Re: [PATCH v2 2/3] ntb_transport: Check the number of spads the hardware supports

[Jon Mason]

On Tue, Jun 7, 2016 at 1:24 PM, Jiang, Dave <dave.jiang@xxxxxxxxx> wrote:
> On Tue, 2016-06-07 at 11:20 -0600, Logan Gunthorpe wrote:
>> I'm working on hardware that currently has a limited number of
>> scratchpad registers and ntb_ndev fails with no clue as to why. I
>> feel it is better to fail early and provide a reasonable error
>> message
>> then to fail later on.
>>
>> The same is done to ntb_perf, but it doesn't currently require enough
>> spads to actually fail. I've also removed the unused SPAD_MSG and
>> SPAD_ACK enums so that MAX_SPAD accurately reflects the number of
>> spads used.
>>
>> Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
>
> Acked-by: Dave Jiang <dave.jiang@xxxxxxxxx>

Added to the ntb-next branch.

thanks,
Jon

>> ---
>>  drivers/ntb/ntb_transport.c | 9 +++++++--
>>  drivers/ntb/test/ntb_perf.c | 8 ++++++--
>>  2 files changed, 13 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/ntb/ntb_transport.c
>> b/drivers/ntb/ntb_transport.c
>> index 2ef9d913..6d9940a 100644
>> --- a/drivers/ntb/ntb_transport.c
>> +++ b/drivers/ntb/ntb_transport.c
>> @@ -1037,6 +1037,13 @@ static int ntb_transport_probe(struct
>> ntb_client *self, struct ntb_dev *ndev)
>>       int node;
>>       int rc, i;
>>
>> +     mw_count = ntb_mw_count(ndev);
>> +     if (ntb_spad_count(ndev) < (NUM_MWS + 1 + mw_count * 2)) {
>> +             dev_err(&ndev->dev, "Not enough scratch pad
>> registers for %s",
>> +                     NTB_TRANSPORT_NAME);
>> +             return -EIO;
>> +     }
>> +
>>       if (ntb_db_is_unsafe(ndev))
>>               dev_dbg(&ndev->dev,
>>                       "doorbell is unsafe, proceed anyway...\n");
>> @@ -1052,8 +1059,6 @@ static int ntb_transport_probe(struct
>> ntb_client *self, struct ntb_dev *ndev)
>>
>>       nt->ndev = ndev;
>>
>> -     mw_count = ntb_mw_count(ndev);
>> -
>>       nt->mw_count = mw_count;
>>
>>       nt->mw_vec = kzalloc_node(mw_count * sizeof(*nt->mw_vec),
>> diff --git a/drivers/ntb/test/ntb_perf.c
>> b/drivers/ntb/test/ntb_perf.c
>> index 30635c8..4368519 100644
>> --- a/drivers/ntb/test/ntb_perf.c
>> +++ b/drivers/ntb/test/ntb_perf.c
>> @@ -143,8 +143,6 @@ enum {
>>       VERSION = 0,
>>       MW_SZ_HIGH,
>>       MW_SZ_LOW,
>> -     SPAD_MSG,
>> -     SPAD_ACK,
>>       MAX_SPAD
>>  };
>>
>> @@ -696,6 +694,12 @@ static int perf_probe(struct ntb_client *client,
>> struct ntb_dev *ntb)
>>       int node;
>>       int rc = 0;
>>
>> +     if (ntb_spad_count(ntb) < MAX_SPAD) {
>> +             dev_err(&ntb->dev, "Not enough scratch pad registers
>> for %s",
>> +                     DRIVER_NAME);
>> +             return -EIO;
>> +     }
>> +
>>       node = dev_to_node(&pdev->dev);
>>
>>       perf = kzalloc_node(sizeof(*perf), GFP_KERNEL, node);
>> --
>> 2.1.4
>>
>
> --
> You received this message because you are subscribed to the Google Groups "linux-ntb" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to linux-ntb+unsubscribe@xxxxxxxxxxxxxxxxx
> To post to this group, send email to linux-ntb@xxxxxxxxxxxxxxxxx
> To view this discussion on the web visit https://groups.google.com/d/msgid/linux-ntb/1465320253.16234.176.camel%40intel.com.
> For more options, visit https://groups.google.com/d/optout.