This is a note to let you know that I've just added the patch titled

scsi: ufs: add capability to keep auto bkops always enabled

to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: scsi-ufs-add-capability-to-keep-auto-bkops-always-enabled.patch and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From foo@baz Sun Nov 19 12:02:55 CET 2017

From: "subhashj@codeaurora.org" subhashj@codeaurora.org Date: Thu, 22 Dec 2016 18:41:22 -0800 Subject: scsi: ufs: add capability to keep auto bkops always enabled

From: "subhashj@codeaurora.org" subhashj@codeaurora.org

[ Upstream commit 4e768e7645ec4ffa92ee163643777b261ae97142 ]

UFS device requires to perform bkops (back ground operations) periodically but host can control (via auto-bkops parameter of device) when device can perform bkops based on its performance requirements. In general, host would like to enable the device's auto-bkops only when it's not doing any regular data transfer but sometimes device may not behave properly if host keeps the auto-bkops disabled. This change adds the capability to let the device auto-bkops always enabled except suspend.

Reviewed-by: Sahitya Tummala stummala@codeaurora.org Signed-off-by: Subhash Jadavani subhashj@codeaurora.org Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Sasha Levin alexander.levin@verizon.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/scsi/ufs/ufshcd.c | 33 ++++++++++++++++++++++----------- drivers/scsi/ufs/ufshcd.h | 13 +++++++++++++ 2 files changed, 35 insertions(+), 11 deletions(-)

--- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -3340,18 +3340,25 @@ out: }

/** - * ufshcd_force_reset_auto_bkops - force enable of auto bkops + * ufshcd_force_reset_auto_bkops - force reset auto bkops state * @hba: per adapter instance * * After a device reset the device may toggle the BKOPS_EN flag * to default value. The s/w tracking variables should be updated - * as well. Do this by forcing enable of auto bkops. + * as well. This function would change the auto-bkops state based on + * UFSHCD_CAP_KEEP_AUTO_BKOPS_ENABLED_EXCEPT_SUSPEND. */ -static void ufshcd_force_reset_auto_bkops(struct ufs_hba *hba) +static void ufshcd_force_reset_auto_bkops(struct ufs_hba *hba) { - hba->auto_bkops_enabled = false; - hba->ee_ctrl_mask |= MASK_EE_URGENT_BKOPS; - ufshcd_enable_auto_bkops(hba); + if (ufshcd_keep_autobkops_enabled_except_suspend(hba)) { + hba->auto_bkops_enabled = false; + hba->ee_ctrl_mask |= MASK_EE_URGENT_BKOPS; + ufshcd_enable_auto_bkops(hba); + } else { + hba->auto_bkops_enabled = true; + hba->ee_ctrl_mask &= ~MASK_EE_URGENT_BKOPS; + ufshcd_disable_auto_bkops(hba); + } }

static inline int ufshcd_get_bkops_status(struct ufs_hba *hba, u32 *status) @@ -5149,11 +5156,15 @@ static int ufshcd_resume(struct ufs_hba goto set_old_link_state; }

- /* - * If BKOPs operations are urgently needed at this moment then - * keep auto-bkops enabled or else disable it. - */ - ufshcd_urgent_bkops(hba); + if (ufshcd_keep_autobkops_enabled_except_suspend(hba)) + ufshcd_enable_auto_bkops(hba); + else + /* + * If BKOPs operations are urgently needed at this moment then + * keep auto-bkops enabled or else disable it. + */ + ufshcd_urgent_bkops(hba); + hba->clk_gating.is_suspended = false;

if (ufshcd_is_clkscaling_enabled(hba)) --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -528,6 +528,14 @@ struct ufs_hba { * CAUTION: Enabling this might reduce overall UFS throughput. */ #define UFSHCD_CAP_INTR_AGGR (1 << 4) + /* + * This capability allows the device auto-bkops to be always enabled + * except during suspend (both runtime and suspend). + * Enabling this capability means that device will always be allowed + * to do background operation when it's active but it might degrade + * the performance of ongoing read/write operations. + */ +#define UFSHCD_CAP_KEEP_AUTO_BKOPS_ENABLED_EXCEPT_SUSPEND (1 << 5)

struct devfreq *devfreq; struct ufs_clk_scaling clk_scaling; @@ -623,6 +631,11 @@ static inline void *ufshcd_get_variant(s BUG_ON(!hba); return hba->priv; } +static inline bool ufshcd_keep_autobkops_enabled_except_suspend( + struct ufs_hba *hba) +{ + return hba->caps & UFSHCD_CAP_KEEP_AUTO_BKOPS_ENABLED_EXCEPT_SUSPEND; +}

extern int ufshcd_runtime_suspend(struct ufs_hba *hba); extern int ufshcd_runtime_resume(struct ufs_hba *hba);

Patches currently in stable-queue which might be from subhashj@codeaurora.org are

queue-4.4/scsi-ufs-add-capability-to-keep-auto-bkops-always-enabled.patch queue-4.4/scsi-ufs-qcom-fix-module-autoload.patch