| Message ID | 1476954305-576-5-git-send-email-sumit.saxena@broadcom.com (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
On 10/20/2016 05:05 AM, Sumit Saxena wrote: > From previous patch we have below changes in v2 - > 1. Updated change log. Provided more detail in change log. > 2. Agreed to remove module parameter. If we remove module parameter, we > can ask customer to disable WCE on drive to get similar impact. > 3. Always Send SYNCHRONIZE_CACHE for JBOD (non Raid) Device to Firmware. Just a note - the user can disable sending the synchronize cache settings by mount time options with a file system (nobarrier) or for raw devices, overriding cache_type. This should never be required unless the target device has some quirk that does not allow it to handle synchronize_cache correctly. Regards, Ric -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, 2016-10-20 at 02:05 -0700, Sumit Saxena wrote: > From previous patch we have below changes in v2 - > 1. Updated change log. Provided more detail in change log. > 2. Agreed to remove module parameter. If we remove module parameter, > we > can ask customer to disable WCE on drive to get similar impact. > 3. Always Send SYNCHRONIZE_CACHE for JBOD (non Raid) Device to > Firmware. > > Current megaraid_sas driver returns SYNCHRONIZE_CACHE(related to > Drive > Cache) command back to SCSI layer without sending it down to > firmware as > firmware supposed to take care of flushing disk cache for all drives > belongs to Virtual Disk at the time of system reboot/shutdown. > > We evaluate and understood that for Raid Volume, why driver should > not > send SYNC_CACHE command to the Firmware. > There may be a some reason in past, but now it looks to be not > required and > we have fixed this issue as part of this patch. > > Commit- " 02b01e0 [SCSI] megaraid_sas: return sync cache call with > success" > added the code in driver to return SYNCHRONIZE_CACHE without sending > it to > firmware back in 2007. Earlier MR was mainly for Virtual Disk, > so same code continue for JBOD as well whenever JBOD support was > added and it introduced bug that > SYNCHRONIZE_CACHE is not passed to FW for JBOD (non Raid disk). > > But our recent analysis indicates that, From Day-1 MR Firmware always > expect Driver to forward SYNCHRONIZE_CACHE for JBOD (non Raid disk) > to the > Firmware. > We have fixed this as part of this patch. > > - Additional background - > There are some instance of MegaRaid FW (E.a Gen2 and Gen2.5 FW) set > WCE bit > for Virtual Disk but firmware does not reply correct status for > SYNCH_CACHE. > It is very difficult to find out which Device ID and firmware has > capability > to manage SYNC_CACHE, so we managed to figure out which are the new > firmware > (canHandleSyncCache is set in scratch pad register at 0xB4) and use > that > interface for correct behavior as explained above. > > E.g Liberator/Thunderbolt MegaRaid FW returns SYNC_CACHE as > Unsupported > command (this is a firmware bug) and eventually command will be > failed to SML. > This will cause File system to go Read-only. > > - New behavior described - > > IF application requests SYNCH_CACHE > IF 'JBOD' > Driver sends SYNCH_CACHE command to the FW > FW sends SYNCH_CACHE to drive > FW obtains status from drive and returns same status > back to driver > ELSEIF 'VirtualDisk' > IF any FW which supports new API bit called > canHandleSyncCache > Driver sends SYNCH_CACHE command to the > FW > FW does not send SYNCH_CACHE to drives > FW returns SUCCESS > ELSE > Driver does not send SYNCH_CACHE > command to the FW. > Driver return SUCCESS for that command. > ENDIF > ENDIF > ENDIF > > CC: stable@vger.kernel.org Can you please split this into two, so we can backport the bug fix without any of the feature addition junk? > Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com> > Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> > --- > drivers/scsi/megaraid/megaraid_sas.h | 3 +++ > drivers/scsi/megaraid/megaraid_sas_base.c | 10 ++-------- > drivers/scsi/megaraid/megaraid_sas_fusion.c | 5 +++++ > 3 files changed, 10 insertions(+), 8 deletions(-) > > diff --git a/drivers/scsi/megaraid/megaraid_sas.h > b/drivers/scsi/megaraid/megaraid_sas.h > index ca86c88..43fd14f 100644 > --- a/drivers/scsi/megaraid/megaraid_sas.h > +++ b/drivers/scsi/megaraid/megaraid_sas.h > @@ -1429,6 +1429,8 @@ enum FW_BOOT_CONTEXT { > #define MR_MAX_REPLY_QUEUES_EXT_OFFSET_SHIFT 14 > #define MR_MAX_MSIX_REG_ARRAY 16 > #define MR_RDPQ_MODE_OFFSET 0X00800000 > +#define MR_CAN_HANDLE_SYNC_CACHE_OFFSET 0X01000000 > + > /* > * register set for both 1068 and 1078 controllers > * structure extended for 1078 registers > @@ -2140,6 +2142,7 @@ struct megasas_instance { > u8 is_imr; > u8 is_rdpq; > bool dev_handle; > + bool fw_sync_cache_support; > }; > struct MR_LD_VF_MAP { > u32 size; > diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c > b/drivers/scsi/megaraid/megaraid_sas_base.c > index 3236632..f7a2ab1 100644 > --- a/drivers/scsi/megaraid/megaraid_sas_base.c > +++ b/drivers/scsi/megaraid/megaraid_sas_base.c > @@ -1700,16 +1700,10 @@ inline int megasas_cmd_type(struct scsi_cmnd > *cmd) > goto out_done; > } > > - switch (scmd->cmnd[0]) { > - case SYNCHRONIZE_CACHE: > - /* > - * FW takes care of flush cache on its own > - * No need to send it down > - */ > + if (MEGASAS_IS_LOGICAL(scmd) && (scmd->cmnd[0] == > SYNCHRONIZE_CACHE) && > + (!instance->fw_sync_cache_support)) { > scmd->result = DID_OK << 16; > goto out_done; This, minus the "&& (!instance->fw_sync_cache_support)" is all we need for the bug fix, correct? James > - default: > - break; > } > > return instance->instancet->build_and_issue_cmd(instance, > scmd); > diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c > b/drivers/scsi/megaraid/megaraid_sas_fusion.c > index 2159f6a..2e61306 100644 > --- a/drivers/scsi/megaraid/megaraid_sas_fusion.c > +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c > @@ -748,6 +748,11 @@ static int megasas_create_sg_sense_fusion(struct > megasas_instance *instance) > goto fail_fw_init; > } > > + instance->fw_sync_cache_support = (scratch_pad_2 & > + MR_CAN_HANDLE_SYNC_CACHE_OFFSET) ? 1 : 0; > + dev_info(&instance->pdev->dev, "FW supports sync cache\t: > %s\n", > + instance->fw_sync_cache_support ? "Yes" : "No"); > + > IOCInitMessage = > dma_alloc_coherent(&instance->pdev->dev, > sizeof(struct MPI2_IOC_INIT_REQUEST), -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 21.10.2016 13:01, James Bottomley wrote: > On Thu, 2016-10-20 at 02:05 -0700, Sumit Saxena wrote: >> From previous patch we have below changes in v2 - >> 1. Updated change log. Provided more detail in change log. >> 2. Agreed to remove module parameter. If we remove module parameter, >> we >> can ask customer to disable WCE on drive to get similar impact. >> 3. Always Send SYNCHRONIZE_CACHE for JBOD (non Raid) Device to >> Firmware. >> >> Current megaraid_sas driver returns SYNCHRONIZE_CACHE(related to >> Drive >> Cache) command back to SCSI layer without sending it down to >> firmware as >> firmware supposed to take care of flushing disk cache for all drives >> belongs to Virtual Disk at the time of system reboot/shutdown. >> >> We evaluate and understood that for Raid Volume, why driver should >> not >> send SYNC_CACHE command to the Firmware. >> There may be a some reason in past, but now it looks to be not >> required and >> we have fixed this issue as part of this patch. >> >> Commit- " 02b01e0 [SCSI] megaraid_sas: return sync cache call with >> success" >> added the code in driver to return SYNCHRONIZE_CACHE without sending >> it to >> firmware back in 2007. Earlier MR was mainly for Virtual Disk, >> so same code continue for JBOD as well whenever JBOD support was >> added and it introduced bug that >> SYNCHRONIZE_CACHE is not passed to FW for JBOD (non Raid disk). >> >> But our recent analysis indicates that, From Day-1 MR Firmware always >> expect Driver to forward SYNCHRONIZE_CACHE for JBOD (non Raid disk) >> to the >> Firmware. >> We have fixed this as part of this patch. >> >> - Additional background - >> There are some instance of MegaRaid FW (E.a Gen2 and Gen2.5 FW) set >> WCE bit >> for Virtual Disk but firmware does not reply correct status for >> SYNCH_CACHE. >> It is very difficult to find out which Device ID and firmware has >> capability >> to manage SYNC_CACHE, so we managed to figure out which are the new >> firmware >> (canHandleSyncCache is set in scratch pad register at 0xB4) and use >> that >> interface for correct behavior as explained above. >> >> E.g Liberator/Thunderbolt MegaRaid FW returns SYNC_CACHE as >> Unsupported >> command (this is a firmware bug) and eventually command will be >> failed to SML. >> This will cause File system to go Read-only. >> >> - New behavior described - >> >> IF application requests SYNCH_CACHE >> IF 'JBOD' >> Driver sends SYNCH_CACHE command to the FW >> FW sends SYNCH_CACHE to drive >> FW obtains status from drive and returns same status >> back to driver >> ELSEIF 'VirtualDisk' >> IF any FW which supports new API bit called >> canHandleSyncCache >> Driver sends SYNCH_CACHE command to the >> FW >> FW does not send SYNCH_CACHE to drives >> FW returns SUCCESS >> ELSE >> Driver does not send SYNCH_CACHE >> command to the FW. >> Driver return SUCCESS for that command. >> ENDIF >> ENDIF >> ENDIF >> >> CC: stable@vger.kernel.org > Can you please split this into two, so we can backport the bug fix > without any of the feature addition junk? > >> Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com> >> Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> >> --- >> drivers/scsi/megaraid/megaraid_sas.h | 3 +++ >> drivers/scsi/megaraid/megaraid_sas_base.c | 10 ++-------- >> drivers/scsi/megaraid/megaraid_sas_fusion.c | 5 +++++ >> 3 files changed, 10 insertions(+), 8 deletions(-) >> >> diff --git a/drivers/scsi/megaraid/megaraid_sas.h >> b/drivers/scsi/megaraid/megaraid_sas.h >> index ca86c88..43fd14f 100644 >> --- a/drivers/scsi/megaraid/megaraid_sas.h >> +++ b/drivers/scsi/megaraid/megaraid_sas.h >> @@ -1429,6 +1429,8 @@ enum FW_BOOT_CONTEXT { >> #define MR_MAX_REPLY_QUEUES_EXT_OFFSET_SHIFT 14 >> #define MR_MAX_MSIX_REG_ARRAY 16 >> #define MR_RDPQ_MODE_OFFSET 0X00800000 >> +#define MR_CAN_HANDLE_SYNC_CACHE_OFFSET 0X01000000 >> + >> /* >> * register set for both 1068 and 1078 controllers >> * structure extended for 1078 registers >> @@ -2140,6 +2142,7 @@ struct megasas_instance { >> u8 is_imr; >> u8 is_rdpq; >> bool dev_handle; >> + bool fw_sync_cache_support; >> }; >> struct MR_LD_VF_MAP { >> u32 size; >> diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c >> b/drivers/scsi/megaraid/megaraid_sas_base.c >> index 3236632..f7a2ab1 100644 >> --- a/drivers/scsi/megaraid/megaraid_sas_base.c >> +++ b/drivers/scsi/megaraid/megaraid_sas_base.c >> @@ -1700,16 +1700,10 @@ inline int megasas_cmd_type(struct scsi_cmnd >> *cmd) >> goto out_done; >> } >> >> - switch (scmd->cmnd[0]) { >> - case SYNCHRONIZE_CACHE: >> - /* >> - * FW takes care of flush cache on its own >> - * No need to send it down >> - */ >> + if (MEGASAS_IS_LOGICAL(scmd) && (scmd->cmnd[0] == >> SYNCHRONIZE_CACHE) && >> + (!instance->fw_sync_cache_support)) { >> scmd->result = DID_OK << 16; >> goto out_done; > This, minus the "&& (!instance->fw_sync_cache_support)" is all we need > for the bug fix, correct? Isn't both a) sending SYNC to JBOD and b) sending SYNC to logical luns a bugfix of the same kind? > > James > >> - default: >> - break; >> } >> >> return instance->instancet->build_and_issue_cmd(instance, >> scmd); >> diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c >> b/drivers/scsi/megaraid/megaraid_sas_fusion.c >> index 2159f6a..2e61306 100644 >> --- a/drivers/scsi/megaraid/megaraid_sas_fusion.c >> +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c >> @@ -748,6 +748,11 @@ static int megasas_create_sg_sense_fusion(struct >> megasas_instance *instance) >> goto fail_fw_init; >> } >> >> + instance->fw_sync_cache_support = (scratch_pad_2 & >> + MR_CAN_HANDLE_SYNC_CACHE_OFFSET) ? 1 : 0; >> + dev_info(&instance->pdev->dev, "FW supports sync cache\t: >> %s\n", >> + instance->fw_sync_cache_support ? "Yes" : "No"); >> + >> IOCInitMessage = >> dma_alloc_coherent(&instance->pdev->dev, >> sizeof(struct MPI2_IOC_INIT_REQUEST), > -- > To unsubscribe from this list: send the line "unsubscribe linux-scsi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h index ca86c88..43fd14f 100644 --- a/drivers/scsi/megaraid/megaraid_sas.h +++ b/drivers/scsi/megaraid/megaraid_sas.h @@ -1429,6 +1429,8 @@ enum FW_BOOT_CONTEXT { #define MR_MAX_REPLY_QUEUES_EXT_OFFSET_SHIFT 14 #define MR_MAX_MSIX_REG_ARRAY 16 #define MR_RDPQ_MODE_OFFSET 0X00800000 +#define MR_CAN_HANDLE_SYNC_CACHE_OFFSET 0X01000000 + /* * register set for both 1068 and 1078 controllers * structure extended for 1078 registers @@ -2140,6 +2142,7 @@ struct megasas_instance { u8 is_imr; u8 is_rdpq; bool dev_handle; + bool fw_sync_cache_support; }; struct MR_LD_VF_MAP { u32 size; diff --git a/drivers/scsi/megaraid/megaraid_sas_base.c b/drivers/scsi/megaraid/megaraid_sas_base.c index 3236632..f7a2ab1 100644 --- a/drivers/scsi/megaraid/megaraid_sas_base.c +++ b/drivers/scsi/megaraid/megaraid_sas_base.c @@ -1700,16 +1700,10 @@ inline int megasas_cmd_type(struct scsi_cmnd *cmd) goto out_done; } - switch (scmd->cmnd[0]) { - case SYNCHRONIZE_CACHE: - /* - * FW takes care of flush cache on its own - * No need to send it down - */ + if (MEGASAS_IS_LOGICAL(scmd) && (scmd->cmnd[0] == SYNCHRONIZE_CACHE) && + (!instance->fw_sync_cache_support)) { scmd->result = DID_OK << 16; goto out_done; - default: - break; } return instance->instancet->build_and_issue_cmd(instance, scmd); diff --git a/drivers/scsi/megaraid/megaraid_sas_fusion.c b/drivers/scsi/megaraid/megaraid_sas_fusion.c index 2159f6a..2e61306 100644 --- a/drivers/scsi/megaraid/megaraid_sas_fusion.c +++ b/drivers/scsi/megaraid/megaraid_sas_fusion.c @@ -748,6 +748,11 @@ static int megasas_create_sg_sense_fusion(struct megasas_instance *instance) goto fail_fw_init; } + instance->fw_sync_cache_support = (scratch_pad_2 & + MR_CAN_HANDLE_SYNC_CACHE_OFFSET) ? 1 : 0; + dev_info(&instance->pdev->dev, "FW supports sync cache\t: %s\n", + instance->fw_sync_cache_support ? "Yes" : "No"); + IOCInitMessage = dma_alloc_coherent(&instance->pdev->dev, sizeof(struct MPI2_IOC_INIT_REQUEST),
From previous patch we have below changes in v2 - 1. Updated change log. Provided more detail in change log. 2. Agreed to remove module parameter. If we remove module parameter, we can ask customer to disable WCE on drive to get similar impact. 3. Always Send SYNCHRONIZE_CACHE for JBOD (non Raid) Device to Firmware. Current megaraid_sas driver returns SYNCHRONIZE_CACHE(related to Drive Cache) command back to SCSI layer without sending it down to firmware as firmware supposed to take care of flushing disk cache for all drives belongs to Virtual Disk at the time of system reboot/shutdown. We evaluate and understood that for Raid Volume, why driver should not send SYNC_CACHE command to the Firmware. There may be a some reason in past, but now it looks to be not required and we have fixed this issue as part of this patch. Commit- " 02b01e0 [SCSI] megaraid_sas: return sync cache call with success" added the code in driver to return SYNCHRONIZE_CACHE without sending it to firmware back in 2007. Earlier MR was mainly for Virtual Disk, so same code continue for JBOD as well whenever JBOD support was added and it introduced bug that SYNCHRONIZE_CACHE is not passed to FW for JBOD (non Raid disk). But our recent analysis indicates that, From Day-1 MR Firmware always expect Driver to forward SYNCHRONIZE_CACHE for JBOD (non Raid disk) to the Firmware. We have fixed this as part of this patch. - Additional background - There are some instance of MegaRaid FW (E.a Gen2 and Gen2.5 FW) set WCE bit for Virtual Disk but firmware does not reply correct status for SYNCH_CACHE. It is very difficult to find out which Device ID and firmware has capability to manage SYNC_CACHE, so we managed to figure out which are the new firmware (canHandleSyncCache is set in scratch pad register at 0xB4) and use that interface for correct behavior as explained above. E.g Liberator/Thunderbolt MegaRaid FW returns SYNC_CACHE as Unsupported command (this is a firmware bug) and eventually command will be failed to SML. This will cause File system to go Read-only. - New behavior described - IF application requests SYNCH_CACHE IF 'JBOD' Driver sends SYNCH_CACHE command to the FW FW sends SYNCH_CACHE to drive FW obtains status from drive and returns same status back to driver ELSEIF 'VirtualDisk' IF any FW which supports new API bit called canHandleSyncCache Driver sends SYNCH_CACHE command to the FW FW does not send SYNCH_CACHE to drives FW returns SUCCESS ELSE Driver does not send SYNCH_CACHE command to the FW. Driver return SUCCESS for that command. ENDIF ENDIF ENDIF CC: stable@vger.kernel.org Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com> Signed-off-by: Sumit Saxena <sumit.saxena@broadcom.com> --- drivers/scsi/megaraid/megaraid_sas.h | 3 +++ drivers/scsi/megaraid/megaraid_sas_base.c | 10 ++-------- drivers/scsi/megaraid/megaraid_sas_fusion.c | 5 +++++ 3 files changed, 10 insertions(+), 8 deletions(-)