| Message ID | 20180709094304.8814-4-esben.haabendal@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | i2c: imx: Fix and enable DMA support for LS1021A | expand |
On Mon, Jul 09, 2018 at 11:43:03AM +0200, Esben Haabendal wrote: > From: Esben Haabendal <eha@deif.com> > > Always update the stopped state when busy status have been checked. > This is identical to what was done before, with the exception of error > handling. > Without this change, some errors cause the stopped state to be left in > incorrect state in i2c_imx_stop(), i2c_imx_dma_read(), i2c_imx_read() and > i2c_imx_xfer(). > > Signed-off-by: Esben Haabendal <eha@deif.com> > --- > drivers/i2c/busses/i2c-imx.c | 12 ++++++------ > 1 file changed, 6 insertions(+), 6 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > index d86f152176a4..1db8e6790afc 100644 > --- a/drivers/i2c/busses/i2c-imx.c > +++ b/drivers/i2c/busses/i2c-imx.c > @@ -421,10 +421,14 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy) > return -EAGAIN; > } > > - if (for_busy && (temp & I2SR_IBB)) > + if (for_busy && (temp & I2SR_IBB)) { > + i2c_imx->stopped = 0; > break; > - if (!for_busy && !(temp & I2SR_IBB)) > + } > + if (!for_busy && !(temp & I2SR_IBB)) { > + i2c_imx->stopped = 1; > break; > + } Would it make sense to assign to ->stopped independent of for_busy? > if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) { > dev_dbg(&i2c_imx->adapter.dev, > "<%s> I2C bus is busy\n", __func__); > @@ -538,7 +542,6 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx) > result = i2c_imx_bus_busy(i2c_imx, 1); > if (result) > return result; > - i2c_imx->stopped = 0; > > temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK; > temp &= ~I2CR_DMAEN; > @@ -569,7 +572,6 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx) > > if (!i2c_imx->stopped) { > i2c_imx_bus_busy(i2c_imx, 0); > - i2c_imx->stopped = 1; > } The braces can go away here. > > /* Disable I2C controller */ Best regards Uwe
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> writes: > On Mon, Jul 09, 2018 at 11:43:03AM +0200, Esben Haabendal wrote: >> From: Esben Haabendal <eha@deif.com> >> >> Always update the stopped state when busy status have been checked. >> This is identical to what was done before, with the exception of error >> handling. >> Without this change, some errors cause the stopped state to be left in >> incorrect state in i2c_imx_stop(), i2c_imx_dma_read(), i2c_imx_read() and >> i2c_imx_xfer(). >> >> Signed-off-by: Esben Haabendal <eha@deif.com> >> --- >> drivers/i2c/busses/i2c-imx.c | 12 ++++++------ >> 1 file changed, 6 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c >> index d86f152176a4..1db8e6790afc 100644 >> --- a/drivers/i2c/busses/i2c-imx.c >> +++ b/drivers/i2c/busses/i2c-imx.c >> @@ -421,10 +421,14 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy) >> return -EAGAIN; >> } >> >> - if (for_busy && (temp & I2SR_IBB)) >> + if (for_busy && (temp & I2SR_IBB)) { >> + i2c_imx->stopped = 0; >> break; >> - if (!for_busy && !(temp & I2SR_IBB)) >> + } >> + if (!for_busy && !(temp & I2SR_IBB)) { >> + i2c_imx->stopped = 1; >> break; >> + } > > Would it make sense to assign to ->stopped independent of for_busy? What do you mean? Assigning to ->stopped on each check for I2SR_IBB in loop, independent of the for_busy argument? I don't think so. The additional assignments would be to the same value as it is set to already. >> if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) { >> dev_dbg(&i2c_imx->adapter.dev, >> "<%s> I2C bus is busy\n", __func__); >> @@ -538,7 +542,6 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx) >> result = i2c_imx_bus_busy(i2c_imx, 1); >> if (result) >> return result; >> - i2c_imx->stopped = 0; >> >> temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK; >> temp &= ~I2CR_DMAEN; >> @@ -569,7 +572,6 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx) >> >> if (!i2c_imx->stopped) { >> i2c_imx_bus_busy(i2c_imx, 0); >> - i2c_imx->stopped = 1; >> } > > The braces can go away here. Will do. /Esben
On Thu, Aug 09, 2018 at 02:06:43PM +0200, Esben Haabendal wrote: > Uwe Kleine-König <u.kleine-koenig@pengutronix.de> writes: > > > On Mon, Jul 09, 2018 at 11:43:03AM +0200, Esben Haabendal wrote: > >> From: Esben Haabendal <eha@deif.com> > >> > >> Always update the stopped state when busy status have been checked. > >> This is identical to what was done before, with the exception of error > >> handling. > >> Without this change, some errors cause the stopped state to be left in > >> incorrect state in i2c_imx_stop(), i2c_imx_dma_read(), i2c_imx_read() and > >> i2c_imx_xfer(). > >> > >> Signed-off-by: Esben Haabendal <eha@deif.com> > >> --- > >> drivers/i2c/busses/i2c-imx.c | 12 ++++++------ > >> 1 file changed, 6 insertions(+), 6 deletions(-) > >> > >> diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c > >> index d86f152176a4..1db8e6790afc 100644 > >> --- a/drivers/i2c/busses/i2c-imx.c > >> +++ b/drivers/i2c/busses/i2c-imx.c > >> @@ -421,10 +421,14 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy) > >> return -EAGAIN; > >> } > >> > >> - if (for_busy && (temp & I2SR_IBB)) > >> + if (for_busy && (temp & I2SR_IBB)) { > >> + i2c_imx->stopped = 0; > >> break; > >> - if (!for_busy && !(temp & I2SR_IBB)) > >> + } > >> + if (!for_busy && !(temp & I2SR_IBB)) { > >> + i2c_imx->stopped = 1; > >> break; > >> + } > > > > Would it make sense to assign to ->stopped independent of for_busy? > > What do you mean? > > Assigning to ->stopped on each check for I2SR_IBB in loop, independent > of the for_busy argument? I don't think so. The additional assignments > would be to the same value as it is set to already. Currently you have: if (for_busy && (temp & I2SR_IBB)) { i2c_imx->stopped = 0; break; } if (!for_busy && !(temp & I2SR_IBB)) { i2c_imx->stopped = 1; break; } The semantic of this is the same (apart from always updating .stopped) but is imho easier: i2c_imx->stopped = !(temp & I2SR_IBB); if (for_busy != i2c_imx->stopped) break; Best regards Uwe
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> writes: > On Thu, Aug 09, 2018 at 02:06:43PM +0200, Esben Haabendal wrote: >> Uwe Kleine-König <u.kleine-koenig@pengutronix.de> writes: >> >> > On Mon, Jul 09, 2018 at 11:43:03AM +0200, Esben Haabendal wrote: >> >> From: Esben Haabendal <eha@deif.com> >> >> >> >> Always update the stopped state when busy status have been checked. >> >> This is identical to what was done before, with the exception of error >> >> handling. >> >> Without this change, some errors cause the stopped state to be left in >> >> incorrect state in i2c_imx_stop(), i2c_imx_dma_read(), i2c_imx_read() and >> >> i2c_imx_xfer(). >> >> >> >> Signed-off-by: Esben Haabendal <eha@deif.com> >> >> --- >> >> drivers/i2c/busses/i2c-imx.c | 12 ++++++------ >> >> 1 file changed, 6 insertions(+), 6 deletions(-) >> >> >> >> diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c >> >> index d86f152176a4..1db8e6790afc 100644 >> >> --- a/drivers/i2c/busses/i2c-imx.c >> >> +++ b/drivers/i2c/busses/i2c-imx.c >> >> @@ -421,10 +421,14 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy) >> >> return -EAGAIN; >> >> } >> >> >> >> - if (for_busy && (temp & I2SR_IBB)) >> >> + if (for_busy && (temp & I2SR_IBB)) { >> >> + i2c_imx->stopped = 0; >> >> break; >> >> - if (!for_busy && !(temp & I2SR_IBB)) >> >> + } >> >> + if (!for_busy && !(temp & I2SR_IBB)) { >> >> + i2c_imx->stopped = 1; >> >> break; >> >> + } >> > >> > Would it make sense to assign to ->stopped independent of for_busy? >> >> What do you mean? >> >> Assigning to ->stopped on each check for I2SR_IBB in loop, independent >> of the for_busy argument? I don't think so. The additional assignments >> would be to the same value as it is set to already. > > Currently you have: > > if (for_busy && (temp & I2SR_IBB)) { > i2c_imx->stopped = 0; > break; > } > > if (!for_busy && !(temp & I2SR_IBB)) { > i2c_imx->stopped = 1; > break; > } > > The semantic of this is the same (apart from always updating .stopped) > but is imho easier: > > i2c_imx->stopped = !(temp & I2SR_IBB); > > if (for_busy != i2c_imx->stopped) > break; Yes, that should work also. Shorter, but IMHO a bit more convoluted to read. Let me know if I should send a new version with this change. /Esben
Hello Esben, On Fri, Aug 10, 2018 at 11:25:34AM +0200, Esben Haabendal wrote: > Uwe Kleine-König <u.kleine-koenig@pengutronix.de> writes: > > Currently you have: > > > > if (for_busy && (temp & I2SR_IBB)) { > > i2c_imx->stopped = 0; > > break; > > } > > > > if (!for_busy && !(temp & I2SR_IBB)) { > > i2c_imx->stopped = 1; > > break; > > } > > > > The semantic of this is the same (apart from always updating .stopped) > > but is imho easier: > > > > i2c_imx->stopped = !(temp & I2SR_IBB); > > > > if (for_busy != i2c_imx->stopped) > > break; > > Yes, that should work also. > Shorter, but IMHO a bit more convoluted to read. > Let me know if I should send a new version with this change. unless someone else chimes in I'd say keep it as is. I'd prefer my variant, but I accept that this is something subjective. Best regards Uwe
diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index d86f152176a4..1db8e6790afc 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -421,10 +421,14 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy) return -EAGAIN; } - if (for_busy && (temp & I2SR_IBB)) + if (for_busy && (temp & I2SR_IBB)) { + i2c_imx->stopped = 0; break; - if (!for_busy && !(temp & I2SR_IBB)) + } + if (!for_busy && !(temp & I2SR_IBB)) { + i2c_imx->stopped = 1; break; + } if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) { dev_dbg(&i2c_imx->adapter.dev, "<%s> I2C bus is busy\n", __func__); @@ -538,7 +542,6 @@ static int i2c_imx_start(struct imx_i2c_struct *i2c_imx) result = i2c_imx_bus_busy(i2c_imx, 1); if (result) return result; - i2c_imx->stopped = 0; temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK; temp &= ~I2CR_DMAEN; @@ -569,7 +572,6 @@ static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx) if (!i2c_imx->stopped) { i2c_imx_bus_busy(i2c_imx, 0); - i2c_imx->stopped = 1; } /* Disable I2C controller */ @@ -724,7 +726,6 @@ static int i2c_imx_dma_read(struct imx_i2c_struct *i2c_imx, temp &= ~(I2CR_MSTA | I2CR_MTX); imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); i2c_imx_bus_busy(i2c_imx, 0); - i2c_imx->stopped = 1; } else { /* * For i2c master receiver repeat restart operation like: @@ -852,7 +853,6 @@ static int i2c_imx_read(struct imx_i2c_struct *i2c_imx, struct i2c_msg *msgs, bo temp &= ~(I2CR_MSTA | I2CR_MTX); imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR); i2c_imx_bus_busy(i2c_imx, 0); - i2c_imx->stopped = 1; } else { /* * For i2c master receiver repeat restart operation like: