| Message ID | 20241212122409.1420962-2-xu.yang_2@nxp.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,1/2] usb: typec: tcpci: fix NULL pointer issue on shared irq case | expand |
On Mon, Dec 16, 2024 at 07:55:40PM +0100, Francesco Dolcini wrote: > On Thu, Dec 12, 2024 at 08:24:09PM +0800, Xu Yang wrote: > > With edge irq support, the ALERT event may be missed currently. The reason > > is that ALERT_MASK register is written before devm_request_threaded_irq(). > > If ALERT event happens in this time gap, it will be missed and ALERT line > > will not recover to high level. However, we can't meet this issue with > > level irq. To avoid the issue, this will add a flag set_alert_mask. So > > ALERT_MASK can be written after devm_request_threaded_irq() is called. The > > behavior of tcpm_init() keeps unchanged. > > > > Fixes: 77e85107a771 ("usb: typec: tcpci: support edge irq") > > Cc: stable@vger.kernel.org > > Signed-off-by: Xu Yang <xu.yang_2@nxp.com> > > I wonder if this should be squashed together with the first commit, > given you re-introduce an issue with the previous commit. No. One patch normally should do one thing. To support edge irq, commit 77e85107a771 cause NULL ponter issue so path 1 fix it, it also didn't handle irq or alert_mask correctly, then patch 2 is needed. > > > > > > --- > > Changes in v2: > > - new patch > > --- > > drivers/usb/typec/tcpm/tcpci.c | 22 +++++++++++++++++----- > > 1 file changed, 17 insertions(+), 5 deletions(-) > > > > diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c > > index db42f4bf3632..836f6d54d267 100644 > > --- a/drivers/usb/typec/tcpm/tcpci.c > > +++ b/drivers/usb/typec/tcpm/tcpci.c > > @@ -37,6 +37,7 @@ struct tcpci { > > unsigned int alert_mask; > > > > bool controls_vbus; > > + bool set_alert_mask; > > > > struct tcpc_dev tcpc; > > struct tcpci_data *data; > > @@ -700,7 +701,10 @@ static int tcpci_init(struct tcpc_dev *tcpc) > > > > tcpci->alert_mask = reg; > > > > - return tcpci_write16(tcpci, TCPC_ALERT_MASK, reg); > > + if (tcpci->set_alert_mask) > > + ret = tcpci_write16(tcpci, TCPC_ALERT_MASK, reg); > > + > > + return ret; > > } > > > > irqreturn_t tcpci_irq(struct tcpci *tcpci) > > @@ -931,12 +935,20 @@ static int tcpci_probe(struct i2c_client *client) > > _tcpci_irq, > > IRQF_SHARED | IRQF_ONESHOT, > > dev_name(&client->dev), chip); > > - if (err < 0) { > > - tcpci_unregister_port(chip->tcpci); > > - return err; > > - } > > + if (err < 0) > > + goto unregister_port; > > > > + /* Enable the interrupt on chip at last */ > > + err = tcpci_write16(chip->tcpci, TCPC_ALERT_MASK, chip->tcpci->alert_mask); > what's the content of alert_mask here? tcpci_register_port() tcpm_register_port() tcpm_init() tcpci_init() tcpci->alert_mask = reg; After tcpci_register_port() completed, alert_mask is assigned a specific value. For example: reg = TCPC_ALERT_TX_SUCCESS | TCPC_ALERT_TX_FAILED | TCPC_ALERT_TX_DISCARDED | TCPC_ALERT_RX_STATUS | TCPC_ALERT_RX_HARD_RST | TCPC_ALERT_CC_STATUS; > > I am not fully understanding why this flag is needed, can't we just ensure > that within probe the alert mask is set to 0, after probe return with > success we have the interrupt handler enabled and we can just write the > alert mask unconditionally. I wrongly thought ALERT_MASK is firstly reset and set again in tcpci_init(). Actually it's not reset, so the flag is not needed. I'll change it later. Thanks, Xu Yang
On Tue, Dec 17, 2024 at 04:54:07PM +0800, Xu Yang wrote: > On Mon, Dec 16, 2024 at 07:55:40PM +0100, Francesco Dolcini wrote: > > On Thu, Dec 12, 2024 at 08:24:09PM +0800, Xu Yang wrote: > > > With edge irq support, the ALERT event may be missed currently. The reason > > > is that ALERT_MASK register is written before devm_request_threaded_irq(). > > > If ALERT event happens in this time gap, it will be missed and ALERT line > > > will not recover to high level. However, we can't meet this issue with > > > level irq. To avoid the issue, this will add a flag set_alert_mask. So > > > ALERT_MASK can be written after devm_request_threaded_irq() is called. The > > > behavior of tcpm_init() keeps unchanged. > > > > > > Fixes: 77e85107a771 ("usb: typec: tcpci: support edge irq") > > > Cc: stable@vger.kernel.org > > > Signed-off-by: Xu Yang <xu.yang_2@nxp.com> > > > > I wonder if this should be squashed together with the first commit, > > given you re-introduce an issue with the previous commit. > > No. One patch normally should do one thing. To support edge irq, commit > 77e85107a771 cause NULL ponter issue so path 1 fix it, it also didn't > handle irq or alert_mask correctly, then patch 2 is needed. Sure. And you also want your commit to be bi-sectable, your first patch introduce a bug to fix another one, and than you fix it in the second one. In any case, Greg will tell if he wants something different here or not. Francesco
diff --git a/drivers/usb/typec/tcpm/tcpci.c b/drivers/usb/typec/tcpm/tcpci.c index db42f4bf3632..836f6d54d267 100644 --- a/drivers/usb/typec/tcpm/tcpci.c +++ b/drivers/usb/typec/tcpm/tcpci.c @@ -37,6 +37,7 @@ struct tcpci { unsigned int alert_mask; bool controls_vbus; + bool set_alert_mask; struct tcpc_dev tcpc; struct tcpci_data *data; @@ -700,7 +701,10 @@ static int tcpci_init(struct tcpc_dev *tcpc) tcpci->alert_mask = reg; - return tcpci_write16(tcpci, TCPC_ALERT_MASK, reg); + if (tcpci->set_alert_mask) + ret = tcpci_write16(tcpci, TCPC_ALERT_MASK, reg); + + return ret; } irqreturn_t tcpci_irq(struct tcpci *tcpci) @@ -931,12 +935,20 @@ static int tcpci_probe(struct i2c_client *client) _tcpci_irq, IRQF_SHARED | IRQF_ONESHOT, dev_name(&client->dev), chip); - if (err < 0) { - tcpci_unregister_port(chip->tcpci); - return err; - } + if (err < 0) + goto unregister_port; + /* Enable the interrupt on chip at last */ + err = tcpci_write16(chip->tcpci, TCPC_ALERT_MASK, chip->tcpci->alert_mask); + if (err < 0) + goto unregister_port; + + chip->tcpci->set_alert_mask = true; return 0; + +unregister_port: + tcpci_unregister_port(chip->tcpci); + return err; } static void tcpci_remove(struct i2c_client *client)
With edge irq support, the ALERT event may be missed currently. The reason is that ALERT_MASK register is written before devm_request_threaded_irq(). If ALERT event happens in this time gap, it will be missed and ALERT line will not recover to high level. However, we can't meet this issue with level irq. To avoid the issue, this will add a flag set_alert_mask. So ALERT_MASK can be written after devm_request_threaded_irq() is called. The behavior of tcpm_init() keeps unchanged. Fixes: 77e85107a771 ("usb: typec: tcpci: support edge irq") Cc: stable@vger.kernel.org Signed-off-by: Xu Yang <xu.yang_2@nxp.com> --- Changes in v2: - new patch --- drivers/usb/typec/tcpm/tcpci.c | 22 +++++++++++++++++----- 1 file changed, 17 insertions(+), 5 deletions(-)