Messages in this thread | | | Date | Wed, 23 Jul 2014 10:10:38 +0800 | From | Mike Qiu <> | Subject | Re: [PATCH 1/2] libata: Fix scsi_host can_queue issue in ata_qc_new() |
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On 07/22/2014 11:42 PM, Tejun Heo wrote: > Hello, > > (cc'ing Dan) > > On Tue, Jul 22, 2014 at 10:50:19AM -0400, Mike Qiu wrote: >> The can_queue in scsi_host can be more than ATA_MAX_QUEUE (32), >> for example, in ipr, it can be 100 or more. >> >> Also, some drivers, like ipr driver, haven't filled the field >> scsi_host in ata_port, and will lead a call trace, so add >> check for that. >> >> Signed-off-by: Mike Qiu <qiudayu@linux.vnet.ibm.com> >> --- >> drivers/ata/libata-core.c | 15 ++++----------- >> 1 file changed, 4 insertions(+), 11 deletions(-) >> >> diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c >> index 259d879..a5b9c70 100644 >> --- a/drivers/ata/libata-core.c >> +++ b/drivers/ata/libata-core.c >> @@ -4734,7 +4734,10 @@ static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap) >> struct ata_queued_cmd *qc = NULL; >> unsigned int i, tag, max_queue; >> >> - max_queue = ap->scsi_host->can_queue; >> + if (ap->scsi_host && ap->scsi_host->can_queue <= ATA_MAX_QUEUE) >> + max_queue = ap->scsi_host->can_queue; >> + else >> + max_queue = ATA_MAX_QUEUE; >> >> /* no command while frozen */ >> if (unlikely(ap->pflags & ATA_PFLAG_FROZEN)) >> @@ -6109,16 +6112,6 @@ int ata_host_register(struct ata_host *host, struct scsi_host_template *sht) >> { >> int i, rc; >> >> - /* >> - * The max queue supported by hardware must not be greater than >> - * ATA_MAX_QUEUE. >> - */ >> - if (sht->can_queue > ATA_MAX_QUEUE) { >> - dev_err(host->dev, "BUG: the hardware max queue is too large\n"); >> - WARN_ON(1); >> - return -EINVAL; >> - } >> - > So, ummm, I really don't like that we're adding the conditionals to > the hot path (yeah, its implementation is slow but still). Maybe we
Yes, agree ..., not a good idea to do this...
Thanks Mike > need to store the chosen queue depth after all? Dan? > > Thanks. >
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