| Message ID | 1843756.qQiZLxsyqD@wasted.cogentembedded.com (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Headers | show |
On Tue, Sep 02, 2014 at 01:15:26AM +0400, Sergei Shtylyov wrote: > Sometimes the MNR and MST interrupts happen simultaneously (stop automatically > follows NACK, according to the manuals) and in such case the ID_NACK flag isn't > set since the MST interrupt handling precedes MNR and all interrupts are cleared > and disabled then, so that MNR interrupt is never noticed -- this causes NACK'ed > transfers to be falsely reported as successful. Exchanging MNR and MST handlers > fixes this issue, however the MNR bit somehow gets set again even after being > explicitly cleared, so I decided to completely suppress handling of all disabled > interrupts (which is a good thing anyway)... > > Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> > Cc: stable@vger.kernel.org > Applied to for-current, thanks!
On 09/02/2014 01:15 AM, Sergei Shtylyov wrote: > Sometimes the MNR and MST interrupts happen simultaneously (stop automatically > follows NACK, according to the manuals) and in such case the ID_NACK flag isn't > set since the MST interrupt handling precedes MNR and all interrupts are cleared > and disabled then, so that MNR interrupt is never noticed -- this causes NACK'ed > transfers to be falsely reported as successful. Exchanging MNR and MST handlers > fixes this issue, however the MNR bit somehow gets set again even after being > explicitly cleared, so I decided to completely suppress handling of all disabled > interrupts (which is a good thing anyway)... > Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> > Cc: stable@vger.kernel.org > --- > The patch is against Wolfram Sang's 'linux.git' repo. > drivers/i2c/busses/i2c-rcar.c | 15 +++++++++------ > 1 file changed, 9 insertions(+), 6 deletions(-) > > Index: linux/drivers/i2c/busses/i2c-rcar.c > =================================================================== > --- linux.orig/drivers/i2c/busses/i2c-rcar.c > +++ linux/drivers/i2c/busses/i2c-rcar.c > @@ -367,18 +367,15 @@ static irqreturn_t rcar_i2c_irq(int irq, > > msr = rcar_i2c_read(priv, ICMSR); > > + /* Only handle interrupts that are currently enabled */ > + msr &= rcar_i2c_read(priv, ICMIER); > + I think it makes sense to check 'msr' for 0 and return IRQ_NONE in this case. Would you apply such patch (probably to the -next branch)? WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Index: linux/drivers/i2c/busses/i2c-rcar.c =================================================================== --- linux.orig/drivers/i2c/busses/i2c-rcar.c +++ linux/drivers/i2c/busses/i2c-rcar.c @@ -367,18 +367,15 @@ static irqreturn_t rcar_i2c_irq(int irq, msr = rcar_i2c_read(priv, ICMSR); + /* Only handle interrupts that are currently enabled */ + msr &= rcar_i2c_read(priv, ICMIER); + /* Arbitration lost */ if (msr & MAL) { rcar_i2c_flags_set(priv, (ID_DONE | ID_ARBLOST)); goto out; } - /* Stop */ - if (msr & MST) { - rcar_i2c_flags_set(priv, ID_DONE); - goto out; - } - /* Nack */ if (msr & MNR) { /* go to stop phase */ @@ -388,6 +385,12 @@ static irqreturn_t rcar_i2c_irq(int irq, goto out; } + /* Stop */ + if (msr & MST) { + rcar_i2c_flags_set(priv, ID_DONE); + goto out; + } + if (rcar_i2c_is_recv(priv)) rcar_i2c_flags_set(priv, rcar_i2c_irq_recv(priv, msr)); else
Sometimes the MNR and MST interrupts happen simultaneously (stop automatically follows NACK, according to the manuals) and in such case the ID_NACK flag isn't set since the MST interrupt handling precedes MNR and all interrupts are cleared and disabled then, so that MNR interrupt is never noticed -- this causes NACK'ed transfers to be falsely reported as successful. Exchanging MNR and MST handlers fixes this issue, however the MNR bit somehow gets set again even after being explicitly cleared, so I decided to completely suppress handling of all disabled interrupts (which is a good thing anyway)... Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Cc: stable@vger.kernel.org --- The patch is against Wolfram Sang's 'linux.git' repo. drivers/i2c/busses/i2c-rcar.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-sh" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html