On 26/05/23 20:29, Bart Van Assche wrote:
> Ungating the clock asynchronously causes ufshcd_queuecommand() to return
> SCSI_MLQUEUE_HOST_BUSY and hence causes commands to be requeued. This is
> suboptimal. Allow ufshcd_queuecommand() to sleep such that clock ungating
> does not trigger command requeuing. Remove the ufshcd_scsi_block_requests()
> and ufshcd_scsi_unblock_requests() calls because these are no longer
> needed. The flush_work(&hba->clk_gating.ungate_work) call is sufficient to
> make the SCSI core wait for clock ungating to complete.
>
> Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
One minor comment below, and we don't use clock gating but it looks
OK to me, so neverthless:
Acked-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
> ---
> drivers/ufs/core/ufs-sysfs.c | 2 +-
> drivers/ufs/core/ufshcd-crypto.c | 2 +-
> drivers/ufs/core/ufshcd-priv.h | 2 +-
> drivers/ufs/core/ufshcd.c | 84 ++++++++++----------------------
> include/ufs/ufshcd.h | 2 +-
> 5 files changed, 30 insertions(+), 62 deletions(-)
>
> diff --git a/drivers/ufs/core/ufs-sysfs.c b/drivers/ufs/core/ufs-sysfs.c
> index 883f0e44b54e..cdf3d5f2b77b 100644
> --- a/drivers/ufs/core/ufs-sysfs.c
> +++ b/drivers/ufs/core/ufs-sysfs.c
> @@ -168,7 +168,7 @@ static ssize_t auto_hibern8_show(struct device *dev,
> }
>
> pm_runtime_get_sync(hba->dev);
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
> ahit = ufshcd_readl(hba, REG_AUTO_HIBERNATE_IDLE_TIMER);
> ufshcd_release(hba);
> pm_runtime_put_sync(hba->dev);
> diff --git a/drivers/ufs/core/ufshcd-crypto.c b/drivers/ufs/core/ufshcd-crypto.c
> index 198360fe5e8e..f2c4422cab86 100644
> --- a/drivers/ufs/core/ufshcd-crypto.c
> +++ b/drivers/ufs/core/ufshcd-crypto.c
> @@ -24,7 +24,7 @@ static int ufshcd_program_key(struct ufs_hba *hba,
> u32 slot_offset = hba->crypto_cfg_register + slot * sizeof(*cfg);
> int err = 0;
>
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
>
> if (hba->vops && hba->vops->program_key) {
> err = hba->vops->program_key(hba, cfg, slot);
> diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
> index d53b93c21a0c..22cac71090ae 100644
> --- a/drivers/ufs/core/ufshcd-priv.h
> +++ b/drivers/ufs/core/ufshcd-priv.h
> @@ -84,7 +84,7 @@ unsigned long ufshcd_mcq_poll_cqe_lock(struct ufs_hba *hba,
> int ufshcd_read_string_desc(struct ufs_hba *hba, u8 desc_index,
> u8 **buf, bool ascii);
>
> -int ufshcd_hold(struct ufs_hba *hba, bool async);
> +void ufshcd_hold(struct ufs_hba *hba);
> void ufshcd_release(struct ufs_hba *hba);
Declarations of ufshcd_hold() / ufshcd_release() seem to be
unnecessarily duplicated in drivers/ufs/core/ufshcd-priv.h
and include/ufs/ufshcd.h
>
> int ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd);
> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
> index c2d9109102f3..2af4289a3bf5 100644
> --- a/drivers/ufs/core/ufshcd.c
> +++ b/drivers/ufs/core/ufshcd.c
> @@ -1189,7 +1189,7 @@ static int ufshcd_wait_for_doorbell_clr(struct ufs_hba *hba,
> bool timeout = false, do_last_check = false;
> ktime_t start;
>
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
> spin_lock_irqsave(hba->host->host_lock, flags);
> /*
> * Wait for all the outstanding tasks/transfer requests.
> @@ -1310,7 +1310,7 @@ static int ufshcd_clock_scaling_prepare(struct ufs_hba *hba, u64 timeout_us)
> }
>
> /* let's not get into low power until clock scaling is completed */
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
>
> out:
> return ret;
> @@ -1640,7 +1640,7 @@ static ssize_t ufshcd_clkscale_enable_store(struct device *dev,
> goto out;
>
> ufshcd_rpm_get_sync(hba);
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
>
> hba->clk_scaling.is_enabled = value;
>
> @@ -1723,7 +1723,7 @@ static void ufshcd_ungate_work(struct work_struct *work)
> spin_lock_irqsave(hba->host->host_lock, flags);
> if (hba->clk_gating.state == CLKS_ON) {
> spin_unlock_irqrestore(hba->host->host_lock, flags);
> - goto unblock_reqs;
> + return;
> }
>
> spin_unlock_irqrestore(hba->host->host_lock, flags);
> @@ -1746,25 +1746,21 @@ static void ufshcd_ungate_work(struct work_struct *work)
> }
> hba->clk_gating.is_suspended = false;
> }
> -unblock_reqs:
> - ufshcd_scsi_unblock_requests(hba);
> }
>
> /**
> * ufshcd_hold - Enable clocks that were gated earlier due to ufshcd_release.
> * Also, exit from hibern8 mode and set the link as active.
> * @hba: per adapter instance
> - * @async: This indicates whether caller should ungate clocks asynchronously.
> */
> -int ufshcd_hold(struct ufs_hba *hba, bool async)
> +void ufshcd_hold(struct ufs_hba *hba)
> {
> - int rc = 0;
> bool flush_result;
> unsigned long flags;
>
> if (!ufshcd_is_clkgating_allowed(hba) ||
> !hba->clk_gating.is_initialized)
> - goto out;
> + return;
> spin_lock_irqsave(hba->host->host_lock, flags);
> hba->clk_gating.active_reqs++;
>
> @@ -1781,15 +1777,10 @@ int ufshcd_hold(struct ufs_hba *hba, bool async)
> */
> if (ufshcd_can_hibern8_during_gating(hba) &&
> ufshcd_is_link_hibern8(hba)) {
> - if (async) {
> - rc = -EAGAIN;
> - hba->clk_gating.active_reqs--;
> - break;
> - }
> spin_unlock_irqrestore(hba->host->host_lock, flags);
> flush_result = flush_work(&hba->clk_gating.ungate_work);
> if (hba->clk_gating.is_suspended && !flush_result)
> - goto out;
> + return;
> spin_lock_irqsave(hba->host->host_lock, flags);
> goto start;
> }
> @@ -1811,21 +1802,14 @@ int ufshcd_hold(struct ufs_hba *hba, bool async)
> hba->clk_gating.state = REQ_CLKS_ON;
> trace_ufshcd_clk_gating(dev_name(hba->dev),
> hba->clk_gating.state);
> - if (queue_work(hba->clk_gating.clk_gating_workq,
> - &hba->clk_gating.ungate_work))
> - ufshcd_scsi_block_requests(hba);
> + queue_work(hba->clk_gating.clk_gating_workq,
> + &hba->clk_gating.ungate_work);
> /*
> * fall through to check if we should wait for this
> * work to be done or not.
> */
> fallthrough;
> case REQ_CLKS_ON:
> - if (async) {
> - rc = -EAGAIN;
> - hba->clk_gating.active_reqs--;
> - break;
> - }
> -
> spin_unlock_irqrestore(hba->host->host_lock, flags);
> flush_work(&hba->clk_gating.ungate_work);
> /* Make sure state is CLKS_ON before returning */
> @@ -1837,8 +1821,6 @@ int ufshcd_hold(struct ufs_hba *hba, bool async)
> break;
> }
> spin_unlock_irqrestore(hba->host->host_lock, flags);
> -out:
> - return rc;
> }
> EXPORT_SYMBOL_GPL(ufshcd_hold);
>
> @@ -2070,7 +2052,7 @@ static void ufshcd_exit_clk_gating(struct ufs_hba *hba)
> ufshcd_remove_clk_gating_sysfs(hba);
>
> /* Ungate the clock if necessary. */
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
> hba->clk_gating.is_initialized = false;
> ufshcd_release(hba);
>
> @@ -2468,7 +2450,7 @@ int ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
> if (hba->quirks & UFSHCD_QUIRK_BROKEN_UIC_CMD)
> return 0;
>
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
> mutex_lock(&hba->uic_cmd_mutex);
> ufshcd_add_delay_before_dme_cmd(hba);
>
> @@ -2871,12 +2853,6 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
>
> WARN_ONCE(tag < 0 || tag >= hba->nutrs, "Invalid tag %d\n", tag);
>
> - /*
> - * Allows the UFS error handler to wait for prior ufshcd_queuecommand()
> - * calls.
> - */
> - rcu_read_lock();
> -
> switch (hba->ufshcd_state) {
> case UFSHCD_STATE_OPERATIONAL:
> break;
> @@ -2922,13 +2898,7 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
>
> hba->req_abort_count = 0;
>
> - err = ufshcd_hold(hba, true);
> - if (err) {
> - err = SCSI_MLQUEUE_HOST_BUSY;
> - goto out;
> - }
> - WARN_ON(ufshcd_is_clkgating_allowed(hba) &&
> - (hba->clk_gating.state != CLKS_ON));
> + ufshcd_hold(hba);
>
> lrbp = &hba->lrb[tag];
> lrbp->cmd = cmd;
> @@ -2956,8 +2926,6 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
> ufshcd_send_command(hba, tag, hwq);
>
> out:
> - rcu_read_unlock();
> -
> if (ufs_trigger_eh()) {
> unsigned long flags;
>
> @@ -3251,7 +3219,7 @@ int ufshcd_query_flag(struct ufs_hba *hba, enum query_opcode opcode,
>
> BUG_ON(!hba);
>
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
> mutex_lock(&hba->dev_cmd.lock);
> ufshcd_init_query(hba, &request, &response, opcode, idn, index,
> selector);
> @@ -3325,7 +3293,7 @@ int ufshcd_query_attr(struct ufs_hba *hba, enum query_opcode opcode,
> return -EINVAL;
> }
>
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
>
> mutex_lock(&hba->dev_cmd.lock);
> ufshcd_init_query(hba, &request, &response, opcode, idn, index,
> @@ -3421,7 +3389,7 @@ static int __ufshcd_query_descriptor(struct ufs_hba *hba,
> return -EINVAL;
> }
>
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
>
> mutex_lock(&hba->dev_cmd.lock);
> ufshcd_init_query(hba, &request, &response, opcode, idn, index,
> @@ -4239,7 +4207,7 @@ int ufshcd_uic_change_pwr_mode(struct ufs_hba *hba, u8 mode)
> uic_cmd.command = UIC_CMD_DME_SET;
> uic_cmd.argument1 = UIC_ARG_MIB(PA_PWRMODE);
> uic_cmd.argument3 = mode;
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
> ret = ufshcd_uic_pwr_ctrl(hba, &uic_cmd);
> ufshcd_release(hba);
>
> @@ -4346,7 +4314,7 @@ void ufshcd_auto_hibern8_update(struct ufs_hba *hba, u32 ahit)
> if (update &&
> !pm_runtime_suspended(&hba->ufs_device_wlun->sdev_gendev)) {
> ufshcd_rpm_get_sync(hba);
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
> ufshcd_auto_hibern8_enable(hba);
> ufshcd_release(hba);
> ufshcd_rpm_put_sync(hba);
> @@ -4939,7 +4907,7 @@ static int ufshcd_verify_dev_init(struct ufs_hba *hba)
> int err = 0;
> int retries;
>
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
> mutex_lock(&hba->dev_cmd.lock);
> for (retries = NOP_OUT_RETRIES; retries > 0; retries--) {
> err = ufshcd_exec_dev_cmd(hba, DEV_CMD_TYPE_NOP,
> @@ -6224,14 +6192,14 @@ static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
> ufshcd_setup_vreg(hba, true);
> ufshcd_config_vreg_hpm(hba, hba->vreg_info.vccq);
> ufshcd_config_vreg_hpm(hba, hba->vreg_info.vccq2);
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
> if (!ufshcd_is_clkgating_allowed(hba))
> ufshcd_setup_clocks(hba, true);
> ufshcd_release(hba);
> pm_op = hba->is_sys_suspended ? UFS_SYSTEM_PM : UFS_RUNTIME_PM;
> ufshcd_vops_resume(hba, pm_op);
> } else {
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
> if (ufshcd_is_clkscaling_supported(hba) &&
> hba->clk_scaling.is_enabled)
> ufshcd_suspend_clkscaling(hba);
> @@ -6239,7 +6207,7 @@ static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
> }
> ufshcd_scsi_block_requests(hba);
> /* Drain ufshcd_queuecommand() */
> - synchronize_rcu();
> + blk_mq_wait_quiesce_done(&hba->host->tag_set);
> cancel_work_sync(&hba->eeh_work);
> }
>
> @@ -6884,7 +6852,7 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba,
> return PTR_ERR(req);
>
> req->end_io_data = &wait;
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
>
> spin_lock_irqsave(host->host_lock, flags);
>
> @@ -7120,7 +7088,7 @@ int ufshcd_exec_raw_upiu_cmd(struct ufs_hba *hba,
> cmd_type = DEV_CMD_TYPE_NOP;
> fallthrough;
> case UPIU_TRANSACTION_QUERY_REQ:
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
> mutex_lock(&hba->dev_cmd.lock);
> err = ufshcd_issue_devman_upiu_cmd(hba, req_upiu, rsp_upiu,
> desc_buff, buff_len,
> @@ -7186,7 +7154,7 @@ int ufshcd_advanced_rpmb_req_handler(struct ufs_hba *hba, struct utp_upiu_req *r
> u16 ehs_len;
>
> /* Protects use of hba->reserved_slot. */
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
> mutex_lock(&hba->dev_cmd.lock);
> down_read(&hba->clk_scaling_lock);
>
> @@ -7420,7 +7388,7 @@ static int ufshcd_abort(struct scsi_cmnd *cmd)
>
> WARN_ONCE(tag < 0, "Invalid tag %d\n", tag);
>
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
> reg = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
> /* If command is already aborted/completed, return FAILED. */
> if (!(test_bit(tag, &hba->outstanding_reqs))) {
> @@ -9412,7 +9380,7 @@ static int __ufshcd_wl_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op)
> * If we can't transition into any of the low power modes
> * just gate the clocks.
> */
> - ufshcd_hold(hba, false);
> + ufshcd_hold(hba);
> hba->clk_gating.is_suspended = true;
>
> if (ufshcd_is_clkscaling_supported(hba))
> diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
> index db2e669985d5..40c537a3880b 100644
> --- a/include/ufs/ufshcd.h
> +++ b/include/ufs/ufshcd.h
> @@ -1357,7 +1357,7 @@ void ufshcd_fixup_dev_quirks(struct ufs_hba *hba,
> int ufshcd_read_string_desc(struct ufs_hba *hba, u8 desc_index,
> u8 **buf, bool ascii);
>
> -int ufshcd_hold(struct ufs_hba *hba, bool async);
> +void ufshcd_hold(struct ufs_hba *hba);
> void ufshcd_release(struct ufs_hba *hba);
>
> void ufshcd_clkgate_delay_set(struct device *dev, unsigned long value);
