* [RFT] i2c: algos: bit: prepare/unprepare before sending initial STOP
@ 2018-06-15 5:17 ` Wolfram Sang
0 siblings, 0 replies; 4+ messages in thread
From: Wolfram Sang @ 2018-06-15 5:17 UTC (permalink / raw)
To: linux-i2c, cerg2010cerg2010; +Cc: linux-renesas-soc, Wolfram Sang, dri-devel
Some adapters need to be prepared/unprepared before bitbanging the bus.
Do this for the initial STOP, too.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
Ok, another idea to fix the regression. I'm not 100% sure if the placement is
perfect, but it should serve well enough as a proof of concept to see if this
is the actual issue. It looks promising, though.
drivers/i2c/algos/i2c-algo-bit.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index 4a34f311e1ff..fab4437ecbb5 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -648,10 +648,19 @@ static int __i2c_bit_add_bus(struct i2c_adapter *adap,
adap->quirks = &i2c_bit_quirk_no_clk_stretch;
/* Bring bus to a known state. Looks like STOP if bus is not free yet */
+ if (bit_adap->pre_xfer) {
+ ret = bit_adap->pre_xfer(adap);
+ if (ret < 0)
+ return ret;
+ }
+
setscl(bit_adap, 1);
udelay(bit_adap->udelay);
setsda(bit_adap, 1);
+ if (bit_adap->post_xfer)
+ bit_adap->post_xfer(adap);
+
ret = add_adapter(adap);
if (ret < 0)
return ret;
--
2.11.0
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^ permalink raw reply related [flat|nested] 4+ messages in thread
* [RFT] i2c: algos: bit: prepare/unprepare before sending initial STOP
@ 2018-06-15 5:17 ` Wolfram Sang
0 siblings, 0 replies; 4+ messages in thread
From: Wolfram Sang @ 2018-06-15 5:17 UTC (permalink / raw)
To: linux-i2c, cerg2010cerg2010; +Cc: linux-renesas-soc, dri-devel, Wolfram Sang
Some adapters need to be prepared/unprepared before bitbanging the bus.
Do this for the initial STOP, too.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
Ok, another idea to fix the regression. I'm not 100% sure if the placement is
perfect, but it should serve well enough as a proof of concept to see if this
is the actual issue. It looks promising, though.
drivers/i2c/algos/i2c-algo-bit.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/drivers/i2c/algos/i2c-algo-bit.c b/drivers/i2c/algos/i2c-algo-bit.c
index 4a34f311e1ff..fab4437ecbb5 100644
--- a/drivers/i2c/algos/i2c-algo-bit.c
+++ b/drivers/i2c/algos/i2c-algo-bit.c
@@ -648,10 +648,19 @@ static int __i2c_bit_add_bus(struct i2c_adapter *adap,
adap->quirks = &i2c_bit_quirk_no_clk_stretch;
/* Bring bus to a known state. Looks like STOP if bus is not free yet */
+ if (bit_adap->pre_xfer) {
+ ret = bit_adap->pre_xfer(adap);
+ if (ret < 0)
+ return ret;
+ }
+
setscl(bit_adap, 1);
udelay(bit_adap->udelay);
setsda(bit_adap, 1);
+ if (bit_adap->post_xfer)
+ bit_adap->post_xfer(adap);
+
ret = add_adapter(adap);
if (ret < 0)
return ret;
--
2.11.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [RFT] i2c: algos: bit: prepare/unprepare before sending initial STOP
2018-06-15 5:17 ` Wolfram Sang
@ 2018-06-15 8:25 ` Sergei Shtylyov
-1 siblings, 0 replies; 4+ messages in thread
From: Sergei Shtylyov @ 2018-06-15 8:25 UTC (permalink / raw)
To: Wolfram Sang, linux-i2c, cerg2010cerg2010; +Cc: linux-renesas-soc, dri-devel
On 6/15/2018 8:17 AM, Wolfram Sang wrote:
> Some adapters need to be prepared/unprepared before bitbanging the bus.
Before/after?
> Do this for the initial STOP, too.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[...]
MBR, Sergei
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https://lists.freedesktop.org/mailman/listinfo/dri-devel
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [RFT] i2c: algos: bit: prepare/unprepare before sending initial STOP
@ 2018-06-15 8:25 ` Sergei Shtylyov
0 siblings, 0 replies; 4+ messages in thread
From: Sergei Shtylyov @ 2018-06-15 8:25 UTC (permalink / raw)
To: Wolfram Sang, linux-i2c, cerg2010cerg2010; +Cc: linux-renesas-soc, dri-devel
On 6/15/2018 8:17 AM, Wolfram Sang wrote:
> Some adapters need to be prepared/unprepared before bitbanging the bus.
Before/after?
> Do this for the initial STOP, too.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
[...]
MBR, Sergei
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-06-15 8:25 UTC | newest]
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2018-06-15 5:17 [RFT] i2c: algos: bit: prepare/unprepare before sending initial STOP Wolfram Sang
2018-06-15 5:17 ` Wolfram Sang
2018-06-15 8:25 ` Sergei Shtylyov
2018-06-15 8:25 ` Sergei Shtylyov
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