[PATCH] fpga fr br: fix warning for unexpected version number

[PATCH] fpga fr br: fix warning for unexpected version number

[matthew.gerlach]

From: Matthew Gerlach <matthew.gerlach@linux.intel.com>

The value in the version register of the altera freeze bridge
controller changed from the beta value of 2 to the
value of 0xad000003 in the official release of the IP.
This patch supports the old and new version numbers
without printing an warning.

Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
---
 drivers/fpga/altera-freeze-bridge.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/fpga/altera-freeze-bridge.c b/drivers/fpga/altera-freeze-bridge.c
index 8dcd9fb..bdfd5eb 100644
--- a/drivers/fpga/altera-freeze-bridge.c
+++ b/drivers/fpga/altera-freeze-bridge.c
@@ -28,6 +28,7 @@
 #define FREEZE_CSR_REG_VERSION			12
 
 #define FREEZE_CSR_SUPPORTED_VERSION		2
+#define FREEZE_CSR_OFFICIAL_VERSION		0xad000003
 
 #define FREEZE_CSR_STATUS_FREEZE_REQ_DONE	BIT(0)
 #define FREEZE_CSR_STATUS_UNFREEZE_REQ_DONE	BIT(1)
@@ -241,10 +242,12 @@ static int altera_freeze_br_probe(struct platform_device *pdev)
 		priv->enable = 1;
 
 	revision = readl(priv->base_addr + FREEZE_CSR_REG_VERSION);
-	if (revision != FREEZE_CSR_SUPPORTED_VERSION)
+	if ((revision != FREEZE_CSR_SUPPORTED_VERSION) &&
+	    (revision != FREEZE_CSR_OFFICIAL_VERSION))
 		dev_warn(dev,
-			 "%s Freeze Controller unexpected revision %d != %d\n",
-			 __func__, revision, FREEZE_CSR_SUPPORTED_VERSION);
+			 "%s unexpected revision 0x%x != 0x%x != 0x%x\n",
+			 __func__, revision, FREEZE_CSR_SUPPORTED_VERSION,
+			 FREEZE_CSR_OFFICIAL_VERSION);
 
 	return fpga_bridge_register(dev, FREEZE_BRIDGE_NAME,
 				    &altera_freeze_br_br_ops, priv);
-- 
2.7.4

Re: [PATCH] fpga fr br: fix warning for unexpected version number

[Moritz Fischer]

Hi Matthew,

On Wed, Apr 5, 2017 at 12:05 PM,  <matthew.gerlach@linux.intel.com> wrote:
> From: Matthew Gerlach <matthew.gerlach@linux.intel.com>
>
> The value in the version register of the altera freeze bridge
> controller changed from the beta value of 2 to the
> value of 0xad000003 in the official release of the IP.
> This patch supports the old and new version numbers
> without printing an warning.
>
> Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
> ---
>  drivers/fpga/altera-freeze-bridge.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/fpga/altera-freeze-bridge.c b/drivers/fpga/altera-freeze-bridge.c
> index 8dcd9fb..bdfd5eb 100644
> --- a/drivers/fpga/altera-freeze-bridge.c
> +++ b/drivers/fpga/altera-freeze-bridge.c
> @@ -28,6 +28,7 @@
>  #define FREEZE_CSR_REG_VERSION                 12
>
>  #define FREEZE_CSR_SUPPORTED_VERSION           2
> +#define FREEZE_CSR_OFFICIAL_VERSION            0xad000003
>
>  #define FREEZE_CSR_STATUS_FREEZE_REQ_DONE      BIT(0)
>  #define FREEZE_CSR_STATUS_UNFREEZE_REQ_DONE    BIT(1)
> @@ -241,10 +242,12 @@ static int altera_freeze_br_probe(struct platform_device *pdev)
>                 priv->enable = 1;
>
>         revision = readl(priv->base_addr + FREEZE_CSR_REG_VERSION);
> -       if (revision != FREEZE_CSR_SUPPORTED_VERSION)
> +       if ((revision != FREEZE_CSR_SUPPORTED_VERSION) &&
> +           (revision != FREEZE_CSR_OFFICIAL_VERSION))
>                 dev_warn(dev,
> -                        "%s Freeze Controller unexpected revision %d != %d\n",
> -                        __func__, revision, FREEZE_CSR_SUPPORTED_VERSION);
> +                        "%s unexpected revision 0x%x != 0x%x != 0x%x\n",
> +                        __func__, revision, FREEZE_CSR_SUPPORTED_VERSION,
> +                        FREEZE_CSR_OFFICIAL_VERSION);

Maybe you actually wanna bail out if you read a random other value
instead of what you
expect instead of printing a warning.
>
>         return fpga_bridge_register(dev, FREEZE_BRIDGE_NAME,
>                                     &altera_freeze_br_br_ops, priv);
> --
> 2.7.4
>

Cheers,

Moritz

Re: [PATCH] fpga fr br: fix warning for unexpected version number

[matthew.gerlach]

On Wed, 5 Apr 2017, Moritz Fischer wrote:

> Hi Matthew,
>

Hi Moritz,


> On Wed, Apr 5, 2017 at 12:05 PM,  <matthew.gerlach@linux.intel.com> wrote:
>> From: Matthew Gerlach <matthew.gerlach@linux.intel.com>
>>
>> The value in the version register of the altera freeze bridge
>> controller changed from the beta value of 2 to the
>> value of 0xad000003 in the official release of the IP.
>> This patch supports the old and new version numbers
>> without printing an warning.
>>
>> Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
>> ---
>>  drivers/fpga/altera-freeze-bridge.c | 9 ++++++---
>>  1 file changed, 6 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/fpga/altera-freeze-bridge.c b/drivers/fpga/altera-freeze-bridge.c
>> index 8dcd9fb..bdfd5eb 100644
>> --- a/drivers/fpga/altera-freeze-bridge.c
>> +++ b/drivers/fpga/altera-freeze-bridge.c
>> @@ -28,6 +28,7 @@
>>  #define FREEZE_CSR_REG_VERSION                 12
>>
>>  #define FREEZE_CSR_SUPPORTED_VERSION           2
>> +#define FREEZE_CSR_OFFICIAL_VERSION            0xad000003
>>
>>  #define FREEZE_CSR_STATUS_FREEZE_REQ_DONE      BIT(0)
>>  #define FREEZE_CSR_STATUS_UNFREEZE_REQ_DONE    BIT(1)
>> @@ -241,10 +242,12 @@ static int altera_freeze_br_probe(struct platform_device *pdev)
>>                 priv->enable = 1;
>>
>>         revision = readl(priv->base_addr + FREEZE_CSR_REG_VERSION);
>> -       if (revision != FREEZE_CSR_SUPPORTED_VERSION)
>> +       if ((revision != FREEZE_CSR_SUPPORTED_VERSION) &&
>> +           (revision != FREEZE_CSR_OFFICIAL_VERSION))
>>                 dev_warn(dev,
>> -                        "%s Freeze Controller unexpected revision %d != %d\n",
>> -                        __func__, revision, FREEZE_CSR_SUPPORTED_VERSION);
>> +                        "%s unexpected revision 0x%x != 0x%x != 0x%x\n",
>> +                        __func__, revision, FREEZE_CSR_SUPPORTED_VERSION,
>> +                        FREEZE_CSR_OFFICIAL_VERSION);
>
> Maybe you actually wanna bail out if you read a random other value
> instead of what you
> expect instead of printing a warning.

I thought about making it an error if the version didn't match, but it was 
a dev_warn() before and that allowed folks to use the "old" driver with 
the new IP version.

>>
>>         return fpga_bridge_register(dev, FREEZE_BRIDGE_NAME,
>>                                     &altera_freeze_br_br_ops, priv);
>> --
>> 2.7.4
>>
>
> Cheers,
>
> Moritz
>

Re: [PATCH] fpga fr br: fix warning for unexpected version number

[Moritz Fischer]

Hi Matthew,

On Wed, Apr 5, 2017 at 3:25 PM,  <matthew.gerlach@linux.intel.com> wrote:

>> Maybe you actually wanna bail out if you read a random other value
>> instead of what you
>> expect instead of printing a warning.
>
>
> I thought about making it an error if the version didn't match, but it was a
> dev_warn() before and that allowed folks to use the "old" driver with the
> new IP version.

Or some random other piece of logic in the FPGA that happens to be mapped
to that address ;-)

I agree we should've probably caught this in the initial review, but maybe we
should change it.

Cheers,

Moritz