Re: [PATCH v18 1/2] scsi: ufs: Enable power management for wlun
From: Bart Van Assche <bvanassche@acm.org>
Date: 2021-04-15 23:11:31
Also in:
linux-arm-msm, linux-mediatek, linux-samsung-soc, linux-scsi, lkml
On 4/14/21 11:58 AM, Asutosh Das wrote:
[ ... ]
Patches sent to the SCSI mailing list should not have a "scsi: " prefix in the subject. That prefix is inserted before any SCSI patches go into Martin's tree.
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diff --git a/drivers/scsi/ufs/cdns-pltfrm.c b/drivers/scsi/ufs/cdns-pltfrm.c index 13d9204..b9105e4 100644 --- a/drivers/scsi/ufs/cdns-pltfrm.c +++ b/drivers/scsi/ufs/cdns-pltfrm.c@@ -323,6 +323,8 @@ static const struct dev_pm_ops cdns_ufs_dev_pm_ops = { .runtime_suspend = ufshcd_pltfrm_runtime_suspend, .runtime_resume = ufshcd_pltfrm_runtime_resume, .runtime_idle = ufshcd_pltfrm_runtime_idle, + .prepare = ufshcd_suspend_prepare, + .complete = ufshcd_resume_complete, }; static struct platform_driver cdns_ufs_pltfrm_driver = {diff --git a/drivers/scsi/ufs/tc-dwc-g210-pci.c b/drivers/scsi/ufs/tc-dwc-g210-pci.c index 67a6a61..b01db12 100644 --- a/drivers/scsi/ufs/tc-dwc-g210-pci.c +++ b/drivers/scsi/ufs/tc-dwc-g210-pci.c@@ -148,6 +148,8 @@ static const struct dev_pm_ops tc_dwc_g210_pci_pm_ops = { .runtime_suspend = tc_dwc_g210_pci_runtime_suspend, .runtime_resume = tc_dwc_g210_pci_runtime_resume, .runtime_idle = tc_dwc_g210_pci_runtime_idle, + .prepare = ufshcd_suspend_prepare, + .complete = ufshcd_resume_complete, };
[ ... ]
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--- a/drivers/scsi/ufs/ufs-exynos.c +++ b/drivers/scsi/ufs/ufs-exynos.c@@ -1267,6 +1267,8 @@ static const struct dev_pm_ops exynos_ufs_pm_ops = { .runtime_suspend = ufshcd_pltfrm_runtime_suspend, .runtime_resume = ufshcd_pltfrm_runtime_resume, .runtime_idle = ufshcd_pltfrm_runtime_idle, + .prepare = ufshcd_suspend_prepare, + .complete = ufshcd_resume_complete, }; static struct platform_driver exynos_ufs_pltform = {diff --git a/drivers/scsi/ufs/ufs-hisi.c b/drivers/scsi/ufs/ufs-hisi.c index 0aa5813..d463b44 100644 --- a/drivers/scsi/ufs/ufs-hisi.c +++ b/drivers/scsi/ufs/ufs-hisi.c@@ -574,6 +574,8 @@ static const struct dev_pm_ops ufs_hisi_pm_ops = { .runtime_suspend = ufshcd_pltfrm_runtime_suspend, .runtime_resume = ufshcd_pltfrm_runtime_resume, .runtime_idle = ufshcd_pltfrm_runtime_idle, + .prepare = ufshcd_suspend_prepare, + .complete = ufshcd_resume_complete, };
A minor comment about source code formatting: please make sure that the equality signs are aligned in struct dev_pm_ops definitions.
+static inline bool is_rpmb_wlun(struct scsi_device *sdev)
+{
+ return (sdev->lun == ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_RPMB_WLUN));
+}
+
+static inline bool is_device_wlun(struct scsi_device *sdev)
+{
+ return (sdev->lun ==
+ ufshcd_upiu_wlun_to_scsi_wlun(UFS_UPIU_UFS_DEVICE_WLUN));
+}The Linux kernel coding style requires not to surround expressions with parentheses in return statements.
/**
+ * ufshcd_setup_links - associate link b/w device wlun and other luns
+ * @sdev: pointer to SCSI device
+ * @hba: pointer to ufs hba
+ */
+static void ufshcd_setup_links(struct ufs_hba *hba, struct scsi_device *sdev)
+{
+ struct device_link *link;
+
+ /*
+ * device wlun is the supplier & rest of the luns are consumers
+ * This ensures that device wlun suspends after all other luns.
+ */
+ if (hba->sdev_ufs_device) {
+ link = device_link_add(&sdev->sdev_gendev,
+ &hba->sdev_ufs_device->sdev_gendev,
+ DL_FLAG_PM_RUNTIME|DL_FLAG_RPM_ACTIVE);
+ if (!link) {
+ dev_err(&sdev->sdev_gendev, "Failed establishing link - %s\n",
+ dev_name(&hba->sdev_ufs_device->sdev_gendev));
+ return;
+ }
+ hba->luns_avail--;
+ /* Ignore REPORT_LUN wlun probing */
+ if (hba->luns_avail == 1) {
+ ufshcd_rpm_put(hba);
+ return;
+ }
+ } else {
+ /* device wlun is probed */
+ hba->luns_avail--;
+ }
+}Please add a comment that explains that it is assumed that the WLUNs are scanned before the other LUNs.
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@@ -4862,8 +4913,13 @@ static int ufshcd_slave_configure(struct scsi_device *sdev) blk_queue_update_dma_pad(q, PRDT_DATA_BYTE_COUNT_PAD - 1); if (hba->quirks & UFSHCD_QUIRK_ALIGN_SG_WITH_PAGE_SIZE) blk_queue_update_dma_alignment(q, PAGE_SIZE - 1); - - if (ufshcd_is_rpm_autosuspend_allowed(hba)) + /* + * Block runtime-pm until all consumers are added. + * Refer ufshcd_setup_links(). + */ + if (is_device_wlun(sdev)) + pm_runtime_get_noresume(&sdev->sdev_gendev); + else if (ufshcd_is_rpm_autosuspend_allowed(hba)) sdev->rpm_autosuspend = 1; ufshcd_crypto_setup_rq_keyslot_manager(hba, q);
The following code is executed before ufshcd_async_scan() is called: dev = hba->dev; [ ... ] /* Hold auto suspend until async scan completes */ pm_runtime_get_sync(dev); and the following code occurs in ufshcd_add_lus(): pm_runtime_put_sync(hba->dev); Isn't that sufficient to postpone enabling of runtime PM until LUN scanning has finished? Or in other words, is adding a pm_runtime_get_noresume() call in ufshcd_slave_configure() really necessary?
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@@ -4979,15 +5035,9 @@ ufshcd_transfer_rsp_status(struct ufs_hba *hba, struct ufshcd_lrb *lrbp) */ if (!hba->pm_op_in_progress && !ufshcd_eh_in_progress(hba) && - ufshcd_is_exception_event(lrbp->ucd_rsp_ptr) && - schedule_work(&hba->eeh_work)) { - /* - * Prevent suspend once eeh_work is scheduled - * to avoid deadlock between ufshcd_suspend - * and exception event handler. - */ - pm_runtime_get_noresume(hba->dev); - } + ufshcd_is_exception_event(lrbp->ucd_rsp_ptr)) + /* Flushed in suspend */ + schedule_work(&hba->eeh_work);
What makes it safe to leave out the above pm_runtime_get_noresume() call? Thanks, Bart. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel