| Message ID | 20200512104750.8711-5-stanley.chu@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | scsi: ufs: Fix WriteBooster and cleanup UFS driver | expand |
Hi Stanley, On 5/12/2020 3:47 AM, Stanley Chu wrote: > Currently UFS host driver promises VCC supply if UFS device > needs to do WriteBooster flush during runtime suspend. > > However the UFS specification mentions, > > "While the flushing operation is in progress, the device is > in Active power mode." > > Therefore UFS host driver needs to promise more: Keep UFS > device as "Active power mode", otherwise UFS device shall not > do any flush if device enters Sleep or PowerDown power mode. > > Fix this by not changing device power mode if WriteBooster > flush is required in ufshcd_suspend(). > > Signed-off-by: Stanley Chu <stanley.chu@mediatek.com> > --- > drivers/scsi/ufs/ufs.h | 1 - > drivers/scsi/ufs/ufshcd.c | 39 +++++++++++++++++++-------------------- > 2 files changed, 19 insertions(+), 21 deletions(-) > > diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h > index b3135344ab3f..9e4bc2e97ada 100644 > --- a/drivers/scsi/ufs/ufs.h > +++ b/drivers/scsi/ufs/ufs.h > @@ -577,7 +577,6 @@ struct ufs_dev_info { > u32 d_ext_ufs_feature_sup; > u8 b_wb_buffer_type; > u32 d_wb_alloc_units; > - bool keep_vcc_on; > u8 b_presrv_uspc_en; > }; > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > index 169a3379e468..2d0aff8ac260 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -8101,8 +8101,7 @@ static void ufshcd_vreg_set_lpm(struct ufs_hba *hba) > !hba->dev_info.is_lu_power_on_wp) { > ufshcd_setup_vreg(hba, false); > } else if (!ufshcd_is_ufs_dev_active(hba)) { > - if (!hba->dev_info.keep_vcc_on) > - ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); > + ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); > if (!ufshcd_is_link_active(hba)) { > ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq); > ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq2); > @@ -8172,6 +8171,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) > enum ufs_pm_level pm_lvl; > enum ufs_dev_pwr_mode req_dev_pwr_mode; > enum uic_link_state req_link_state; > + bool keep_curr_dev_pwr_mode = false; > > hba->pm_op_in_progress = 1; > if (!ufshcd_is_shutdown_pm(pm_op)) { > @@ -8226,28 +8226,27 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) > /* make sure that auto bkops is disabled */ > ufshcd_disable_auto_bkops(hba); > } > + > /* > - * With wb enabled, if the bkops is enabled or if the > - * configured WB type is 70% full, keep vcc ON > - * for the device to flush the wb buffer > + * If device needs to do BKOP or WB buffer flush, keep device > + * power mode as "active power mode" and its VCC supply. > */ > - if ((hba->auto_bkops_enabled && ufshcd_is_wb_allowed(hba)) || > - ufshcd_wb_keep_vcc_on(hba)) > - hba->dev_info.keep_vcc_on = true; > - else > - hba->dev_info.keep_vcc_on = false; > - } else { > - hba->dev_info.keep_vcc_on = false; > + keep_curr_dev_pwr_mode = hba->auto_bkops_enabled || > + ufshcd_wb_keep_vcc_on(hba); > } > > - if ((req_dev_pwr_mode != hba->curr_dev_pwr_mode) && > - ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) || > - !ufshcd_is_runtime_pm(pm_op))) { > - /* ensure that bkops is disabled */ > - ufshcd_disable_auto_bkops(hba); > - ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode); > - if (ret) > - goto enable_gating; > + if (req_dev_pwr_mode != hba->curr_dev_pwr_mode) { > + if ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) || > + !ufshcd_is_runtime_pm(pm_op)) { > + /* ensure that bkops is disabled */ > + ufshcd_disable_auto_bkops(hba); > + } > + > + if (!keep_curr_dev_pwr_mode) { > + ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode); > + if (ret) > + goto enable_gating; > + } > } > > flush_work(&hba->eeh_work); > Can you please confirm that you've tested and found that with the previous code, the flush operation in the device was not happening. If so, please can you let me know the test-case that you ran to figure this out. I'd like to verify this at my end. -- Thanks, -asd
Hi Asutosh, On Tue, 2020-05-12 at 10:04 -0700, Asutosh Das (asd) wrote: > Hi Stanley, > > On 5/12/2020 3:47 AM, Stanley Chu wrote: > > Currently UFS host driver promises VCC supply if UFS device > > needs to do WriteBooster flush during runtime suspend. > > > > However the UFS specification mentions, > > > > "While the flushing operation is in progress, the device is > > in Active power mode." > > > > Therefore UFS host driver needs to promise more: Keep UFS > > device as "Active power mode", otherwise UFS device shall not > > do any flush if device enters Sleep or PowerDown power mode. > > > > Fix this by not changing device power mode if WriteBooster > > flush is required in ufshcd_suspend(). > > > > Signed-off-by: Stanley Chu <stanley.chu@mediatek.com> > > --- > > drivers/scsi/ufs/ufs.h | 1 - > > drivers/scsi/ufs/ufshcd.c | 39 +++++++++++++++++++-------------------- > > 2 files changed, 19 insertions(+), 21 deletions(-) > > > > diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h > > index b3135344ab3f..9e4bc2e97ada 100644 > > --- a/drivers/scsi/ufs/ufs.h > > +++ b/drivers/scsi/ufs/ufs.h > > @@ -577,7 +577,6 @@ struct ufs_dev_info { > > u32 d_ext_ufs_feature_sup; > > u8 b_wb_buffer_type; > > u32 d_wb_alloc_units; > > - bool keep_vcc_on; > > u8 b_presrv_uspc_en; > > }; > > > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > > index 169a3379e468..2d0aff8ac260 100644 > > --- a/drivers/scsi/ufs/ufshcd.c > > +++ b/drivers/scsi/ufs/ufshcd.c > > @@ -8101,8 +8101,7 @@ static void ufshcd_vreg_set_lpm(struct ufs_hba *hba) > > !hba->dev_info.is_lu_power_on_wp) { > > ufshcd_setup_vreg(hba, false); > > } else if (!ufshcd_is_ufs_dev_active(hba)) { > > - if (!hba->dev_info.keep_vcc_on) > > - ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); > > + ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); > > if (!ufshcd_is_link_active(hba)) { > > ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq); > > ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq2); > > @@ -8172,6 +8171,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) > > enum ufs_pm_level pm_lvl; > > enum ufs_dev_pwr_mode req_dev_pwr_mode; > > enum uic_link_state req_link_state; > > + bool keep_curr_dev_pwr_mode = false; > > > > hba->pm_op_in_progress = 1; > > if (!ufshcd_is_shutdown_pm(pm_op)) { > > @@ -8226,28 +8226,27 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) > > /* make sure that auto bkops is disabled */ > > ufshcd_disable_auto_bkops(hba); > > } > > + > > /* > > - * With wb enabled, if the bkops is enabled or if the > > - * configured WB type is 70% full, keep vcc ON > > - * for the device to flush the wb buffer > > + * If device needs to do BKOP or WB buffer flush, keep device > > + * power mode as "active power mode" and its VCC supply. > > */ > > - if ((hba->auto_bkops_enabled && ufshcd_is_wb_allowed(hba)) || > > - ufshcd_wb_keep_vcc_on(hba)) > > - hba->dev_info.keep_vcc_on = true; > > - else > > - hba->dev_info.keep_vcc_on = false; > > - } else { > > - hba->dev_info.keep_vcc_on = false; > > + keep_curr_dev_pwr_mode = hba->auto_bkops_enabled || > > + ufshcd_wb_keep_vcc_on(hba); > > } > > > > - if ((req_dev_pwr_mode != hba->curr_dev_pwr_mode) && > > - ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) || > > - !ufshcd_is_runtime_pm(pm_op))) { > > - /* ensure that bkops is disabled */ > > - ufshcd_disable_auto_bkops(hba); > > - ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode); > > - if (ret) > > - goto enable_gating; > > + if (req_dev_pwr_mode != hba->curr_dev_pwr_mode) { > > + if ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) || > > + !ufshcd_is_runtime_pm(pm_op)) { > > + /* ensure that bkops is disabled */ > > + ufshcd_disable_auto_bkops(hba); > > + } > > + > > + if (!keep_curr_dev_pwr_mode) { > > + ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode); > > + if (ret) > > + goto enable_gating; > > + } > > } > > > > flush_work(&hba->eeh_work); > > > > Can you please confirm that you've tested and found that with the > previous code, the flush operation in the device was not happening. > > If so, please can you let me know the test-case that you ran to figure > this out. > > I'd like to verify this at my end. Sorry currently I have no easy test cases or scripts available. To precisely confirm the flush behavior by logs, I added some codes to query "available WriteBooster buffer" before entering runtime suspend and after leaving runtime resume, and observe the trend of available WriteBooster buffer. My test steps are as below, 1. Create a writer to write large data in a short time to fill-in WriteBooster buffer. 2. Do something to prevent system suspend 3. Do something to prevent link entering Hibern8, for example, disable Auto-Hibern8 and disable Hibern8 during clock gating. Because the Hibern8 period before runtime-suspend is known that VCC is provided and device can flush WriteBooster buffer if "Flush During H8" is enabled as upstream kernel currently. 4. Shrink the runtime suspend delay (maybe 100ms ~ 200ms) to make runtime suspend happen earlier. 5. After "available WriteBosoter buffer" reaches lower-level, for example, 10%, stop the writer. 6. Observe the trend of WriteBooster available buffer. In the previous code, the available WriteBooster buffer is increased very very slowly. Especially no increasing is observed during runtime-suspend. After applying this fix, the available WriteBooster buffer is increased much faster and the increasing can be easily observed during runtime-suspend. Thanks, Stanley Chu > > -- > Thanks, > -asd >
On 5/12/2020 3:47 AM, Stanley Chu wrote: > Currently UFS host driver promises VCC supply if UFS device > needs to do WriteBooster flush during runtime suspend. > > However the UFS specification mentions, > > "While the flushing operation is in progress, the device is > in Active power mode." > > Therefore UFS host driver needs to promise more: Keep UFS > device as "Active power mode", otherwise UFS device shall not > do any flush if device enters Sleep or PowerDown power mode. > > Fix this by not changing device power mode if WriteBooster > flush is required in ufshcd_suspend(). > > Signed-off-by: Stanley Chu <stanley.chu@mediatek.com> > --- > drivers/scsi/ufs/ufs.h | 1 - > drivers/scsi/ufs/ufshcd.c | 39 +++++++++++++++++++-------------------- > 2 files changed, 19 insertions(+), 21 deletions(-) > > diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h > index b3135344ab3f..9e4bc2e97ada 100644 > --- a/drivers/scsi/ufs/ufs.h > +++ b/drivers/scsi/ufs/ufs.h > @@ -577,7 +577,6 @@ struct ufs_dev_info { > u32 d_ext_ufs_feature_sup; > u8 b_wb_buffer_type; > u32 d_wb_alloc_units; > - bool keep_vcc_on; > u8 b_presrv_uspc_en; > }; > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > index 169a3379e468..2d0aff8ac260 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -8101,8 +8101,7 @@ static void ufshcd_vreg_set_lpm(struct ufs_hba *hba) > !hba->dev_info.is_lu_power_on_wp) { > ufshcd_setup_vreg(hba, false); > } else if (!ufshcd_is_ufs_dev_active(hba)) { > - if (!hba->dev_info.keep_vcc_on) > - ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); > + ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); > if (!ufshcd_is_link_active(hba)) { > ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq); > ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq2); > @@ -8172,6 +8171,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) > enum ufs_pm_level pm_lvl; > enum ufs_dev_pwr_mode req_dev_pwr_mode; > enum uic_link_state req_link_state; > + bool keep_curr_dev_pwr_mode = false; > > hba->pm_op_in_progress = 1; > if (!ufshcd_is_shutdown_pm(pm_op)) { > @@ -8226,28 +8226,27 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) > /* make sure that auto bkops is disabled */ > ufshcd_disable_auto_bkops(hba); > } > + Unnecessary newline, perhaps? > /* > - * With wb enabled, if the bkops is enabled or if the > - * configured WB type is 70% full, keep vcc ON > - * for the device to flush the wb buffer > + * If device needs to do BKOP or WB buffer flush, keep device > + * power mode as "active power mode" and its VCC supply. > */ > - if ((hba->auto_bkops_enabled && ufshcd_is_wb_allowed(hba)) || > - ufshcd_wb_keep_vcc_on(hba)) > - hba->dev_info.keep_vcc_on = true; > - else > - hba->dev_info.keep_vcc_on = false; > - } else { > - hba->dev_info.keep_vcc_on = false; > + keep_curr_dev_pwr_mode = hba->auto_bkops_enabled || > + ufshcd_wb_keep_vcc_on(hba); Should the device be in UFS_ACTIVE_PWR_MODE to perform auto-bkops? Also, is it needed to keep the device in UFS_ACTIVE_PWR_MODE , if flush on hibern8 is enabled and the link is being put to hibern8 mode during runtime-suspend? Perhaps that should also be factored in here? > } > > - if ((req_dev_pwr_mode != hba->curr_dev_pwr_mode) && > - ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) || > - !ufshcd_is_runtime_pm(pm_op))) { > - /* ensure that bkops is disabled */ > - ufshcd_disable_auto_bkops(hba); > - ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode); > - if (ret) > - goto enable_gating; > + if (req_dev_pwr_mode != hba->curr_dev_pwr_mode) { > + if ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) || > + !ufshcd_is_runtime_pm(pm_op)) { > + /* ensure that bkops is disabled */ > + ufshcd_disable_auto_bkops(hba); > + } > + > + if (!keep_curr_dev_pwr_mode) { > + ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode); Now, when the WB buffer is completely flushed out, the device should be put back into UFS_SLEEP_PWR_MODE or UFS_POWERDOWN_PWR_MODE. Say, the device buffer has to be flushed and during runtime-suspend, the device is put to UFS_ACTIVE_PWR_MODE and Vcc is kept ON; the device doesn't resume nor does the system enters suspend for a very long time, and with AH8 and hibern8 disabled, there will be an unnecessary power drain for that much time. How about a periodic interval checking of flush status if keep_curr_dev_pwr_mode evaluates to be true? > + if (ret) > + goto enable_gating; > + } > } > > flush_work(&hba->eeh_work); >
Hi Asutosh, On Wed, 2020-05-13 at 12:31 -0700, Asutosh Das (asd) wrote: > On 5/12/2020 3:47 AM, Stanley Chu wrote: > > Currently UFS host driver promises VCC supply if UFS device > > needs to do WriteBooster flush during runtime suspend. > > > > However the UFS specification mentions, > > > > "While the flushing operation is in progress, the device is > > in Active power mode." > > > > Therefore UFS host driver needs to promise more: Keep UFS > > device as "Active power mode", otherwise UFS device shall not > > do any flush if device enters Sleep or PowerDown power mode. > > > > Fix this by not changing device power mode if WriteBooster > > flush is required in ufshcd_suspend(). > > > > Signed-off-by: Stanley Chu <stanley.chu@mediatek.com> > > --- > > drivers/scsi/ufs/ufs.h | 1 - > > drivers/scsi/ufs/ufshcd.c | 39 +++++++++++++++++++-------------------- > > 2 files changed, 19 insertions(+), 21 deletions(-) > > > > diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h > > index b3135344ab3f..9e4bc2e97ada 100644 > > --- a/drivers/scsi/ufs/ufs.h > > +++ b/drivers/scsi/ufs/ufs.h > > @@ -577,7 +577,6 @@ struct ufs_dev_info { > > u32 d_ext_ufs_feature_sup; > > u8 b_wb_buffer_type; > > u32 d_wb_alloc_units; > > - bool keep_vcc_on; > > u8 b_presrv_uspc_en; > > }; > > > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > > index 169a3379e468..2d0aff8ac260 100644 > > --- a/drivers/scsi/ufs/ufshcd.c > > +++ b/drivers/scsi/ufs/ufshcd.c > > @@ -8101,8 +8101,7 @@ static void ufshcd_vreg_set_lpm(struct ufs_hba *hba) > > !hba->dev_info.is_lu_power_on_wp) { > > ufshcd_setup_vreg(hba, false); > > } else if (!ufshcd_is_ufs_dev_active(hba)) { > > - if (!hba->dev_info.keep_vcc_on) > > - ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); > > + ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); > > if (!ufshcd_is_link_active(hba)) { > > ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq); > > ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq2); > > @@ -8172,6 +8171,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) > > enum ufs_pm_level pm_lvl; > > enum ufs_dev_pwr_mode req_dev_pwr_mode; > > enum uic_link_state req_link_state; > > + bool keep_curr_dev_pwr_mode = false; > > > > hba->pm_op_in_progress = 1; > > if (!ufshcd_is_shutdown_pm(pm_op)) { > > @@ -8226,28 +8226,27 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) > > /* make sure that auto bkops is disabled */ > > ufshcd_disable_auto_bkops(hba); > > } > > + > Unnecessary newline, perhaps? Yap, I will remove it in next version. > > /* > > - * With wb enabled, if the bkops is enabled or if the > > - * configured WB type is 70% full, keep vcc ON > > - * for the device to flush the wb buffer > > + * If device needs to do BKOP or WB buffer flush, keep device > > + * power mode as "active power mode" and its VCC supply. > > */ > > - if ((hba->auto_bkops_enabled && ufshcd_is_wb_allowed(hba)) || > > - ufshcd_wb_keep_vcc_on(hba)) > > - hba->dev_info.keep_vcc_on = true; > > - else > > - hba->dev_info.keep_vcc_on = false; > > - } else { > > - hba->dev_info.keep_vcc_on = false; > > + keep_curr_dev_pwr_mode = hba->auto_bkops_enabled || > > + ufshcd_wb_keep_vcc_on(hba); > Should the device be in UFS_ACTIVE_PWR_MODE to perform auto-bkops? > > Also, is it needed to keep the device in UFS_ACTIVE_PWR_MODE , if flush > on hibern8 is enabled and the link is being put to hibern8 mode during > runtime-suspend? Perhaps that should also be factored in here? Both auto-bkops and WriteBooster flush during Hibern8 need device power mode to be "Active Power Mode". For auto-bkops, the spec mentions, "If the background operations enable bit is set and the device is in Active power mode or Idle power mode, then the device is allowed to execute any internal operations." For WriteBooster flush during Hibern8, the spec mentions, "While the flushing operation is in progress, the device is in Active power mode." Therefore here we can use an unified "keep_curr_dev_pwr_mode" to indicate the same requirements of above both features. Besides, both operations may access flash array inside UFS device thus VCC supply shall be also kept. Before this patch, the original code will keep device power mode (stay in Active Power Mode) if hba->auto_bkops_enabled is set as true during runtime-suspend with UFSHCD_CAP_AUTO_BKOPS_SUSPEND capability is enabled. This patch will not change this decision, just add "WriteBooster flush during Hibern8" feature as another condition to do so. Thank you so much to remind me that "Link shall be put in Hibern8" is a necessary condition for "WriteBooster flush during Hibern8". I will add more checking for keep_curr_dev_pwr_mode to prevent unnecessary power drain. > > } > > > > - if ((req_dev_pwr_mode != hba->curr_dev_pwr_mode) && > > - ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) || > > - !ufshcd_is_runtime_pm(pm_op))) { > > - /* ensure that bkops is disabled */ > > - ufshcd_disable_auto_bkops(hba); > > - ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode); > > - if (ret) > > - goto enable_gating; > > + if (req_dev_pwr_mode != hba->curr_dev_pwr_mode) { > > + if ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) || > > + !ufshcd_is_runtime_pm(pm_op)) { > > + /* ensure that bkops is disabled */ > > + ufshcd_disable_auto_bkops(hba); > > + } > > + > > + if (!keep_curr_dev_pwr_mode) { > > + ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode); > > Now, when the WB buffer is completely flushed out, the device should be > put back into UFS_SLEEP_PWR_MODE or UFS_POWERDOWN_PWR_MODE. Say, the > device buffer has to be flushed and during runtime-suspend, the device > is put to UFS_ACTIVE_PWR_MODE and Vcc is kept ON; the device doesn't > resume nor does the system enters suspend for a very long time, and with > AH8 and hibern8 disabled, there will be an unnecessary power drain for > that much time. > > How about a periodic interval checking of flush status if > keep_curr_dev_pwr_mode evaluates to be true? This is a good point! The same thing also happens for auto-bkops. How about add a timer to leave runtime suspend if keep_curr_dev_pwr_mode is set as true? This is simple and also favors power. The timeout value could be adjustable according to the available WriteBooster buffer size. A periodic interval checking of flush status needs to re-activate link to communicate with the device. This would be tricky and the re-activation flow is just like runtime-resume. What would you think? Thanks. Stanley Chu
Hi Asutosh, On Thu, 2020-05-14 at 10:23 +0800, Stanley Chu wrote: > Hi Asutosh, > > On Wed, 2020-05-13 at 12:31 -0700, Asutosh Das (asd) wrote: > > On 5/12/2020 3:47 AM, Stanley Chu wrote: > > > Currently UFS host driver promises VCC supply if UFS device > > > needs to do WriteBooster flush during runtime suspend. > > > > > > However the UFS specification mentions, > > > > > > "While the flushing operation is in progress, the device is > > > in Active power mode." > > > > > > Therefore UFS host driver needs to promise more: Keep UFS > > > device as "Active power mode", otherwise UFS device shall not > > > do any flush if device enters Sleep or PowerDown power mode. > > > > > > Fix this by not changing device power mode if WriteBooster > > > flush is required in ufshcd_suspend(). > > > > > > Signed-off-by: Stanley Chu <stanley.chu@mediatek.com> > > > --- > > > drivers/scsi/ufs/ufs.h | 1 - > > > drivers/scsi/ufs/ufshcd.c | 39 +++++++++++++++++++-------------------- > > > 2 files changed, 19 insertions(+), 21 deletions(-) > > > > > > diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h > > > index b3135344ab3f..9e4bc2e97ada 100644 > > > --- a/drivers/scsi/ufs/ufs.h > > > +++ b/drivers/scsi/ufs/ufs.h > > > @@ -577,7 +577,6 @@ struct ufs_dev_info { > > > u32 d_ext_ufs_feature_sup; > > > u8 b_wb_buffer_type; > > > u32 d_wb_alloc_units; > > > - bool keep_vcc_on; > > > u8 b_presrv_uspc_en; > > > }; > > > > > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > > > index 169a3379e468..2d0aff8ac260 100644 > > > --- a/drivers/scsi/ufs/ufshcd.c > > > +++ b/drivers/scsi/ufs/ufshcd.c > > > @@ -8101,8 +8101,7 @@ static void ufshcd_vreg_set_lpm(struct ufs_hba *hba) > > > !hba->dev_info.is_lu_power_on_wp) { > > > ufshcd_setup_vreg(hba, false); > > > } else if (!ufshcd_is_ufs_dev_active(hba)) { > > > - if (!hba->dev_info.keep_vcc_on) > > > - ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); > > > + ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); > > > if (!ufshcd_is_link_active(hba)) { > > > ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq); > > > ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq2); > > > @@ -8172,6 +8171,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) > > > enum ufs_pm_level pm_lvl; > > > enum ufs_dev_pwr_mode req_dev_pwr_mode; > > > enum uic_link_state req_link_state; > > > + bool keep_curr_dev_pwr_mode = false; > > > > > > hba->pm_op_in_progress = 1; > > > if (!ufshcd_is_shutdown_pm(pm_op)) { > > > @@ -8226,28 +8226,27 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) > > > /* make sure that auto bkops is disabled */ > > > ufshcd_disable_auto_bkops(hba); > > > } > > > + > > Unnecessary newline, perhaps? > > Yap, I will remove it in next version. > > > > /* > > > - * With wb enabled, if the bkops is enabled or if the > > > - * configured WB type is 70% full, keep vcc ON > > > - * for the device to flush the wb buffer > > > + * If device needs to do BKOP or WB buffer flush, keep device > > > + * power mode as "active power mode" and its VCC supply. > > > */ > > > - if ((hba->auto_bkops_enabled && ufshcd_is_wb_allowed(hba)) || > > > - ufshcd_wb_keep_vcc_on(hba)) > > > - hba->dev_info.keep_vcc_on = true; > > > - else > > > - hba->dev_info.keep_vcc_on = false; > > > - } else { > > > - hba->dev_info.keep_vcc_on = false; > > > + keep_curr_dev_pwr_mode = hba->auto_bkops_enabled || > > > + ufshcd_wb_keep_vcc_on(hba); > > Should the device be in UFS_ACTIVE_PWR_MODE to perform auto-bkops? > > > > Also, is it needed to keep the device in UFS_ACTIVE_PWR_MODE , if flush > > on hibern8 is enabled and the link is being put to hibern8 mode during > > runtime-suspend? Perhaps that should also be factored in here? > > Both auto-bkops and WriteBooster flush during Hibern8 need device power > mode to be "Active Power Mode". > > For auto-bkops, the spec mentions, > > "If the background operations enable bit is set and the device is in > Active power mode or Idle power mode, then the device is allowed to > execute any internal operations." > > For WriteBooster flush during Hibern8, the spec mentions, > > "While the flushing operation is in progress, the device is in Active > power mode." > > Therefore here we can use an unified "keep_curr_dev_pwr_mode" to > indicate the same requirements of above both features. > > Besides, both operations may access flash array inside UFS device thus > VCC supply shall be also kept. > > Before this patch, the original code will keep device power mode (stay > in Active Power Mode) if hba->auto_bkops_enabled is set as true during > runtime-suspend with UFSHCD_CAP_AUTO_BKOPS_SUSPEND capability is > enabled. This patch will not change this decision, just add > "WriteBooster flush during Hibern8" feature as another condition to do > so. > > Thank you so much to remind me that "Link shall be put in Hibern8" is a > necessary condition for "WriteBooster flush during Hibern8". I will add > more checking for keep_curr_dev_pwr_mode to prevent unnecessary power > drain. > > > > } > > > > > > - if ((req_dev_pwr_mode != hba->curr_dev_pwr_mode) && > > > - ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) || > > > - !ufshcd_is_runtime_pm(pm_op))) { > > > - /* ensure that bkops is disabled */ > > > - ufshcd_disable_auto_bkops(hba); > > > - ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode); > > > - if (ret) > > > - goto enable_gating; > > > + if (req_dev_pwr_mode != hba->curr_dev_pwr_mode) { > > > + if ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) || > > > + !ufshcd_is_runtime_pm(pm_op)) { > > > + /* ensure that bkops is disabled */ > > > + ufshcd_disable_auto_bkops(hba); > > > + } > > > + > > > + if (!keep_curr_dev_pwr_mode) { > > > + ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode); > > > > Now, when the WB buffer is completely flushed out, the device should be > > put back into UFS_SLEEP_PWR_MODE or UFS_POWERDOWN_PWR_MODE. Say, the > > device buffer has to be flushed and during runtime-suspend, the device > > is put to UFS_ACTIVE_PWR_MODE and Vcc is kept ON; the device doesn't > > resume nor does the system enters suspend for a very long time, and with > > AH8 and hibern8 disabled, there will be an unnecessary power drain for > > that much time. Another thought is that if keep_curr_dev_pwr_mode will be set as true only if link is put in Hibern8 or Auto-Hibern8 is enabled. By this way, the power consumption shall be very small after flush or auto-bkop is finished. Then the checking of flush status during runtime-suspend may be not necessary. > > > > How about a periodic interval checking of flush status if > > keep_curr_dev_pwr_mode evaluates to be true? > > This is a good point! > > The same thing also happens for auto-bkops. How about add a timer to > leave runtime suspend if keep_curr_dev_pwr_mode is set as true? This is > simple and also favors power. The timeout value could be adjustable > according to the available WriteBooster buffer size. > > A periodic interval checking of flush status needs to re-activate link > to communicate with the device. This would be tricky and the > re-activation flow is just like runtime-resume. > > What would you think? > > Thanks. > Stanley Chu > > > _______________________________________________ > Linux-mediatek mailing list > Linux-mediatek@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-mediatek
On 5/14/2020 7:49 AM, Stanley Chu wrote: > Hi Asutosh, > > On Thu, 2020-05-14 at 10:23 +0800, Stanley Chu wrote: >> Hi Asutosh, >> >> On Wed, 2020-05-13 at 12:31 -0700, Asutosh Das (asd) wrote: >>> On 5/12/2020 3:47 AM, Stanley Chu wrote: >>>> Currently UFS host driver promises VCC supply if UFS device >>>> needs to do WriteBooster flush during runtime suspend. >>>> >>>> However the UFS specification mentions, >>>> >>>> "While the flushing operation is in progress, the device is >>>> in Active power mode." >>>> >>>> Therefore UFS host driver needs to promise more: Keep UFS >>>> device as "Active power mode", otherwise UFS device shall not >>>> do any flush if device enters Sleep or PowerDown power mode. >>>> >>>> Fix this by not changing device power mode if WriteBooster >>>> flush is required in ufshcd_suspend(). >>>> >>>> Signed-off-by: Stanley Chu <stanley.chu@mediatek.com> >>>> --- >>>> drivers/scsi/ufs/ufs.h | 1 - >>>> drivers/scsi/ufs/ufshcd.c | 39 +++++++++++++++++++-------------------- >>>> 2 files changed, 19 insertions(+), 21 deletions(-) >>>> >>>> diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h >>>> index b3135344ab3f..9e4bc2e97ada 100644 >>>> --- a/drivers/scsi/ufs/ufs.h >>>> +++ b/drivers/scsi/ufs/ufs.h >>>> @@ -577,7 +577,6 @@ struct ufs_dev_info { >>>> u32 d_ext_ufs_feature_sup; >>>> u8 b_wb_buffer_type; >>>> u32 d_wb_alloc_units; >>>> - bool keep_vcc_on; >>>> u8 b_presrv_uspc_en; >>>> }; >>>> >>>> diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c >>>> index 169a3379e468..2d0aff8ac260 100644 >>>> --- a/drivers/scsi/ufs/ufshcd.c >>>> +++ b/drivers/scsi/ufs/ufshcd.c >>>> @@ -8101,8 +8101,7 @@ static void ufshcd_vreg_set_lpm(struct ufs_hba *hba) >>>> !hba->dev_info.is_lu_power_on_wp) { >>>> ufshcd_setup_vreg(hba, false); >>>> } else if (!ufshcd_is_ufs_dev_active(hba)) { >>>> - if (!hba->dev_info.keep_vcc_on) >>>> - ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); >>>> + ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); >>>> if (!ufshcd_is_link_active(hba)) { >>>> ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq); >>>> ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq2); >>>> @@ -8172,6 +8171,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) >>>> enum ufs_pm_level pm_lvl; >>>> enum ufs_dev_pwr_mode req_dev_pwr_mode; >>>> enum uic_link_state req_link_state; >>>> + bool keep_curr_dev_pwr_mode = false; >>>> >>>> hba->pm_op_in_progress = 1; >>>> if (!ufshcd_is_shutdown_pm(pm_op)) { >>>> @@ -8226,28 +8226,27 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) >>>> /* make sure that auto bkops is disabled */ >>>> ufshcd_disable_auto_bkops(hba); >>>> } >>>> + >>> Unnecessary newline, perhaps? >> >> Yap, I will remove it in next version. >> >>>> /* >>>> - * With wb enabled, if the bkops is enabled or if the >>>> - * configured WB type is 70% full, keep vcc ON >>>> - * for the device to flush the wb buffer >>>> + * If device needs to do BKOP or WB buffer flush, keep device >>>> + * power mode as "active power mode" and its VCC supply. >>>> */ >>>> - if ((hba->auto_bkops_enabled && ufshcd_is_wb_allowed(hba)) || >>>> - ufshcd_wb_keep_vcc_on(hba)) >>>> - hba->dev_info.keep_vcc_on = true; >>>> - else >>>> - hba->dev_info.keep_vcc_on = false; >>>> - } else { >>>> - hba->dev_info.keep_vcc_on = false; >>>> + keep_curr_dev_pwr_mode = hba->auto_bkops_enabled || >>>> + ufshcd_wb_keep_vcc_on(hba); >>> Should the device be in UFS_ACTIVE_PWR_MODE to perform auto-bkops? >>> >>> Also, is it needed to keep the device in UFS_ACTIVE_PWR_MODE , if flush >>> on hibern8 is enabled and the link is being put to hibern8 mode during >>> runtime-suspend? Perhaps that should also be factored in here? >> >> Both auto-bkops and WriteBooster flush during Hibern8 need device power >> mode to be "Active Power Mode". >> >> For auto-bkops, the spec mentions, >> >> "If the background operations enable bit is set and the device is in >> Active power mode or Idle power mode, then the device is allowed to >> execute any internal operations." >> >> For WriteBooster flush during Hibern8, the spec mentions, >> >> "While the flushing operation is in progress, the device is in Active >> power mode." >> >> Therefore here we can use an unified "keep_curr_dev_pwr_mode" to >> indicate the same requirements of above both features. >> >> Besides, both operations may access flash array inside UFS device thus >> VCC supply shall be also kept. >> >> Before this patch, the original code will keep device power mode (stay >> in Active Power Mode) if hba->auto_bkops_enabled is set as true during >> runtime-suspend with UFSHCD_CAP_AUTO_BKOPS_SUSPEND capability is >> enabled. This patch will not change this decision, just add >> "WriteBooster flush during Hibern8" feature as another condition to do >> so. >> >> Thank you so much to remind me that "Link shall be put in Hibern8" is a >> necessary condition for "WriteBooster flush during Hibern8". I will add >> more checking for keep_curr_dev_pwr_mode to prevent unnecessary power >> drain. >> >>>> } >>>> >>>> - if ((req_dev_pwr_mode != hba->curr_dev_pwr_mode) && >>>> - ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) || >>>> - !ufshcd_is_runtime_pm(pm_op))) { >>>> - /* ensure that bkops is disabled */ >>>> - ufshcd_disable_auto_bkops(hba); >>>> - ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode); >>>> - if (ret) >>>> - goto enable_gating; >>>> + if (req_dev_pwr_mode != hba->curr_dev_pwr_mode) { >>>> + if ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) || >>>> + !ufshcd_is_runtime_pm(pm_op)) { >>>> + /* ensure that bkops is disabled */ >>>> + ufshcd_disable_auto_bkops(hba); >>>> + } >>>> + >>>> + if (!keep_curr_dev_pwr_mode) { >>>> + ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode); >>> >>> Now, when the WB buffer is completely flushed out, the device should be >>> put back into UFS_SLEEP_PWR_MODE or UFS_POWERDOWN_PWR_MODE. Say, the >>> device buffer has to be flushed and during runtime-suspend, the device >>> is put to UFS_ACTIVE_PWR_MODE and Vcc is kept ON; the device doesn't >>> resume nor does the system enters suspend for a very long time, and with >>> AH8 and hibern8 disabled, there will be an unnecessary power drain for >>> that much time. > > Another thought is that if keep_curr_dev_pwr_mode will be set as true > only if link is put in Hibern8 or Auto-Hibern8 is enabled. By this way, > the power consumption shall be very small after flush or auto-bkop is > finished. > > Then the checking of flush status during runtime-suspend may be not > necessary. > >>> >>> How about a periodic interval checking of flush status if >>> keep_curr_dev_pwr_mode evaluates to be true? >> >> This is a good point! >> >> The same thing also happens for auto-bkops. How about add a timer to >> leave runtime suspend if keep_curr_dev_pwr_mode is set as true? This is >> simple and also favors power. The timeout value could be adjustable >> according to the available WriteBooster buffer size. >> >> A periodic interval checking of flush status needs to re-activate link >> to communicate with the device. This would be tricky and the >> re-activation flow is just like runtime-resume. >> >> What would you think? >> >> Thanks. >> Stanley Chu >> >> >> _______________________________________________ >> Linux-mediatek mailing list >> Linux-mediatek@lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-mediatek > Hi Stanley, I think that'd work, but there's definitely a penalty of keeping Vcc ON. And if we do want to keep it ON, then we'd have to measure how much excess power is being used - after the flush is done. I think setting keep_curr_dev_pwr_mode to true iff h8 and ah8 are enabled is a good idea. In addition to that, adding a timer to check flush status if keep_curr_dev_pwr_mode is set to true would keep the power consumption to a minimum. So I suggest to have the delayed check of flush status as well. Thanks, -asd
diff --git a/drivers/scsi/ufs/ufs.h b/drivers/scsi/ufs/ufs.h index b3135344ab3f..9e4bc2e97ada 100644 --- a/drivers/scsi/ufs/ufs.h +++ b/drivers/scsi/ufs/ufs.h @@ -577,7 +577,6 @@ struct ufs_dev_info { u32 d_ext_ufs_feature_sup; u8 b_wb_buffer_type; u32 d_wb_alloc_units; - bool keep_vcc_on; u8 b_presrv_uspc_en; }; diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 169a3379e468..2d0aff8ac260 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -8101,8 +8101,7 @@ static void ufshcd_vreg_set_lpm(struct ufs_hba *hba) !hba->dev_info.is_lu_power_on_wp) { ufshcd_setup_vreg(hba, false); } else if (!ufshcd_is_ufs_dev_active(hba)) { - if (!hba->dev_info.keep_vcc_on) - ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); + ufshcd_toggle_vreg(hba->dev, hba->vreg_info.vcc, false); if (!ufshcd_is_link_active(hba)) { ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq); ufshcd_config_vreg_lpm(hba, hba->vreg_info.vccq2); @@ -8172,6 +8171,7 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) enum ufs_pm_level pm_lvl; enum ufs_dev_pwr_mode req_dev_pwr_mode; enum uic_link_state req_link_state; + bool keep_curr_dev_pwr_mode = false; hba->pm_op_in_progress = 1; if (!ufshcd_is_shutdown_pm(pm_op)) { @@ -8226,28 +8226,27 @@ static int ufshcd_suspend(struct ufs_hba *hba, enum ufs_pm_op pm_op) /* make sure that auto bkops is disabled */ ufshcd_disable_auto_bkops(hba); } + /* - * With wb enabled, if the bkops is enabled or if the - * configured WB type is 70% full, keep vcc ON - * for the device to flush the wb buffer + * If device needs to do BKOP or WB buffer flush, keep device + * power mode as "active power mode" and its VCC supply. */ - if ((hba->auto_bkops_enabled && ufshcd_is_wb_allowed(hba)) || - ufshcd_wb_keep_vcc_on(hba)) - hba->dev_info.keep_vcc_on = true; - else - hba->dev_info.keep_vcc_on = false; - } else { - hba->dev_info.keep_vcc_on = false; + keep_curr_dev_pwr_mode = hba->auto_bkops_enabled || + ufshcd_wb_keep_vcc_on(hba); } - if ((req_dev_pwr_mode != hba->curr_dev_pwr_mode) && - ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) || - !ufshcd_is_runtime_pm(pm_op))) { - /* ensure that bkops is disabled */ - ufshcd_disable_auto_bkops(hba); - ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode); - if (ret) - goto enable_gating; + if (req_dev_pwr_mode != hba->curr_dev_pwr_mode) { + if ((ufshcd_is_runtime_pm(pm_op) && !hba->auto_bkops_enabled) || + !ufshcd_is_runtime_pm(pm_op)) { + /* ensure that bkops is disabled */ + ufshcd_disable_auto_bkops(hba); + } + + if (!keep_curr_dev_pwr_mode) { + ret = ufshcd_set_dev_pwr_mode(hba, req_dev_pwr_mode); + if (ret) + goto enable_gating; + } } flush_work(&hba->eeh_work);
Currently UFS host driver promises VCC supply if UFS device needs to do WriteBooster flush during runtime suspend. However the UFS specification mentions, "While the flushing operation is in progress, the device is in Active power mode." Therefore UFS host driver needs to promise more: Keep UFS device as "Active power mode", otherwise UFS device shall not do any flush if device enters Sleep or PowerDown power mode. Fix this by not changing device power mode if WriteBooster flush is required in ufshcd_suspend(). Signed-off-by: Stanley Chu <stanley.chu@mediatek.com> --- drivers/scsi/ufs/ufs.h | 1 - drivers/scsi/ufs/ufshcd.c | 39 +++++++++++++++++++-------------------- 2 files changed, 19 insertions(+), 21 deletions(-)