On 01/27/15 23:11, Tyrel Datwyler wrote:
> On 01/23/2015 04:10 AM, Bart Van Assche wrote:
>> Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
>> Cc: Brian King <brking@xxxxxxxxxxxxxxxxxx>
>> Cc: Nathan Fontenot <nfont@xxxxxxxxxxxxxxxxxx>
>> ---
>> drivers/scsi/ibmvscsi/ibmvscsi.c | 10 ++++++----
>> 1 file changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
>> index acea5d6..cf26b33 100644
>> --- a/drivers/scsi/ibmvscsi/ibmvscsi.c
>> +++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
>> @@ -765,16 +765,18 @@ static int map_data_for_srp_cmd(struct scsi_cmnd *cmd,
>> struct srp_event_struct *evt_struct,
>> struct srp_cmd *srp_cmd, struct device *dev)
>> {
>> + if (scsi_bidi_cmnd(cmd)) {
>> + sdev_printk(KERN_ERR, cmd->device,
>> + "Bidirectional commands are not yet supported\n");
>> + return 0;
>> + }
>> +
>
> Is there a particular problem this solves, or is this simply a change to
> use the bidi API in place of checking sc_data_direction for
> DMA_BIDIRECTIONAL?
>
> -Tyrel
>
>> switch (cmd->sc_data_direction) {
>> case DMA_FROM_DEVICE:
>> case DMA_TO_DEVICE:
>> break;
>> case DMA_NONE:
>> return 1;
>> - case DMA_BIDIRECTIONAL:
>> - sdev_printk(KERN_ERR, cmd->device,
>> - "Can't map DMA_BIDIRECTIONAL to read/write\n");
>> - return 0;
>> default:
>> sdev_printk(KERN_ERR, cmd->device,
>> "Unknown data direction 0x%02x; can't map!\n",
>>
Hello Tyrel,
Since the ibmvscsi driver does not set QUEUE_FLAG_BIDI neither the code
under "case DMA_BIDIRECTIONAL" nor the code under "if
(scsi_bidi_cmnd(cmd))" is ever executed. The only reason why I proposed
this change is to avoid that an author of another SCSI LLD driver would
use the code that compares sc_data_direction with DMA_BIDIRECTIONAL as
an example.
BTW, had you already noticed that Christoph Hellwig proposed to modify
the SCSI core such that sc_data_direction is set to DMA_BIDIRECTIONAL
for bidi commands ? I'd like to rework this patch series accordingly.
With that approach no changes are necessary in the ibmvscsi driver.
Bart.
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