Commit bb44826c authored by Adrian Hunter's avatar Adrian Hunter Committed by Martin K. Petersen
Browse files

scsi: ufs: ufs-pci: Fix S0ix/S3 for Intel controllers 



Intel platforms with UFS, can support Suspend-to-Idle (S0ix) and
Suspend-to-RAM (S3).  For S0ix the link state should be HIBERNATE.  For
S3, state is lost, so the link state must be OFF.  Driver policy,
expressed by spm_lvl, can be 3 (link HIBERNATE, device SLEEP) for S0ix
but must be changed to 5 (link OFF, device POWEROFF) for S3.

Fix support for S0ix/S3 by switching spm_lvl as needed.  During suspend
->prepare(), if the suspend target state is not Suspend-to-Idle, ensure
the spm_lvl is at least 5 to ensure that resume will be possible from
deep sleep states.  During suspend ->complete(), restore the spm_lvl to
its original value that is suitable for S0ix.

This fix is first needed in Intel Alder Lake based controllers.

Fixes: 7dc9fb47 ("scsi: ufs: ufs-pci: Add support for Intel ADL")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Reviewed-by: default avatarBart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20251024085918.31825-2-adrian.hunter@intel.com


Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent f838d624

drivers/ufs/host/ufshcd-pci.c

+65 −2
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/pci.h>

#include <linux/pm_runtime.h>

#include <linux/pm_qos.h>

#include <linux/suspend.h>

#include <linux/debugfs.h>

#include <linux/uuid.h>

#include <linux/acpi.h>
@@ -31,6 +32,7 @@ struct intel_host { 
	u32		dsm_fns;

	u32		active_ltr;

	u32		idle_ltr;

	int		saved_spm_lvl;

	struct dentry	*debugfs_root;

	struct gpio_desc *reset_gpio;

};
@@ -347,6 +349,7 @@ static int ufs_intel_common_init(struct ufs_hba *hba) 
	host = devm_kzalloc(hba->dev, sizeof(*host), GFP_KERNEL);

	if (!host)

		return -ENOMEM;

	host->saved_spm_lvl = -1;

	ufshcd_set_variant(hba, host);

	intel_dsm_init(host, hba->dev);

	if (INTEL_DSM_SUPPORTED(host, RESET)) {
@@ -538,6 +541,66 @@ static int ufshcd_pci_restore(struct device *dev) 


	return ufshcd_system_resume(dev);

}



static int ufs_intel_suspend_prepare(struct device *dev)

{

	struct ufs_hba *hba = dev_get_drvdata(dev);

	struct intel_host *host = ufshcd_get_variant(hba);

	int err;



	/*

	 * Only s2idle (S0ix) retains link state.  Force power-off

	 * (UFS_PM_LVL_5) for any other case.

	 */

	if (pm_suspend_target_state != PM_SUSPEND_TO_IDLE && hba->spm_lvl < UFS_PM_LVL_5) {

		host->saved_spm_lvl = hba->spm_lvl;

		hba->spm_lvl = UFS_PM_LVL_5;

	}



	err = ufshcd_suspend_prepare(dev);



	if (err < 0 && host->saved_spm_lvl != -1) {

		hba->spm_lvl = host->saved_spm_lvl;

		host->saved_spm_lvl = -1;

	}



	return err;

}



static void ufs_intel_resume_complete(struct device *dev)

{

	struct ufs_hba *hba = dev_get_drvdata(dev);

	struct intel_host *host = ufshcd_get_variant(hba);



	ufshcd_resume_complete(dev);



	if (host->saved_spm_lvl != -1) {

		hba->spm_lvl = host->saved_spm_lvl;

		host->saved_spm_lvl = -1;

	}

}



static int ufshcd_pci_suspend_prepare(struct device *dev)

{

	struct ufs_hba *hba = dev_get_drvdata(dev);



	if (!strcmp(hba->vops->name, "intel-pci"))

		return ufs_intel_suspend_prepare(dev);



	return ufshcd_suspend_prepare(dev);

}



static void ufshcd_pci_resume_complete(struct device *dev)

{

	struct ufs_hba *hba = dev_get_drvdata(dev);



	if (!strcmp(hba->vops->name, "intel-pci")) {

		ufs_intel_resume_complete(dev);

		return;

	}



	ufshcd_resume_complete(dev);

}

#endif



/**
@@ -611,8 +674,8 @@ static const struct dev_pm_ops ufshcd_pci_pm_ops = { 
	.thaw		= ufshcd_system_resume,

	.poweroff	= ufshcd_system_suspend,

	.restore	= ufshcd_pci_restore,

	.prepare	= ufshcd_suspend_prepare,

	.complete	= ufshcd_resume_complete,

	.prepare	= ufshcd_pci_suspend_prepare,

	.complete	= ufshcd_pci_resume_complete,

#endif

};