On 6/21/2024 4:57 AM, Bart Van Assche wrote:
On 6/7/24 3:06 AM, Ziqi Chen wrote:
Fix this race condition by quiescing the request queues before calling
ufshcd_pending_cmds() so that block layer won't touch the budget map
when ufshcd_pending_cmds() is working on it. In addition, remove the
scsi layer blocking/unblocking to reduce redundancies and latencies.
Can you please help with testing whether the patch below would be a good
alternative to your patch (compile-tested only)?
Thanks,
Bart.
Hi Bart,
Compile-tested is OK, but I don't think it is a better alternative way.
1. Why do we need to call blk_mq_quiesce_tagset() into
ufshcd_scsi_block_requests() instead directly replace all
ufshcd_scsi_block_requests() with blk_mq_quiesce_tagset()?
2. This patch need to to do long-term stress test, I think many OEMs
can't wait as it is a blocker issue for them.
BRs
Ziqi
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index aa00978c6c0e..1d981283b03c 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -332,14 +332,12 @@ static void ufshcd_configure_wb(struct ufs_hba *hba)
static void ufshcd_scsi_unblock_requests(struct ufs_hba *hba)
{
- if (atomic_dec_and_test(&hba->scsi_block_reqs_cnt))
- scsi_unblock_requests(hba->host);
+ blk_mq_quiesce_tagset(&hba->host->tag_set);
}
static void ufshcd_scsi_block_requests(struct ufs_hba *hba)
{
- if (atomic_inc_return(&hba->scsi_block_reqs_cnt) == 1)
- scsi_block_requests(hba->host);
+ blk_mq_unquiesce_tagset(&hba->host->tag_set);
}
static void ufshcd_add_cmd_upiu_trace(struct ufs_hba *hba, unsigned
int tag,
@@ -10590,7 +10588,7 @@ int ufshcd_init(struct ufs_hba *hba, void
__iomem *mmio_base, unsigned int irq)
/* Hold auto suspend until async scan completes */
pm_runtime_get_sync(dev);
- atomic_set(&hba->scsi_block_reqs_cnt, 0);
+
/*
* We are assuming that device wasn't put in sleep/power-down
* state exclusively during the boot stage before kernel.
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index 443afb97a637..58705994fc46 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -889,7 +889,6 @@ enum ufshcd_mcq_opr {
* @wb_mutex: used to serialize devfreq and sysfs write booster toggling
* @clk_scaling_lock: used to serialize device commands and clock scaling
* @desc_size: descriptor sizes reported by device
- * @scsi_block_reqs_cnt: reference counting for scsi block requests
* @bsg_dev: struct device associated with the BSG queue
* @bsg_queue: BSG queue associated with the UFS controller
* @rpm_dev_flush_recheck_work: used to suspend from RPM (runtime power
@@ -1050,7 +1049,6 @@ struct ufs_hba {
struct mutex wb_mutex;
struct rw_semaphore clk_scaling_lock;
- atomic_t scsi_block_reqs_cnt;
struct device bsg_dev;
struct request_queue *bsg_queue;
