Re: [PATCH 3/4] scsi: hisi_sas: Make sg_tablesize consistent value

[Steffen Maier <maier@xxxxxxxxxxxxx>]

On 11/21/2018 12:02 PM, Steffen Maier wrote:
> On 11/20/2018 03:59 PM, John Garry wrote:
> > From: Xiang Chen <chenxiang66@xxxxxxxxxxxxx>
> >
> > Sht->sg_tablesize is set in the driver, and it will be assigned to
> > shost->sg_tablesize in SCSI mid-layer. So it is not necessary to
> > assign shost->sg_table one more time in the driver.
> >
> > In addition to the change, change each scsi_host_template.sg_tablesize
> > to HISI_SAS_SGE_PAGE_CNT instead of SG_ALL.
>
> Might be completely irrelevant, so just as information: I once had 
> problems due to changing (reducing) SHT.sg_tablesize because block queue 
> limits of BSG devices of Scsi_Host and fc_host (not sure if you have an 
> equivalent bsg device for your transport(s)) inherit from SHT, but don't 
> update (automatically) on later updates of shost->sg_tablesize, which in 
> turn affect scsi_devices allocated after the shost update.
> Cf. 
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/drivers/s390/scsi?id=5fea4291deacd80188b996d2f555fc6a1940e5d4 

Figured, your new constant seems to have the same value so no problem.

#define SG_CHUNK_SIZE	128
#define SG_ALL	SG_CHUNK_SIZE
#define HISI_SAS_SGE_PAGE_CNT SG_CHUNK_SIZE

> ("[SCSI] zfcp: block queue limits with data router")
> if you need more details.
>
> > Signed-off-by: Xiang Chen <chenxiang66@xxxxxxxxxxxxx>
> > Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
> > ---
> >   drivers/scsi/hisi_sas/hisi_sas_main.c  | 1 -
> >   drivers/scsi/hisi_sas/hisi_sas_v1_hw.c | 2 +-
> >   drivers/scsi/hisi_sas/hisi_sas_v2_hw.c | 2 +-
> >   drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 3 +--
> >   4 files changed, 3 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c 
> > b/drivers/scsi/hisi_sas/hisi_sas_main.c
> > index d13a662..cbda48e 100644
> > --- a/drivers/scsi/hisi_sas/hisi_sas_main.c
> > +++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
> > @@ -2410,7 +2410,6 @@ int hisi_sas_probe(struct platform_device *pdev,
> >       shost->max_lun = ~0;
> >       shost->max_channel = 1;
> >       shost->max_cmd_len = 16;
> > -    shost->sg_tablesize = min_t(u16, SG_ALL, HISI_SAS_SGE_PAGE_CNT);
> >       if (hisi_hba->hw->slot_index_alloc) {
> >           shost->can_queue = hisi_hba->hw->max_command_entries;
> >           shost->cmd_per_lun = hisi_hba->hw->max_command_entries;
> > diff --git a/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c 
> > b/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
> > index d24342b..2d035cc 100644
> > --- a/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
> > +++ b/drivers/scsi/hisi_sas/hisi_sas_v1_hw.c
> > @@ -1815,7 +1815,7 @@ static int hisi_sas_v1_init(struct hisi_hba 
> > *hisi_hba)
> >       .change_queue_depth    = sas_change_queue_depth,
> >       .bios_param        = sas_bios_param,
> >       .this_id        = -1,
> > -    .sg_tablesize        = SG_ALL,
> > +    .sg_tablesize        = HISI_SAS_SGE_PAGE_CNT,
> >       .max_sectors        = SCSI_DEFAULT_MAX_SECTORS,
> >       .use_clustering        = ENABLE_CLUSTERING,
> >       .eh_device_reset_handler = sas_eh_device_reset_handler,
> > diff --git a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c 
> > b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
> > index e78a97e..79e58a7 100644
> > --- a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
> > +++ b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c
> > @@ -3570,7 +3570,7 @@ struct device_attribute *host_attrs_v2_hw[] = {
> >       .change_queue_depth    = sas_change_queue_depth,
> >       .bios_param        = sas_bios_param,
> >       .this_id        = -1,
> > -    .sg_tablesize        = SG_ALL,
> > +    .sg_tablesize        = HISI_SAS_SGE_PAGE_CNT,
> >       .max_sectors        = SCSI_DEFAULT_MAX_SECTORS,
> >       .use_clustering        = ENABLE_CLUSTERING,
> >       .eh_device_reset_handler = sas_eh_device_reset_handler,
> > diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c 
> > b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
> > index 7e2b020..8a08078 100644
> > --- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
> > +++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
> > @@ -2224,7 +2224,7 @@ struct device_attribute *host_attrs_v3_hw[] = {
> >       .change_queue_depth    = sas_change_queue_depth,
> >       .bios_param        = sas_bios_param,
> >       .this_id        = -1,
> > -    .sg_tablesize        = SG_ALL,
> > +    .sg_tablesize        = HISI_SAS_SGE_PAGE_CNT,
> >       .max_sectors        = SCSI_DEFAULT_MAX_SECTORS,
> >       .use_clustering        = ENABLE_CLUSTERING,
> >       .eh_device_reset_handler = sas_eh_device_reset_handler,
> > @@ -2366,7 +2366,6 @@ struct device_attribute *host_attrs_v3_hw[] = {
> >       shost->max_lun = ~0;
> >       shost->max_channel = 1;
> >       shost->max_cmd_len = 16;
> > -    shost->sg_tablesize = min_t(u16, SG_ALL, HISI_SAS_SGE_PAGE_CNT);
> >       shost->can_queue = hisi_hba->hw->max_command_entries -
> >           HISI_SAS_RESERVED_IPTT_CNT;
> >       shost->cmd_per_lun = hisi_hba->hw->max_command_entries -


--
Mit freundlichen Gruessen / Kind regards
Steffen Maier

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