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[PATCH v3] serial: 8250_dw: fix wrong logic in dw8250_check_lcr()

Started byKefeng Wang <wangkefeng.wang@huawei.com>
First post2016-04-05 05:40 +0200
Last post2016-04-07 10:40 +0200
Articles 6 — 3 participants

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  [PATCH v3] serial: 8250_dw: fix wrong logic in dw8250_check_lcr() Kefeng Wang <wangkefeng.wang@huawei.com> - 2016-04-05 05:40 +0200
    Re: [PATCH v3] serial: 8250_dw: fix wrong logic in dw8250_check_lcr() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-05 06:10 +0200
      Re: [PATCH v3] serial: 8250_dw: fix wrong logic in dw8250_check_lcr() Kefeng Wang <wangkefeng.wang@huawei.com> - 2016-04-05 07:00 +0200
    [PATCH v4] serial: 8250_dw: fix wrong logic in dw8250_check_lcr() Kefeng Wang <wangkefeng.wang@huawei.com> - 2016-04-05 08:00 +0200
      Re: [PATCH v4] serial: 8250_dw: fix wrong logic in  dw8250_check_lcr() Andy Shevchenko <andriy.shevchenko@linux.intel.com> - 2016-04-05 12:50 +0200
        Re: [PATCH v4] serial: 8250_dw: fix wrong logic in dw8250_check_lcr() Kefeng Wang <wangkefeng.wang@huawei.com> - 2016-04-07 10:40 +0200

#1371167 — [PATCH v3] serial: 8250_dw: fix wrong logic in dw8250_check_lcr()

FromKefeng Wang <wangkefeng.wang@huawei.com>
Date2016-04-05 05:40 +0200
Subject[PATCH v3] serial: 8250_dw: fix wrong logic in dw8250_check_lcr()
Message-ID<rkq0p-59v-13@gated-at.bofh.it>
Commit cdcea058e510 ("serial: 8250_dw: Avoid serial_outx code duplicate
with new dw8250_check_lcr()") introduce a wrong logic when write val to
LCR reg. When CONFIG_64BIT enabled, __raw_writeq is used unconditionally.

The __raw_readq/__raw_writeq is introduced by commit bca2092d7897 ("serial:
8250_dw: Use 64-bit access for OCTEON.") for OCTEON, so for !PORT_OCTEON,
we better to use coincident write func.

Fixes: cdcea058e510("serial: 8250_dw: Avoid serial_outx code duplicate with new dw8250_check_lcr()")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---
Keep #ifdef CONFIG_64BIT to ensure it built under arch lacking readq/writeq.

 drivers/tty/serial/8250/8250_dw.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index a3fb95d..47d1f3e 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -104,15 +104,16 @@ static void dw8250_check_lcr(struct uart_port *p, int value)
 		dw8250_force_idle(p);
 
 #ifdef CONFIG_64BIT
-		__raw_writeq(value & 0xff, offset);
-#else
+		if (p->type == PORT_OCTEON)
+			__raw_writeq(value & 0xff, offset);
+		else
+#endif
 		if (p->iotype == UPIO_MEM32)
 			writel(value, offset);
 		else if (p->iotype == UPIO_MEM32BE)
 			iowrite32be(value, offset);
 		else
 			writeb(value, offset);
-#endif
 	}
 	/*
 	 * FIXME: this deadlocks if port->lock is already held
-- 
2.6.0.GIT

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#1371182

FromGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Date2016-04-05 06:10 +0200
Message-ID<rkqts-5H7-1@gated-at.bofh.it>
In reply to#1371167
On Tue, Apr 05, 2016 at 11:32:46AM +0800, Kefeng Wang wrote:
> Commit cdcea058e510 ("serial: 8250_dw: Avoid serial_outx code duplicate
> with new dw8250_check_lcr()") introduce a wrong logic when write val to
> LCR reg. When CONFIG_64BIT enabled, __raw_writeq is used unconditionally.
> 
> The __raw_readq/__raw_writeq is introduced by commit bca2092d7897 ("serial:
> 8250_dw: Use 64-bit access for OCTEON.") for OCTEON, so for !PORT_OCTEON,
> we better to use coincident write func.
> 
> Fixes: cdcea058e510("serial: 8250_dw: Avoid serial_outx code duplicate with new dw8250_check_lcr()")
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
> Keep #ifdef CONFIG_64BIT to ensure it built under arch lacking readq/writeq.
> 
>  drivers/tty/serial/8250/8250_dw.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)

What changed between all of these versions?  Always document that below
the --- line otherwise I think they are all the same and I'll just
delete them all :)

v4 please.

thanks,

greg k-h

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#1371204

FromKefeng Wang <wangkefeng.wang@huawei.com>
Date2016-04-05 07:00 +0200
Message-ID<rkrfR-652-31@gated-at.bofh.it>
In reply to#1371182

On 2016/4/5 12:02, Greg Kroah-Hartman wrote:
> On Tue, Apr 05, 2016 at 11:32:46AM +0800, Kefeng Wang wrote:
>> Commit cdcea058e510 ("serial: 8250_dw: Avoid serial_outx code duplicate
>> with new dw8250_check_lcr()") introduce a wrong logic when write val to
>> LCR reg. When CONFIG_64BIT enabled, __raw_writeq is used unconditionally.
>>
>> The __raw_readq/__raw_writeq is introduced by commit bca2092d7897 ("serial:
>> 8250_dw: Use 64-bit access for OCTEON.") for OCTEON, so for !PORT_OCTEON,
>> we better to use coincident write func.
>>
>> Fixes: cdcea058e510("serial: 8250_dw: Avoid serial_outx code duplicate with new dw8250_check_lcr()")
>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
>> ---
>> Keep #ifdef CONFIG_64BIT to ensure it built under arch lacking readq/writeq.
>>
>>  drivers/tty/serial/8250/8250_dw.c | 7 ++++---
>>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> What changed between all of these versions?  Always document that below
> the --- line otherwise I think they are all the same and I'll just
> delete them all :)

Thanks for your guidance, will add log if with different versions to show what changes.
> 
> v4 please.

Ok, thanks again.

> 
> thanks,
> 
> greg k-h
> 
> .
>

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#1371240 — [PATCH v4] serial: 8250_dw: fix wrong logic in dw8250_check_lcr()

FromKefeng Wang <wangkefeng.wang@huawei.com>
Date2016-04-05 08:00 +0200
Subject[PATCH v4] serial: 8250_dw: fix wrong logic in dw8250_check_lcr()
Message-ID<rksbV-6Tc-23@gated-at.bofh.it>
In reply to#1371167
Commit cdcea058e510 ("serial: 8250_dw: Avoid serial_outx code duplicate
with new dw8250_check_lcr()") introduce a wrong logic when write val to
LCR reg. When CONFIG_64BIT enabled, __raw_writeq is used unconditionally.

The __raw_readq/__raw_writeq is introduced by commit bca2092d7897 ("serial:
8250_dw: Use 64-bit access for OCTEON.") for OCTEON, so for !PORT_OCTEON,
we better to use coincident write func.

Fixes: cdcea058e510("serial: 8250_dw: Avoid serial_outx code duplicate with new dw8250_check_lcr()")
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
---

Changes since v3:
- Add patch change log, suggested by Greg Kroah-Hartman.
Changes since v2:
- Add #ifdef CONFIG_64BIT back, ensure it can be built under configuration lacking readq/writeq.
Changes since v1:
- Repace '#ifdef CONFIG_64BIT' with IS_ENABLED(CONFIG_64BIT).
- Enrich patch log, and add Fixes tag.
  

 drivers/tty/serial/8250/8250_dw.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index a3fb95d..47d1f3e 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -104,15 +104,16 @@ static void dw8250_check_lcr(struct uart_port *p, int value)
 		dw8250_force_idle(p);
 
 #ifdef CONFIG_64BIT
-		__raw_writeq(value & 0xff, offset);
-#else
+		if (p->type == PORT_OCTEON)
+			__raw_writeq(value & 0xff, offset);
+		else
+#endif
 		if (p->iotype == UPIO_MEM32)
 			writel(value, offset);
 		else if (p->iotype == UPIO_MEM32BE)
 			iowrite32be(value, offset);
 		else
 			writeb(value, offset);
-#endif
 	}
 	/*
 	 * FIXME: this deadlocks if port->lock is already held
-- 
2.6.0.GIT

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#1371385 — Re: [PATCH v4] serial: 8250_dw: fix wrong logic in dw8250_check_lcr()

FromAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Date2016-04-05 12:50 +0200
SubjectRe: [PATCH v4] serial: 8250_dw: fix wrong logic in dw8250_check_lcr()
Message-ID<rkwIy-1OI-17@gated-at.bofh.it>
In reply to#1371240
On Tue, 2016-04-05 at 13:53 +0800, Kefeng Wang wrote:
> Commit cdcea058e510 ("serial: 8250_dw: Avoid serial_outx code
> duplicate
> with new dw8250_check_lcr()") introduce a wrong logic when write val
> to
> LCR reg. When CONFIG_64BIT enabled, __raw_writeq is used
> unconditionally.
> 
> The __raw_readq/__raw_writeq is introduced by commit bca2092d7897
> ("serial:
> 8250_dw: Use 64-bit access for OCTEON.") for OCTEON, so for
> !PORT_OCTEON,
> we better to use coincident write func.
> 
> Fixes: cdcea058e510("serial: 8250_dw: Avoid serial_outx code
> duplicate with new dw8250_check_lcr()")
> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> ---
> 
> Changes since v3:
> - Add patch change log, suggested by Greg Kroah-Hartman.
> Changes since v2:
> - Add #ifdef CONFIG_64BIT back, ensure it can be built under 

Oh, true. Since it's a native IO we can't use writeq() helper from io-
64-nonatomic-*. 

> configuration lacking readq/writeq.
> Changes since v1:
> - Repace '#ifdef CONFIG_64BIT' with IS_ENABLED(CONFIG_64BIT).
> - Enrich patch log, and add Fixes tag.
>   
> 
>  drivers/tty/serial/8250/8250_dw.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/tty/serial/8250/8250_dw.c
> b/drivers/tty/serial/8250/8250_dw.c
> index a3fb95d..47d1f3e 100644
> --- a/drivers/tty/serial/8250/8250_dw.c
> +++ b/drivers/tty/serial/8250/8250_dw.c
> @@ -104,15 +104,16 @@ static void dw8250_check_lcr(struct uart_port
> *p, int value)
>  		dw8250_force_idle(p);
>  
>  #ifdef CONFIG_64BIT
> -		__raw_writeq(value & 0xff, offset);
> -#else
> +		if (p->type == PORT_OCTEON)
> +			__raw_writeq(value & 0xff, offset);
> +		else
> +#endif
>  		if (p->iotype == UPIO_MEM32)
>  			writel(value, offset);
>  		else if (p->iotype == UPIO_MEM32BE)
>  			iowrite32be(value, offset);
>  		else
>  			writeb(value, offset);
> -#endif

So, this changes logic to write the value on any 64 platform, using
different (non-64-bit) accessors, so, the case to fix is
actually "64BIT && !PORT_OCTEON". Perhaps commit message should be
amended to point that clearly.

>  	}
>  	/*
>  	 * FIXME: this deadlocks if port->lock is already held

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy

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#1373158 — Re: [PATCH v4] serial: 8250_dw: fix wrong logic in dw8250_check_lcr()

FromKefeng Wang <wangkefeng.wang@huawei.com>
Date2016-04-07 10:40 +0200
SubjectRe: [PATCH v4] serial: 8250_dw: fix wrong logic in dw8250_check_lcr()
Message-ID<rldDQ-15J-9@gated-at.bofh.it>
In reply to#1371385

On 2016/4/5 18:50, Andy Shevchenko wrote:
> On Tue, 2016-04-05 at 13:53 +0800, Kefeng Wang wrote:
>> Commit cdcea058e510 ("serial: 8250_dw: Avoid serial_outx code
>> duplicate
>> with new dw8250_check_lcr()") introduce a wrong logic when write val
>> to
>> LCR reg. When CONFIG_64BIT enabled, __raw_writeq is used
>> unconditionally.
>>
>> The __raw_readq/__raw_writeq is introduced by commit bca2092d7897
>> ("serial:
>> 8250_dw: Use 64-bit access for OCTEON.") for OCTEON, so for
>> !PORT_OCTEON,
>> we better to use coincident write func.
>>
>> Fixes: cdcea058e510("serial: 8250_dw: Avoid serial_outx code
>> duplicate with new dw8250_check_lcr()")
>> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
>> ---
>>
>> Changes since v3:
>> - Add patch change log, suggested by Greg Kroah-Hartman.
>> Changes since v2:
>> - Add #ifdef CONFIG_64BIT back, ensure it can be built under 
> 
> Oh, true. Since it's a native IO we can't use writeq() helper from io-
> 64-nonatomic-*. 
> 
>> configuration lacking readq/writeq.
>> Changes since v1:
>> - Repace '#ifdef CONFIG_64BIT' with IS_ENABLED(CONFIG_64BIT).
>> - Enrich patch log, and add Fixes tag.
[...]
> 
> So, this changes logic to write the value on any 64 platform, using
> different (non-64-bit) accessors, so, the case to fix is
> actually "64BIT && !PORT_OCTEON". Perhaps commit message should be
> amended to point that clearly.

Yes, it's more clear. thanks for review and point it out.

To Greg, should I resend it or can you help me to change the patch log when you merge it. Thanks.

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