Hello Nishant, Comments inlined: Regards Moiz Sonasath Linux Baseport Team, Dallas 214-567-5514 -----Original Message----- From: Menon, Nishanth Sent: Tuesday, July 14, 2009 5:22 PM To: Sonasath, Moiz; linux-omap@xxxxxxxxxxxxxxx Cc: Kamat, Nishant; Paul Walmsley Subject: RE: [PATCH 2/3] [OMAP:I2C]In case of a NACK|ARDY|AL return from the ISR > -----Original Message----- > From: linux-omap-owner@xxxxxxxxxxxxxxx [mailto:linux-omap- > owner@xxxxxxxxxxxxxxx] On Behalf Of Sonasath, Moiz > Sent: Tuesday, July 14, 2009 4:20 PM > To: linux-omap@xxxxxxxxxxxxxxx > Cc: Kamat, Nishant; Paul Walmsley > Subject: [PATCH 2/3] [OMAP:I2C]In case of a NACK|ARDY|AL return from the > ISR > > > In case of a NACK or ARDY or AL interrupt, complete the request. > There is no need to service the RRDY/RDR or XRDY/XDR interrupts. > > Refer TRM SWPU114: Figure 18-31.I2C Master Transmitter Mode, Interrupt > Method, > in F/S and HS Modes > > http://focus.ti.com/pdfs/wtbu/SWPU114T_PrelimFinalEPDF_06_25_2009.pdf > > Signed-off-by: Moiz Sonasath<m-sonasath@xxxxxx> > Signed-off-by: Vikram Pandita<vikram.pandita@xxxxxx> > --- > drivers/i2c/busses/i2c-omap.c | 4 +++- > 1 files changed, 3 insertions(+), 1 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c > index d280acf..05b5e4c 100644 > --- a/drivers/i2c/busses/i2c-omap.c > +++ b/drivers/i2c/busses/i2c-omap.c > @@ -685,8 +685,10 @@ omap_i2c_isr(int this_irq, void *dev_id) > err |= OMAP_I2C_STAT_AL; > } > if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK | > - OMAP_I2C_STAT_AL)) > + OMAP_I2C_STAT_AL)) { > omap_i2c_complete_cmd(dev, err); > + return IRQ_HANDLED; > + } What is the status of IRQ_STAT register? Who will clear that if we return immediately from ISR? Isr will be reinvoked and we'd handle the same anyways.. [Moiz] Correct me if I am wrong, but you are referring to the OMAP_I2C_STAT_REG (which has the interrupt status information). This is actually ACKED just before going into the NACK|AL|ARDY error cases. I suppose a few days back you also sent out a patch to change this to ACK all interrupts other than RRDY/RDR and XRDY/XDR as we have to ACK these only after we service them. I think this conflicts with [1] [Moiz] Actually, it does not conflict with [1], as [1] changes the later part of the code allowing this patch to be applied cleanly. Regards, Nishanth Menon Ref: [1] http://patchwork.kernel.org/patch/32332/ -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
