[PATCH v7 2/8] ufs: ufs-qcom: Fix race conditions caused by func ufs_qcom_testbus_config

[PATCH v7 2/8] ufs: ufs-qcom: Fix race conditions caused by func ufs_qcom_testbus_config

[Can Guo]

If ufs_qcom_dump_dbg_regs() calls ufs_qcom_testbus_config() from
ufshcd_suspend/resume and/or clk gate/ungate context, pm_runtime_get_sync()
and ufshcd_hold() will cause racing problems. Fix this by removing the
unnecessary calls of pm_runtime_get_sync() and ufshcd_hold().

Signed-off-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Hongwu Su <hongwus@codeaurora.org>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
---
 drivers/scsi/ufs/ufs-qcom.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 2e6ddb5..7da27ee 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -1604,9 +1604,6 @@ int ufs_qcom_testbus_config(struct ufs_qcom_host *host)
 	 */
 	}
 	mask <<= offset;
-
-	pm_runtime_get_sync(host->hba->dev);
-	ufshcd_hold(host->hba, false);
 	ufshcd_rmwl(host->hba, TEST_BUS_SEL,
 		    (u32)host->testbus.select_major << 19,
 		    REG_UFS_CFG1);
@@ -1619,8 +1616,6 @@ int ufs_qcom_testbus_config(struct ufs_qcom_host *host)
 	 * committed before returning.
 	 */
 	mb();
-	ufshcd_release(host->hba);
-	pm_runtime_put_sync(host->hba->dev);
 
 	return 0;
 }
-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

[PATCH v7 3/8] scsi: ufs-qcom: Remove testbus dump in ufs_qcom_dump_dbg_regs

[Can Guo]

Dumping testbus registers is heavy enough to cause stability issues
sometime, just remove them as of now.

Signed-off-by: Can Guo <cang@codeaurora.org>
---
 drivers/scsi/ufs/ufs-qcom.c | 32 --------------------------------
 1 file changed, 32 deletions(-)

diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
index 7da27ee..96e0999 100644
--- a/drivers/scsi/ufs/ufs-qcom.c
+++ b/drivers/scsi/ufs/ufs-qcom.c
@@ -1620,44 +1620,12 @@ int ufs_qcom_testbus_config(struct ufs_qcom_host *host)
 	return 0;
 }
 
-static void ufs_qcom_testbus_read(struct ufs_hba *hba)
-{
-	ufshcd_dump_regs(hba, UFS_TEST_BUS, 4, "UFS_TEST_BUS ");
-}
-
-static void ufs_qcom_print_unipro_testbus(struct ufs_hba *hba)
-{
-	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
-	u32 *testbus = NULL;
-	int i, nminor = 256, testbus_len = nminor * sizeof(u32);
-
-	testbus = kmalloc(testbus_len, GFP_KERNEL);
-	if (!testbus)
-		return;
-
-	host->testbus.select_major = TSTBUS_UNIPRO;
-	for (i = 0; i < nminor; i++) {
-		host->testbus.select_minor = i;
-		ufs_qcom_testbus_config(host);
-		testbus[i] = ufshcd_readl(hba, UFS_TEST_BUS);
-	}
-	print_hex_dump(KERN_ERR, "UNIPRO_TEST_BUS ", DUMP_PREFIX_OFFSET,
-			16, 4, testbus, testbus_len, false);
-	kfree(testbus);
-}
-
 static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba)
 {
 	ufshcd_dump_regs(hba, REG_UFS_SYS1CLK_1US, 16 * 4,
 			 "HCI Vendor Specific Registers ");
 
-	/* sleep a bit intermittently as we are dumping too much data */
 	ufs_qcom_print_hw_debug_reg_all(hba, NULL, ufs_qcom_dump_regs_wrapper);
-	udelay(1000);
-	ufs_qcom_testbus_read(hba);
-	udelay(1000);
-	ufs_qcom_print_unipro_testbus(hba);
-	udelay(1000);
 }
 
 /**
-- 
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.

Re: [PATCH v7 3/8] scsi: ufs-qcom: Remove testbus dump in ufs_qcom_dump_dbg_regs

[hongwus]

On 2020-07-28 13:00, Can Guo wrote:
> Dumping testbus registers is heavy enough to cause stability issues
> sometime, just remove them as of now.
> 
> Signed-off-by: Can Guo <cang@codeaurora.org>
> ---
>  drivers/scsi/ufs/ufs-qcom.c | 32 --------------------------------
>  1 file changed, 32 deletions(-)
> 
> diff --git a/drivers/scsi/ufs/ufs-qcom.c b/drivers/scsi/ufs/ufs-qcom.c
> index 7da27ee..96e0999 100644
> --- a/drivers/scsi/ufs/ufs-qcom.c
> +++ b/drivers/scsi/ufs/ufs-qcom.c
> @@ -1620,44 +1620,12 @@ int ufs_qcom_testbus_config(struct 
> ufs_qcom_host *host)
>  	return 0;
>  }
> 
> -static void ufs_qcom_testbus_read(struct ufs_hba *hba)
> -{
> -	ufshcd_dump_regs(hba, UFS_TEST_BUS, 4, "UFS_TEST_BUS ");
> -}
> -
> -static void ufs_qcom_print_unipro_testbus(struct ufs_hba *hba)
> -{
> -	struct ufs_qcom_host *host = ufshcd_get_variant(hba);
> -	u32 *testbus = NULL;
> -	int i, nminor = 256, testbus_len = nminor * sizeof(u32);
> -
> -	testbus = kmalloc(testbus_len, GFP_KERNEL);
> -	if (!testbus)
> -		return;
> -
> -	host->testbus.select_major = TSTBUS_UNIPRO;
> -	for (i = 0; i < nminor; i++) {
> -		host->testbus.select_minor = i;
> -		ufs_qcom_testbus_config(host);
> -		testbus[i] = ufshcd_readl(hba, UFS_TEST_BUS);
> -	}
> -	print_hex_dump(KERN_ERR, "UNIPRO_TEST_BUS ", DUMP_PREFIX_OFFSET,
> -			16, 4, testbus, testbus_len, false);
> -	kfree(testbus);
> -}
> -
>  static void ufs_qcom_dump_dbg_regs(struct ufs_hba *hba)
>  {
>  	ufshcd_dump_regs(hba, REG_UFS_SYS1CLK_1US, 16 * 4,
>  			 "HCI Vendor Specific Registers ");
> 
> -	/* sleep a bit intermittently as we are dumping too much data */
>  	ufs_qcom_print_hw_debug_reg_all(hba, NULL, 
> ufs_qcom_dump_regs_wrapper);
> -	udelay(1000);
> -	ufs_qcom_testbus_read(hba);
> -	udelay(1000);
> -	ufs_qcom_print_unipro_testbus(hba);
> -	udelay(1000);
>  }
> 
>  /**

Reviewed-by: Hongwu Su <hongwus@codeaurora.org>

RE: [PATCH v7 3/8] scsi: ufs-qcom: Remove testbus dump in ufs_qcom_dump_dbg_regs

[Avri Altman]

> 
> Dumping testbus registers is heavy enough to cause stability issues
> sometime, just remove them as of now.
> 
> Signed-off-by: Can Guo <cang@codeaurora.org>
Reviewed-by: Avri Altman <avri.altman@wdc.com>