6.6-stable review patch. If anyone has any objections, please let me know.
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From: Peter Wang peter.wang@mediatek.com
[ Upstream commit 6fd53da45bbc834b9cfdf707d2f7ebe666667943 ]
When ufshcd_clk_scaling_suspend_work (thread A) running and new command coming, ufshcd_clk_scaling_start_busy (thread B) may get host_lock after thread A first time release host_lock. Then thread A second time get host_lock will set clk_scaling.window_start_t = 0 which scale up clock abnormal next polling_ms time. Also inlines another __ufshcd_suspend_clkscaling calls.
Below is racing step: 1 hba->clk_scaling.suspend_work (Thread A) ufshcd_clk_scaling_suspend_work 2 spin_lock_irqsave(hba->host->host_lock, irq_flags); 3 hba->clk_scaling.is_suspended = true; 4 spin_unlock_irqrestore(hba->host->host_lock, irq_flags); __ufshcd_suspend_clkscaling 7 spin_lock_irqsave(hba->host->host_lock, flags); 8 hba->clk_scaling.window_start_t = 0; 9 spin_unlock_irqrestore(hba->host->host_lock, flags);
ufshcd_send_command (Thread B) ufshcd_clk_scaling_start_busy 5 spin_lock_irqsave(hba->host->host_lock, flags); .... 6 spin_unlock_irqrestore(hba->host->host_lock, flags);
Signed-off-by: Peter Wang peter.wang@mediatek.com Link: https://lore.kernel.org/r/20230831130826.5592-3-peter.wang@mediatek.com Reviewed-by: Bart Van Assche bvanassche@acm.org Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Stable-dep-of: 2e083cd80229 ("scsi: ufs: core: Fix clk scaling to be conditional in reset and restore") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/ufs/core/ufshcd.c | 17 ++++------------- 1 file changed, 4 insertions(+), 13 deletions(-)
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index 412931cf240f6..08c46fefb32b4 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -289,7 +289,6 @@ static inline void ufshcd_add_delay_before_dme_cmd(struct ufs_hba *hba); static int ufshcd_host_reset_and_restore(struct ufs_hba *hba); static void ufshcd_resume_clkscaling(struct ufs_hba *hba); static void ufshcd_suspend_clkscaling(struct ufs_hba *hba); -static void __ufshcd_suspend_clkscaling(struct ufs_hba *hba); static int ufshcd_scale_clks(struct ufs_hba *hba, bool scale_up); static irqreturn_t ufshcd_intr(int irq, void *__hba); static int ufshcd_change_power_mode(struct ufs_hba *hba, @@ -1377,9 +1376,10 @@ static void ufshcd_clk_scaling_suspend_work(struct work_struct *work) return; } hba->clk_scaling.is_suspended = true; + hba->clk_scaling.window_start_t = 0; spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
- __ufshcd_suspend_clkscaling(hba); + devfreq_suspend_device(hba->devfreq); }
static void ufshcd_clk_scaling_resume_work(struct work_struct *work) @@ -1556,16 +1556,6 @@ static void ufshcd_devfreq_remove(struct ufs_hba *hba) dev_pm_opp_remove(hba->dev, clki->max_freq); }
-static void __ufshcd_suspend_clkscaling(struct ufs_hba *hba) -{ - unsigned long flags; - - devfreq_suspend_device(hba->devfreq); - spin_lock_irqsave(hba->host->host_lock, flags); - hba->clk_scaling.window_start_t = 0; - spin_unlock_irqrestore(hba->host->host_lock, flags); -} - static void ufshcd_suspend_clkscaling(struct ufs_hba *hba) { unsigned long flags; @@ -1578,11 +1568,12 @@ static void ufshcd_suspend_clkscaling(struct ufs_hba *hba) if (!hba->clk_scaling.is_suspended) { suspend = true; hba->clk_scaling.is_suspended = true; + hba->clk_scaling.window_start_t = 0; } spin_unlock_irqrestore(hba->host->host_lock, flags);
if (suspend) - __ufshcd_suspend_clkscaling(hba); + devfreq_suspend_device(hba->devfreq); }
static void ufshcd_resume_clkscaling(struct ufs_hba *hba)