On Tue, Nov 14, 2023 at 01:27:41PM +0800, Qiang Yu wrote:
> From: Hemant Kumar <[email protected]>
>
> If CONFIG_TRACE_IRQFLAGS is enabled, irq will be enabled once __local_bh_
> enable_ip is called as part of write_unlock_bh. Hence, let's take irqsave
"__local_bh_enable_ip" is a function name, so you should not break it.
> lock after TRE is generated to avoid running write_unlock_bh when irqsave
> lock is held.
>
I still don't understand this commit message. Where is the write_unlock_bh()
being called?
- Mani
> Signed-off-by: Hemant Kumar <[email protected]>
> Signed-off-by: Lazarus Motha <[email protected]>
> Signed-off-by: Qiang Yu <[email protected]>
> ---
> drivers/bus/mhi/host/main.c | 13 +++++--------
> 1 file changed, 5 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
> index 33f27e2..d7abd0b 100644
> --- a/drivers/bus/mhi/host/main.c
> +++ b/drivers/bus/mhi/host/main.c
> @@ -1128,17 +1128,15 @@ static int mhi_queue(struct mhi_device *mhi_dev, struct mhi_buf_info *buf_info,
> if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)))
> return -EIO;
>
> - read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
> -
> ret = mhi_is_ring_full(mhi_cntrl, tre_ring);
> - if (unlikely(ret)) {
> - ret = -EAGAIN;
> - goto exit_unlock;
> - }
> + if (unlikely(ret))
> + return -EAGAIN;
>
> ret = mhi_gen_tre(mhi_cntrl, mhi_chan, buf_info, mflags);
> if (unlikely(ret))
> - goto exit_unlock;
> + return ret;
> +
> + read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
>
> /* Packet is queued, take a usage ref to exit M3 if necessary
> * for host->device buffer, balanced put is done on buffer completion
> @@ -1158,7 +1156,6 @@ static int mhi_queue(struct mhi_device *mhi_dev, struct mhi_buf_info *buf_info,
> if (dir == DMA_FROM_DEVICE)
> mhi_cntrl->runtime_put(mhi_cntrl);
>
> -exit_unlock:
> read_unlock_irqrestore(&mhi_cntrl->pm_lock, flags);
>
> return ret;
> --
> 2.7.4
>
>
--
மணிவண்ணன் சதாசிவம்
On 11/24/2023 6:09 PM, Manivannan Sadhasivam wrote:
> On Tue, Nov 14, 2023 at 01:27:41PM +0800, Qiang Yu wrote:
>> From: Hemant Kumar <[email protected]>
>>
>> If CONFIG_TRACE_IRQFLAGS is enabled, irq will be enabled once __local_bh_
>> enable_ip is called as part of write_unlock_bh. Hence, let's take irqsave
> "__local_bh_enable_ip" is a function name, so you should not break it.
Thanks for let me know, will note this in following patch.
>
>> lock after TRE is generated to avoid running write_unlock_bh when irqsave
>> lock is held.
>>
> I still don't understand this commit message. Where is the write_unlock_bh()
> being called?
>
> - Mani
Write_unlock_bh() is invoked in mhi_gen_te()
The calling flow is like
mhi_queue
read_lock_irqsave(&mhi_cntrl->pm_lock, flags)
mhi_gen_tre
write_lock_bh(&mhi_chan->lock)
write_unlock_bh(&mhi_chan->lock) // Will enable irq if
CONFIG_TRACE_IRQFLAGS is enabled
read_lock_irqsave(&mhi_cntrl->pm_lock, flags)
after adding this patch, the calling flow becomes
mhi_queue
mhi_gen_tre
write_lock_bh(&mhi_chan->lock)
write_unlock_bh(&mhi_chan->lock)
read_lock_irqsave(&mhi_cntrl->pm_lock, flags)
read_lock_irqsave(&mhi_cntrl->pm_lock, flags)
>
>> Signed-off-by: Hemant Kumar <[email protected]>
>> Signed-off-by: Lazarus Motha <[email protected]>
>> Signed-off-by: Qiang Yu <[email protected]>
>> ---
>> drivers/bus/mhi/host/main.c | 13 +++++--------
>> 1 file changed, 5 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
>> index 33f27e2..d7abd0b 100644
>> --- a/drivers/bus/mhi/host/main.c
>> +++ b/drivers/bus/mhi/host/main.c
>> @@ -1128,17 +1128,15 @@ static int mhi_queue(struct mhi_device *mhi_dev, struct mhi_buf_info *buf_info,
>> if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)))
>> return -EIO;
>>
>> - read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
>> -
>> ret = mhi_is_ring_full(mhi_cntrl, tre_ring);
>> - if (unlikely(ret)) {
>> - ret = -EAGAIN;
>> - goto exit_unlock;
>> - }
>> + if (unlikely(ret))
>> + return -EAGAIN;
>>
>> ret = mhi_gen_tre(mhi_cntrl, mhi_chan, buf_info, mflags);
>> if (unlikely(ret))
>> - goto exit_unlock;
>> + return ret;
>> +
>> + read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
>>
>> /* Packet is queued, take a usage ref to exit M3 if necessary
>> * for host->device buffer, balanced put is done on buffer completion
>> @@ -1158,7 +1156,6 @@ static int mhi_queue(struct mhi_device *mhi_dev, struct mhi_buf_info *buf_info,
>> if (dir == DMA_FROM_DEVICE)
>> mhi_cntrl->runtime_put(mhi_cntrl);
>>
>> -exit_unlock:
>> read_unlock_irqrestore(&mhi_cntrl->pm_lock, flags);
>>
>> return ret;
>> --
>> 2.7.4
>>
>>
On Mon, Nov 27, 2023 at 03:19:49PM +0800, Qiang Yu wrote:
>
> On 11/24/2023 6:09 PM, Manivannan Sadhasivam wrote:
> > On Tue, Nov 14, 2023 at 01:27:41PM +0800, Qiang Yu wrote:
> > > From: Hemant Kumar <[email protected]>
> > >
> > > If CONFIG_TRACE_IRQFLAGS is enabled, irq will be enabled once __local_bh_
> > > enable_ip is called as part of write_unlock_bh. Hence, let's take irqsave
> > "__local_bh_enable_ip" is a function name, so you should not break it.
> Thanks for let me know, will note this in following patch.
> >
> > > lock after TRE is generated to avoid running write_unlock_bh when irqsave
> > > lock is held.
> > >
> > I still don't understand this commit message. Where is the write_unlock_bh()
> > being called?
> >
> > - Mani
> Write_unlock_bh() is invoked in mhi_gen_te()
> The calling flow is like
> mhi_queue
> read_lock_irqsave(&mhi_cntrl->pm_lock, flags)
> mhi_gen_tre
> write_lock_bh(&mhi_chan->lock)
> write_unlock_bh(&mhi_chan->lock) // Will enable irq if
> CONFIG_TRACE_IRQFLAGS is enabled
> read_lock_irqsave(&mhi_cntrl->pm_lock, flags)
>
> after adding this patch, the calling flow becomes
>
> mhi_queue
> mhi_gen_tre
> write_lock_bh(&mhi_chan->lock)
> write_unlock_bh(&mhi_chan->lock)
> read_lock_irqsave(&mhi_cntrl->pm_lock, flags)
> read_lock_irqsave(&mhi_cntrl->pm_lock, flags)
So this patch essentially fixes the issue caused by patch 1? If so, this should
be squashed into patch 1.
- Mani
> >
> > > Signed-off-by: Hemant Kumar <[email protected]>
> > > Signed-off-by: Lazarus Motha <[email protected]>
> > > Signed-off-by: Qiang Yu <[email protected]>
> > > ---
> > > drivers/bus/mhi/host/main.c | 13 +++++--------
> > > 1 file changed, 5 insertions(+), 8 deletions(-)
> > >
> > > diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
> > > index 33f27e2..d7abd0b 100644
> > > --- a/drivers/bus/mhi/host/main.c
> > > +++ b/drivers/bus/mhi/host/main.c
> > > @@ -1128,17 +1128,15 @@ static int mhi_queue(struct mhi_device *mhi_dev, struct mhi_buf_info *buf_info,
> > > if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)))
> > > return -EIO;
> > > - read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
> > > -
> > > ret = mhi_is_ring_full(mhi_cntrl, tre_ring);
> > > - if (unlikely(ret)) {
> > > - ret = -EAGAIN;
> > > - goto exit_unlock;
> > > - }
> > > + if (unlikely(ret))
> > > + return -EAGAIN;
> > > ret = mhi_gen_tre(mhi_cntrl, mhi_chan, buf_info, mflags);
> > > if (unlikely(ret))
> > > - goto exit_unlock;
> > > + return ret;
> > > +
> > > + read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
> > > /* Packet is queued, take a usage ref to exit M3 if necessary
> > > * for host->device buffer, balanced put is done on buffer completion
> > > @@ -1158,7 +1156,6 @@ static int mhi_queue(struct mhi_device *mhi_dev, struct mhi_buf_info *buf_info,
> > > if (dir == DMA_FROM_DEVICE)
> > > mhi_cntrl->runtime_put(mhi_cntrl);
> > > -exit_unlock:
> > > read_unlock_irqrestore(&mhi_cntrl->pm_lock, flags);
> > > return ret;
> > > --
> > > 2.7.4
> > >
> > >
>
--
மணிவண்ணன் சதாசிவம்
On 12/7/2023 2:38 PM, Manivannan Sadhasivam wrote:
> On Mon, Nov 27, 2023 at 03:19:49PM +0800, Qiang Yu wrote:
>> On 11/24/2023 6:09 PM, Manivannan Sadhasivam wrote:
>>> On Tue, Nov 14, 2023 at 01:27:41PM +0800, Qiang Yu wrote:
>>>> From: Hemant Kumar <[email protected]>
>>>>
>>>> If CONFIG_TRACE_IRQFLAGS is enabled, irq will be enabled once __local_bh_
>>>> enable_ip is called as part of write_unlock_bh. Hence, let's take irqsave
>>> "__local_bh_enable_ip" is a function name, so you should not break it.
>> Thanks for let me know, will note this in following patch.
>>>> lock after TRE is generated to avoid running write_unlock_bh when irqsave
>>>> lock is held.
>>>>
>>> I still don't understand this commit message. Where is the write_unlock_bh()
>>> being called?
>>>
>>> - Mani
>> Write_unlock_bh() is invoked in mhi_gen_te()
>> The calling flow is like
>> mhi_queue
>> read_lock_irqsave(&mhi_cntrl->pm_lock, flags)
>> mhi_gen_tre
>> write_lock_bh(&mhi_chan->lock)
>> write_unlock_bh(&mhi_chan->lock) // Will enable irq if
>> CONFIG_TRACE_IRQFLAGS is enabled
>> read_lock_irqsave(&mhi_cntrl->pm_lock, flags)
>>
>> after adding this patch, the calling flow becomes
>>
>> mhi_queue
>> mhi_gen_tre
>> write_lock_bh(&mhi_chan->lock)
>> write_unlock_bh(&mhi_chan->lock)
>> read_lock_irqsave(&mhi_cntrl->pm_lock, flags)
>> read_lock_irqsave(&mhi_cntrl->pm_lock, flags)
> So this patch essentially fixes the issue caused by patch 1? If so, this should
> be squashed into patch 1.
>
> - Mani
Yes, this patch is to fix the issue caused by patch 1. Will squash patch
1 and this patch into one patch
in next version.
>
>>>> Signed-off-by: Hemant Kumar <[email protected]>
>>>> Signed-off-by: Lazarus Motha <[email protected]>
>>>> Signed-off-by: Qiang Yu <[email protected]>
>>>> ---
>>>> drivers/bus/mhi/host/main.c | 13 +++++--------
>>>> 1 file changed, 5 insertions(+), 8 deletions(-)
>>>>
>>>> diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
>>>> index 33f27e2..d7abd0b 100644
>>>> --- a/drivers/bus/mhi/host/main.c
>>>> +++ b/drivers/bus/mhi/host/main.c
>>>> @@ -1128,17 +1128,15 @@ static int mhi_queue(struct mhi_device *mhi_dev, struct mhi_buf_info *buf_info,
>>>> if (unlikely(MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)))
>>>> return -EIO;
>>>> - read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
>>>> -
>>>> ret = mhi_is_ring_full(mhi_cntrl, tre_ring);
>>>> - if (unlikely(ret)) {
>>>> - ret = -EAGAIN;
>>>> - goto exit_unlock;
>>>> - }
>>>> + if (unlikely(ret))
>>>> + return -EAGAIN;
>>>> ret = mhi_gen_tre(mhi_cntrl, mhi_chan, buf_info, mflags);
>>>> if (unlikely(ret))
>>>> - goto exit_unlock;
>>>> + return ret;
>>>> +
>>>> + read_lock_irqsave(&mhi_cntrl->pm_lock, flags);
>>>> /* Packet is queued, take a usage ref to exit M3 if necessary
>>>> * for host->device buffer, balanced put is done on buffer completion
>>>> @@ -1158,7 +1156,6 @@ static int mhi_queue(struct mhi_device *mhi_dev, struct mhi_buf_info *buf_info,
>>>> if (dir == DMA_FROM_DEVICE)
>>>> mhi_cntrl->runtime_put(mhi_cntrl);
>>>> -exit_unlock:
>>>> read_unlock_irqrestore(&mhi_cntrl->pm_lock, flags);
>>>> return ret;
>>>> --
>>>> 2.7.4
>>>>
>>>>