Tested-by: Raviteja Narayanam <raviteja.narayanam@xxxxxxxxxx>
Thanks
Raviteja N
> -----Original Message-----
> From: linux-i2c-owner@xxxxxxxxxxxxxxx <linux-i2c-owner@xxxxxxxxxxxxxxx> On
> Behalf Of Raviteja Narayanam
> Sent: Friday, June 26, 2020 5:44 PM
> To: Marek Vasut <marex@xxxxxxx>; linux-i2c@xxxxxxxxxxxxxxx
> Cc: Michal Simek <michals@xxxxxxxxxx>; Shubhrajyoti Datta
> <shubhraj@xxxxxxxxxx>; Wolfram Sang <wsa@xxxxxxxxxx>
> Subject: RE: [PATCH 3/5] i2c: xiic: Defer xiic_wakeup() and __xiic_start_xfer() in
> xiic_process()
>
>
>
> > -----Original Message-----
> > From: linux-i2c-owner@xxxxxxxxxxxxxxx
> > <linux-i2c-owner@xxxxxxxxxxxxxxx> On Behalf Of Marek Vasut
> > Sent: Saturday, June 13, 2020 8:38 PM
> > To: linux-i2c@xxxxxxxxxxxxxxx
> > Cc: Marek Vasut <marex@xxxxxxx>; Michal Simek <michals@xxxxxxxxxx>;
> > Shubhrajyoti Datta <shubhraj@xxxxxxxxxx>; Wolfram Sang
> > <wsa@xxxxxxxxxx>
> > Subject: [PATCH 3/5] i2c: xiic: Defer xiic_wakeup() and
> > __xiic_start_xfer() in
> > xiic_process()
> >
> > The __xiic_start_xfer() manipulates the interrupt flags, xiic_wakeup()
> > may result in return from xiic_xfer() early. Defer both to the end of
> > the
> > xiic_process() interrupt thread, so that they are executed after all
> > the other interrupt bits handling completed and once it completely
> > safe to perform changes to the interrupt bits in the hardware.
> >
> > Signed-off-by: Marek Vasut <marex@xxxxxxx>
> > Cc: Michal Simek <michal.simek@xxxxxxxxxx>
> > Cc: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
> > Cc: Wolfram Sang <wsa@xxxxxxxxxx>
> > ---
> > drivers/i2c/busses/i2c-xiic.c | 37
> > ++++++++++++++++++++++++-----------
> > 1 file changed, 26 insertions(+), 11 deletions(-)
> >
> > diff --git a/drivers/i2c/busses/i2c-xiic.c
> > b/drivers/i2c/busses/i2c-xiic.c index
> > 6db71c0fb6583..87eca9d46afd9 100644
> > --- a/drivers/i2c/busses/i2c-xiic.c
> > +++ b/drivers/i2c/busses/i2c-xiic.c
> > @@ -373,6 +373,9 @@ static irqreturn_t xiic_process(int irq, void *dev_id)
> > struct xiic_i2c *i2c = dev_id;
> > u32 pend, isr, ier;
> > u32 clr = 0;
> > + int xfer_more = 0;
> > + int wakeup_req = 0;
> > + int wakeup_code = 0;
> >
> > /* Get the interrupt Status from the IPIF. There is no clearing of
> > * interrupts in the IPIF. Interrupts must be cleared at the source.
> > @@ -409,10 +412,14 @@ static irqreturn_t xiic_process(int irq, void
> *dev_id)
> > */
> > xiic_reinit(i2c);
> >
> > - if (i2c->rx_msg)
> > - xiic_wakeup(i2c, STATE_ERROR);
> > - if (i2c->tx_msg)
> > - xiic_wakeup(i2c, STATE_ERROR);
> > + if (i2c->rx_msg) {
> > + wakeup_req = 1;
> > + wakeup_code = STATE_ERROR;
> > + }
> > + if (i2c->tx_msg) {
> > + wakeup_req = 1;
> > + wakeup_code = STATE_ERROR;
> > + }
> > }
> > if (pend & XIIC_INTR_RX_FULL_MASK) {
> > /* Receive register/FIFO is full */ @@ -446,8 +453,7 @@ static
> > irqreturn_t xiic_process(int irq, void *dev_id)
> > i2c->tx_msg++;
> > dev_dbg(i2c->adap.dev.parent,
> > "%s will start next...\n", __func__);
> > -
> > - __xiic_start_xfer(i2c);
> > + xfer_more = 1;
> > }
> > }
> > }
> > @@ -461,11 +467,13 @@ static irqreturn_t xiic_process(int irq, void
> *dev_id)
> > if (!i2c->tx_msg)
> > goto out;
> >
> > - if ((i2c->nmsgs == 1) && !i2c->rx_msg &&
> > - xiic_tx_space(i2c) == 0)
> > - xiic_wakeup(i2c, STATE_DONE);
> > + wakeup_req = 1;
> > +
> > + if (i2c->nmsgs == 1 && !i2c->rx_msg &&
> > + xiic_tx_space(i2c) == 0)
> > + wakeup_code = STATE_DONE;
> > else
> > - xiic_wakeup(i2c, STATE_ERROR);
> > + wakeup_code = STATE_ERROR;
> > }
> > if (pend & (XIIC_INTR_TX_EMPTY_MASK | XIIC_INTR_TX_HALF_MASK))
> {
> > /* Transmit register/FIFO is empty or ½ empty */ @@ -489,7
> > +497,7 @@ static irqreturn_t xiic_process(int irq, void *dev_id)
> > if (i2c->nmsgs > 1) {
> > i2c->nmsgs--;
> > i2c->tx_msg++;
> > - __xiic_start_xfer(i2c);
> > + xfer_more = 1;
> > } else {
> > xiic_irq_dis(i2c, XIIC_INTR_TX_HALF_MASK);
> >
> > @@ -507,6 +515,13 @@ static irqreturn_t xiic_process(int irq, void *dev_id)
> > dev_dbg(i2c->adap.dev.parent, "%s clr: 0x%x\n", __func__, clr);
> >
> > xiic_setreg32(i2c, XIIC_IISR_OFFSET, clr);
> > + if (xfer_more)
> > + __xiic_start_xfer(i2c);
> > + if (wakeup_req)
> > + xiic_wakeup(i2c, wakeup_code);
> > +
> > + WARN_ON(xfer_more && wakeup_req);
> > +
> > mutex_unlock(&i2c->lock);
> > return IRQ_HANDLED;
> > }
>
> This is tested and working fine.
>
> Raviteja N
