* [RFT] i2c: sh_mobile: avoid unnecessary register read
@ 2017-11-09 22:20 Wolfram Sang
2017-11-14 9:10 ` jacopo mondi
2017-11-27 17:56 ` Wolfram Sang
0 siblings, 2 replies; 3+ messages in thread
From: Wolfram Sang @ 2017-11-09 22:20 UTC (permalink / raw)
To: linux-i2c
Cc: linux-renesas-soc, Jacopo Mondi, Yoshihiro Shimoda, Wolfram Sang
There is no data when the first WAIT interrupt arrives. No need to read
something then.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---
I am not super happy with (real pos >= 0) done twice, but I didn't find a
better solution yet. The compiler will make this cheap anyhow, I guess.
Jacopo: can you please test this on top of all other patches?
drivers/i2c/busses/i2c-sh_mobile.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index 80561ffbcf7b46..40a66d466c3c49 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c
@@ -433,8 +433,9 @@ static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
break;
}
data = i2c_op(pd, OP_RX_STOP_DATA, 0);
- } else
+ } else if (real_pos >= 0) {
data = i2c_op(pd, OP_RX, 0);
+ }
if (real_pos >= 0)
pd->msg->buf[real_pos] = data;
--
2.11.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [RFT] i2c: sh_mobile: avoid unnecessary register read
2017-11-09 22:20 [RFT] i2c: sh_mobile: avoid unnecessary register read Wolfram Sang
@ 2017-11-14 9:10 ` jacopo mondi
2017-11-27 17:56 ` Wolfram Sang
1 sibling, 0 replies; 3+ messages in thread
From: jacopo mondi @ 2017-11-14 9:10 UTC (permalink / raw)
To: Wolfram Sang; +Cc: linux-i2c, linux-renesas-soc, Yoshihiro Shimoda
Hi Wolfram,
On Thu, Nov 09, 2017 at 11:20:53PM +0100, Wolfram Sang wrote:
> There is no data when the first WAIT interrupt arrives. No need to read
> something then.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
>
> I am not super happy with (real pos >= 0) done twice, but I didn't find a
> better solution yet. The compiler will make this cheap anyhow, I guess.
>
> Jacopo: can you please test this on top of all other patches?
No regressions on Migo-R during image capture.
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Thanks
j
>
> drivers/i2c/busses/i2c-sh_mobile.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
> index 80561ffbcf7b46..40a66d466c3c49 100644
> --- a/drivers/i2c/busses/i2c-sh_mobile.c
> +++ b/drivers/i2c/busses/i2c-sh_mobile.c
> @@ -433,8 +433,9 @@ static int sh_mobile_i2c_isr_rx(struct sh_mobile_i2c_data *pd)
> break;
> }
> data = i2c_op(pd, OP_RX_STOP_DATA, 0);
> - } else
> + } else if (real_pos >= 0) {
> data = i2c_op(pd, OP_RX, 0);
> + }
>
> if (real_pos >= 0)
> pd->msg->buf[real_pos] = data;
> --
> 2.11.0
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [RFT] i2c: sh_mobile: avoid unnecessary register read
2017-11-09 22:20 [RFT] i2c: sh_mobile: avoid unnecessary register read Wolfram Sang
2017-11-14 9:10 ` jacopo mondi
@ 2017-11-27 17:56 ` Wolfram Sang
1 sibling, 0 replies; 3+ messages in thread
From: Wolfram Sang @ 2017-11-27 17:56 UTC (permalink / raw)
To: Wolfram Sang
Cc: linux-i2c, linux-renesas-soc, Jacopo Mondi, Yoshihiro Shimoda
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On Thu, Nov 09, 2017 at 11:20:53PM +0100, Wolfram Sang wrote:
> There is no data when the first WAIT interrupt arrives. No need to read
> something then.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Applied to for-next, thanks!
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^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-11-09 22:20 [RFT] i2c: sh_mobile: avoid unnecessary register read Wolfram Sang
2017-11-14 9:10 ` jacopo mondi
2017-11-27 17:56 ` Wolfram Sang
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