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authorSreekanth Reddy <sreekanth.reddy@broadcom.com>2020-10-27 14:08:41 +0100
committerMartin K. Petersen <martin.petersen@oracle.com>2020-11-05 00:42:24 +0100
commita5e99fda017218516d3c66bec5ed346283ae722b (patch)
tree089a226ff657f00e868829c2d83eefb0b1f1c176 /drivers/scsi/script_asm.pl
parentscsi: mpt3sas: Get sas_device objects using device's rphy (diff)
downloadlinux-a5e99fda017218516d3c66bec5ed346283ae722b.tar.xz
linux-a5e99fda017218516d3c66bec5ed346283ae722b.zip
scsi: mpt3sas: Update hba_port objects after host reset
During host reset there is a chance that the Port number allocated by the firmware for the attached devices may change. Also, it may be possible that some HBA phy's can go down/come up after reset. As a result, the driver can't just trust the HBA Port table that it has populated before host reset as valid. Instead it has to update the HBA Port table in such a way that it shouldn't disturb the drives which are still accessible even after host reset. Use the following algorithm to update the HBA Port table during host reset: I. After host reset operation and before marking the devices as responding/non-responding, create a temporary Port table called "New Port table" by parsing each of the HBA phy's Phy data info read from SAS IOUnit Page0: a. Check whether Phy's negotiated link rate is greater than 1.5Gbps, if not go to next Phy; b. Get the SAS Address of the attached device; c. Create a new entry in the "New Port table" with SAS Address field filled with attached device's SAS Address, port number with Phy's Port number (read from SAS IOUnit Page0) and enable bit in the 'Phy mask' field corresponding to current Phy number. New entry is created only if the driver can't find an entry in the "New Port table" which matches with attached device 'SAS Address' & 'Port Number'. If it finds an entry with matches with attached device 'SAS Address' & 'Port Number' then the driver takes that matched entry and will enable current Phy number bit in the 'Phy mask' field; d. After parsing all the HBA phy's info, the driver will have complete Port table info in "New Port table". II. Mark all the existing sas_device & sas_expander device structures as 'dirty'. III. Mark each entry of the HBA Port lists as 'dirty'. IV. Take each entry from 'New Port table' one by one and check whether the entry has any corresponding matched entry (which is marked as 'dirty') in the HBA Port table or not. While looking for a corresponding matched entry, look for matched entry in the sequence from top row to bottom row listed in the following table. If you find any matched entry (according to any of the rules tabulated below) then perform the action mentioned in the 'Action' column in that matched rule. =========================================================================== |Search |SAS | Phy Mask | Port | Possibilities| Action | |every |Address | or | Number | | required | |entry |matched?| subset of| matched?| | | |in below| | phy mask | | | | |sequence| | matched? | | | | =========================================================================== | 1 |matched | matched | matched | nothing |* unmark HBA port | | | | | | changed |table entry as | | | | | | |dirty | --------------------------------------------------------------------------- | 2 |matched | matched | not | port number |* Update port | | | | | matched | is changed |number in the | | | | | | |matched port table | | | | | | |entry | | | | | | |* unmask HBA port | | | | | | |table entry as | | | | | | |dirty | --------------------------------------------------------------------------- | 3.a |matched | subset of| matched |some phys |* Add these new | | | | phy mask | (or) |might have |phys to current | | | | matched | not |enabled which |port in STL | | | | | matched |are previously|* Update phy mask | | | | | (but |disabled |field in HBA's port| | | | | first | |table's matched | | | | | look for| |entry, | | | | | matched | |* Update port | | | | | one) | |number in the | | | | | | |matched port | | | | | | |table entry (if | | | | | | |port number is | | | | | | |changed), | | | | | | |* Unmask HBA port | | | | | | |table entry as | | | | | | |dirty | --------------------------------------------------------------------------- | 3.b |matched | subset of| matched |some phys |*Remove these phys | | | | phy mask | (or) |might have |from current port | | | | matched | not |disabled which|in STL | | | | | matched |are previously|* Update phy mask | | | | | (but |enabled |field in HBA's port| | | | | first | |tables's matched | | | | | look for| |entry, | | | | | matched | |*Update port number| | | | | one) | |in the matched port| | | | | | |table entry (if | | | | | | |port number is | | | | | | |changed), | | | | | | |* Unmask HBA port | | | | | | |table entry as | | | | | | |dirty | --------------------------------------------------------------------------- | 4 |matched | not | matched |A cable |*Remove old phys & | | | | matched | (or) |attached to an|new phys to current| | | | | not |expander is |port in STL | | | | | matched |changed to |* Update phy mask | | | | | |another HBA |field in HBA's port| | | | | |port during |tables's matched | | | | | |reset |entry, | | | | | | |*Update port number| | | | | | |in the matched port| | | | | | |table entry (if | | | | | | |port number is | | | | | | |changed), | | | | | | |* Unmask HBA port | | | | | | |table entry as | | | | | | |dirty | --------------------------------------------------------------------------- V. Delete the hba_port objects which are still marked as dirty. Link: https://lore.kernel.org/r/20201027130847.9962-9-sreekanth.reddy@broadcom.com Reported-by: kernel test robot <lkp@intel.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'drivers/scsi/script_asm.pl')
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