1_SW_CLK_SEL	(1 << 2)
+#define BM_CCSR_PLL1_SW_CLK_SEL	BIT(2)
 #define CACRR			0x10
 #define CDHIPR			0x48
-#define BM_CDHIPR_ARM_PODF_BUSY	(1 << 16)
+#define BM_CDHIPR_ARM_PODF_BUSY	BIT(16)
 #define ARM_WAIT_DIV_396M	2
 #define ARM_WAIT_DIV_792M	4
 #define ARM_WAIT_DIV_996M	6
 
 #define PLL_ARM			0x0
-#define BM_PLL_ARM_DIV_SELECT	(0x7f << 0)
-#define BM_PLL_ARM_POWERDOWN	(1 << 12)
-#define BM_PLL_ARM_ENABLE	(1 << 13)
-#define BM_PLL_ARM_LOCK		(1 << 31)
+#define BM_PLL_ARM_DIV_SELECT	0x7f
+#define BM_PLL_ARM_POWERDOWN	BIT(12)
+#define BM_PLL_ARM_ENABLE	BIT(13)
+#define BM_PLL_ARM_LOCK		BIT(31)
 #define PLL_ARM_DIV_792M	66
 
 static const char *step_sels[]		= { "osc", "pll2_pfd2", };
@@ -145,7 +146,7 @@  static void imx6sl_enable_pll_arm(bool enable)
 		val |= BM_PLL_ARM_ENABLE;
 		val &= ~BM_PLL_ARM_POWERDOWN;
 		writel_relaxed(val, anatop_base + PLL_ARM);
-		while (!(__raw_readl(anatop_base + PLL_ARM) & BM_PLL_ARM_LOCK))
+		while (!(readl_relaxed(anatop_base + PLL_ARM) & BM_PLL_ARM_LOCK))
 			;
 	} else {
 		 writel_relaxed(saved_pll_arm, anatop_base + PLL_ARM);