evie/android_kernel_oneplus_msm8998
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USB: phy-msm-qusb: Fix race conditions during fast PI/PO

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During fast cable connect/disconnect, there is chance that
set_suspend() called as part of USB entering low power mode
and PMIC driver asking to remove pulldowns race each other.
This could cause unclocked access and results in crash. Fix this
issue by using mutex to avoid crash due to the race mentioned.

Change-Id: I1babb545d40b8761774cbdd3a57258ed6bc77398
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>
This commit is contained in:
Vijayavardhan Vennapusa 2017-02-03 11:42:36 +05:30
parent 3a7e752617
commit 040d3c988c
1 changed files with 10 additions and 1 deletions
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11
drivers/usb/phy/phy-msm-qusb.c
View file

@ -151,6 +151,7 @@ struct qusb_phy {
int *emu_dcm_reset_seq;
int emu_dcm_reset_seq_len;
bool put_into_high_z_state;
struct mutex phy_lock;
};
static void qusb_phy_enable_clocks(struct qusb_phy *qphy, bool on)
@ -326,6 +327,7 @@ static int qusb_phy_update_dpdm(struct usb_phy *phy, int value)
switch (value) {
case POWER_SUPPLY_DP_DM_DPF_DMF:
dev_dbg(phy->dev, "POWER_SUPPLY_DP_DM_DPF_DMF\n");
mutex_lock(&qphy->phy_lock);
if (!qphy->rm_pulldown) {
ret = qusb_phy_enable_power(qphy, true);
if (ret >= 0) {
@ -372,14 +374,17 @@ static int qusb_phy_update_dpdm(struct usb_phy *phy, int value)
/* Make sure that above write is completed */
wmb();
qusb_phy_enable_clocks(qphy, false);
if (qphy->suspended)
qusb_phy_enable_clocks(qphy, false);
}
}
mutex_unlock(&qphy->phy_lock);
break;
case POWER_SUPPLY_DP_DM_DPR_DMR:
dev_dbg(phy->dev, "POWER_SUPPLY_DP_DM_DPR_DMR\n");
mutex_lock(&qphy->phy_lock);
if (qphy->rm_pulldown) {
if (!qphy->cable_connected) {
if (qphy->tcsr_clamp_dig_n)
@ -394,6 +399,7 @@ static int qusb_phy_update_dpdm(struct usb_phy *phy, int value)
qphy->rm_pulldown);
}
}
mutex_unlock(&qphy->phy_lock);
break;
default:
@ -707,6 +713,7 @@ static int qusb_phy_set_suspend(struct usb_phy *phy, int suspend)
qusb_phy_enable_clocks(qphy, false);
} else { /* Disconnect case */
mutex_lock(&qphy->phy_lock);
/* Disable all interrupts */
writel_relaxed(0x00,
qphy->base + QUSB2PHY_PORT_INTR_CTRL);
@ -723,6 +730,7 @@ static int qusb_phy_set_suspend(struct usb_phy *phy, int suspend)
qusb_phy_enable_power(qphy, false);
else
dev_dbg(phy->dev, "race with rm_pulldown. Keep ldo ON\n");
mutex_unlock(&qphy->phy_lock);
/*
* Set put_into_high_z_state to true so next USB
@ -1081,6 +1089,7 @@ static int qusb_phy_probe(struct platform_device *pdev)
return PTR_ERR(qphy->vdda18);
}
mutex_init(&qphy->phy_lock);
platform_set_drvdata(pdev, qphy);
qphy->phy.label = "msm-qusb-phy";