> -----Original Message----- > From: James Bottomley [mailto:James.Bottomley@xxxxxxx] > Sent: Friday, November 13, 2009 8:24 PM > To: Desai, Kashyap > Cc: linux-scsi@xxxxxxxxxxxxxxx; Moore, Eric; Prakash, Sathya > Subject: Re: [PATCH] mpt2sas : Enable TLR for SSP TAPE drives > > On Fri, 2009-11-13 at 13:56 +0530, Kashyap, Desai wrote: > > The driver is sending vpd page 0, to get a list of supported pages. Then > it > > will traverse the list searching for page 0x90. when page 0x90 is > present, > > the driver will enable the TLR logic for Tape devices only. The TLR > logic > > will enable the TLR bits in the SCSI_IO for every request. If there is a > > response with MPI2_SCSITASKMGMT_RSP_INVALID_FRAME, the driver will turn > off > > the TLR logic. > > This is applicable to all SAS drivers, isn't it? So it should be in the > sas transport class and we should be figuring out how to add it to all > SAS drivers, shouldn't we? > > James > Agree. Nice to have it in transport layer. In that case, we have to add *tlr_enabled* field in *struct scsi_device*. Currently we are using "sdev->hostdata" to store tlr flags.(this can be replaced by above proposed field in scs_device) We can add functions like /*Enable*/ Void sas_enable_tlr(struct scsi_device *sdev) /*Disable*/ Void sas_disable_tlr(struct scsi_device *sdev) /*Check*/ int sas_check_tlr(struct scsi_device *sdev) Caller can take care of checking IOC capabilities of supporting TLR at HBA level and they can call sas_enable_tlr to enable TLR for particular drive. Suggestion? Kashyap -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
