From: Krzysztof Kozlowski <krzk@kernel.org>
To: Lukasz Stelmach <l.stelmach@samsung.com>
Cc: Kukjin Kim <kgene@kernel.org>, Andi Shyti <andi@etezian.org>,
Mark Brown <broonie@kernel.org>,
linux-spi@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, m.szyprowski@samsung.com,
b.zolnierkie@samsung.com
Subject: Re: [PATCH 7/8] spi: spi-s3c64xx: Increase transfer timeout
Date: Fri, 21 Aug 2020 09:10:30 +0200 [thread overview]
Message-ID: <20200821071030.GA8585@kozik-lap> (raw)
In-Reply-To: <dleftjblj621qr.fsf%l.stelmach@samsung.com>
On Wed, Aug 19, 2020 at 03:39:56PM +0200, Lukasz Stelmach wrote:
> It was <2020-08-19 śro 14:49>, when Krzysztof Kozlowski wrote:
> > On Wed, Aug 19, 2020 at 02:32:07PM +0200, Łukasz Stelmach wrote:
> >> Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
> >
> > Why? Everything works fine and suddenly minimum timeout is 100 ms?
>
> Actually I am not 100% sure the max() call is required, maybe +30 is
> enough. Definitely some minimum value is required because for small
> tranfers (100s of bytes) ms is 0 after the first assignment.
Sure, just please describe it all in commit msg. All these questions
"why?" came because of lack of explanation in commit msg.
I guess minimum timeout 100 ms for each transfer is quite high, so maybe
just bump the tolerance to 30 which also would be a minimum timeout.
Best regards,
Krzysztof
>
> >> ---
> >> drivers/spi/spi-s3c64xx.c | 3 ++-
> >> 1 file changed, 2 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
> >> index 27d77600a820..27db1e0f6f32 100644
> >> --- a/drivers/spi/spi-s3c64xx.c
> >> +++ b/drivers/spi/spi-s3c64xx.c
> >> @@ -464,7 +464,8 @@ static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
> >>
> >> /* millisecs to xfer 'len' bytes @ 'cur_speed' */
> >> ms = xfer->len * 8 * 1000 / sdd->cur_speed;
> >> - ms += 10; /* some tolerance */
> >> + ms = (ms * 10) + 30; /* some tolerance */
> >> + ms = max(ms, 100); /* minimum timeout */
> >>
> >> val = msecs_to_jiffies(ms) + 10;
> >> val = wait_for_completion_timeout(&sdd->xfer_completion, val);
> >> --
> >> 2.26.2
> >>
> >
> >
>
> --
> Łukasz Stelmach
> Samsung R&D Institute Poland
> Samsung Electronics
WARNING: multiple messages have this Message-ID (diff)
From: Krzysztof Kozlowski <krzk@kernel.org>
To: Lukasz Stelmach <l.stelmach@samsung.com>
Cc: linux-samsung-soc@vger.kernel.org, b.zolnierkie@samsung.com,
linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org,
Mark Brown <broonie@kernel.org>, Kukjin Kim <kgene@kernel.org>,
Andi Shyti <andi@etezian.org>,
linux-arm-kernel@lists.infradead.org, m.szyprowski@samsung.com
Subject: Re: [PATCH 7/8] spi: spi-s3c64xx: Increase transfer timeout
Date: Fri, 21 Aug 2020 09:10:30 +0200 [thread overview]
Message-ID: <20200821071030.GA8585@kozik-lap> (raw)
In-Reply-To: <dleftjblj621qr.fsf%l.stelmach@samsung.com>
On Wed, Aug 19, 2020 at 03:39:56PM +0200, Lukasz Stelmach wrote:
> It was <2020-08-19 śro 14:49>, when Krzysztof Kozlowski wrote:
> > On Wed, Aug 19, 2020 at 02:32:07PM +0200, Łukasz Stelmach wrote:
> >> Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
> >
> > Why? Everything works fine and suddenly minimum timeout is 100 ms?
>
> Actually I am not 100% sure the max() call is required, maybe +30 is
> enough. Definitely some minimum value is required because for small
> tranfers (100s of bytes) ms is 0 after the first assignment.
Sure, just please describe it all in commit msg. All these questions
"why?" came because of lack of explanation in commit msg.
I guess minimum timeout 100 ms for each transfer is quite high, so maybe
just bump the tolerance to 30 which also would be a minimum timeout.
Best regards,
Krzysztof
>
> >> ---
> >> drivers/spi/spi-s3c64xx.c | 3 ++-
> >> 1 file changed, 2 insertions(+), 1 deletion(-)
> >>
> >> diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
> >> index 27d77600a820..27db1e0f6f32 100644
> >> --- a/drivers/spi/spi-s3c64xx.c
> >> +++ b/drivers/spi/spi-s3c64xx.c
> >> @@ -464,7 +464,8 @@ static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
> >>
> >> /* millisecs to xfer 'len' bytes @ 'cur_speed' */
> >> ms = xfer->len * 8 * 1000 / sdd->cur_speed;
> >> - ms += 10; /* some tolerance */
> >> + ms = (ms * 10) + 30; /* some tolerance */
> >> + ms = max(ms, 100); /* minimum timeout */
> >>
> >> val = msecs_to_jiffies(ms) + 10;
> >> val = wait_for_completion_timeout(&sdd->xfer_completion, val);
> >> --
> >> 2.26.2
> >>
> >
> >
>
> --
> Łukasz Stelmach
> Samsung R&D Institute Poland
> Samsung Electronics
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next prev parent reply other threads:[~2020-08-21 7:10 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20200819123225eucas1p28be1b1920ade0ba8997bc17da97599b6@eucas1p2.samsung.com>
2020-08-19 12:32 ` [PATCH 0/8] Some fixes for spi-s3c64xx Łukasz Stelmach
2020-08-19 12:32 ` Łukasz Stelmach
[not found] ` <CGME20200819123226eucas1p16c9b90330d957344f99f6ee461190085@eucas1p1.samsung.com>
2020-08-19 12:32 ` [PATCH 1/8] spi: spi-s3c64xx: swap s3c64xx_spi_set_cs() and s3c64xx_enable_datapath() Łukasz Stelmach
2020-08-19 12:32 ` Łukasz Stelmach
2020-08-19 12:38 ` Krzysztof Kozlowski
2020-08-19 12:38 ` Krzysztof Kozlowski
[not found] ` <CGME20200819125150eucas1p1965fab59b6e75cf54cac262161c5695b@eucas1p1.samsung.com>
2020-08-19 12:51 ` Lukasz Stelmach
2020-08-19 12:51 ` Lukasz Stelmach
2020-08-19 12:58 ` Krzysztof Kozlowski
2020-08-19 12:58 ` Krzysztof Kozlowski
2020-08-19 13:16 ` Mark Brown
2020-08-19 13:16 ` Mark Brown
[not found] ` <CGME20200819140203eucas1p2818858289f2394b32f3c647e47705cd2@eucas1p2.samsung.com>
2020-08-19 14:01 ` Lukasz Stelmach
2020-08-19 14:01 ` Lukasz Stelmach
2020-08-19 19:12 ` Mark Brown
2020-08-19 19:12 ` Mark Brown
[not found] ` <CGME20200820101251eucas1p237a794cc11f44c709c0ccdfef766702c@eucas1p2.samsung.com>
2020-08-20 10:12 ` Lukasz Stelmach
2020-08-20 10:12 ` Lukasz Stelmach
[not found] ` <CGME20200819123226eucas1p2f4be625abd7ddaac2f09bdf94395346b@eucas1p2.samsung.com>
2020-08-19 12:32 ` [PATCH 2/8] spi: spi-s3s64xx: Add S3C64XX_SPI_QUIRK_CS_AUTO for Exynos3250 Łukasz Stelmach
2020-08-19 12:32 ` Łukasz Stelmach
2020-08-19 12:39 ` Krzysztof Kozlowski
2020-08-19 12:39 ` Krzysztof Kozlowski
[not found] ` <CGME20200819130122eucas1p27e9e84c4399d01409858de6d01e11b52@eucas1p2.samsung.com>
2020-08-19 13:01 ` Lukasz Stelmach
2020-08-19 13:01 ` Lukasz Stelmach
2020-08-19 13:06 ` Krzysztof Kozlowski
2020-08-19 13:06 ` Krzysztof Kozlowski
2020-08-19 19:38 ` Mark Brown
2020-08-19 19:38 ` Mark Brown
[not found] ` <CGME20200820104737eucas1p140e3c575eb692a1de54c5a702951ebfe@eucas1p1.samsung.com>
2020-08-20 10:47 ` Lukasz Stelmach
2020-08-20 10:47 ` Lukasz Stelmach
[not found] ` <CGME20200819123226eucas1p2dc50cd60f71f2155524ec21bf4dcdd74@eucas1p2.samsung.com>
2020-08-19 12:32 ` [PATCH 3/8] spi: spi-s3c64xx: Report more information when errors occur Łukasz Stelmach
2020-08-19 12:32 ` Łukasz Stelmach
2020-08-19 12:43 ` Krzysztof Kozlowski
2020-08-19 12:43 ` Krzysztof Kozlowski
[not found] ` <CGME20200819123227eucas1p1f56cc06dc6c368abf2d3952ba04f37e2@eucas1p1.samsung.com>
2020-08-19 12:32 ` [PATCH 4/8] spi: spi-s3c64xx: Rename S3C64XX_SPI_SLAVE_* to S3C64XX_SPI_CS_* Łukasz Stelmach
2020-08-19 12:32 ` Łukasz Stelmach
2020-08-19 12:44 ` Krzysztof Kozlowski
2020-08-19 12:44 ` Krzysztof Kozlowski
[not found] ` <CGME20200819123227eucas1p11cd47cf281a035ed02d5fc819a0370c1@eucas1p1.samsung.com>
2020-08-19 12:32 ` [PATCH 5/8] spi: spi-s3c64xx: Fix doc comment for struct s3c64xx_spi_driver_data Łukasz Stelmach
2020-08-19 12:32 ` Łukasz Stelmach
2020-08-19 12:37 ` Krzysztof Kozlowski
2020-08-19 12:37 ` Krzysztof Kozlowski
[not found] ` <CGME20200819132540eucas1p1897948a4f4008ab4946120dd4fa5c192@eucas1p1.samsung.com>
2020-08-19 13:25 ` Lukasz Stelmach
2020-08-19 13:25 ` Lukasz Stelmach
[not found] ` <CGME20200819123227eucas1p11ec027714c16d5a66c89c6ef1f7b3604@eucas1p1.samsung.com>
2020-08-19 12:32 ` [PATCH 6/8] spi: spi-s3c64xx: Check return values Łukasz Stelmach
2020-08-19 12:32 ` Łukasz Stelmach
2020-08-19 12:48 ` Krzysztof Kozlowski
2020-08-19 12:48 ` Krzysztof Kozlowski
[not found] ` <CGME20200819154154eucas1p1e88747d2495e6d1074991419504066df@eucas1p1.samsung.com>
2020-08-19 15:41 ` Lukasz Stelmach
2020-08-19 15:41 ` Lukasz Stelmach
2020-08-19 16:13 ` Krzysztof Kozlowski
2020-08-19 16:13 ` Krzysztof Kozlowski
[not found] ` <CGME20200819123228eucas1p19ac7fc04dec52c733ab9c770e91f6ace@eucas1p1.samsung.com>
2020-08-19 12:32 ` [PATCH 7/8] spi: spi-s3c64xx: Increase transfer timeout Łukasz Stelmach
2020-08-19 12:32 ` Łukasz Stelmach
2020-08-19 12:49 ` Krzysztof Kozlowski
2020-08-19 12:49 ` Krzysztof Kozlowski
[not found] ` <CGME20200819133957eucas1p293192baeabb9788ac9148068c1627a57@eucas1p2.samsung.com>
2020-08-19 13:39 ` Lukasz Stelmach
2020-08-19 13:39 ` Lukasz Stelmach
2020-08-21 7:10 ` Krzysztof Kozlowski [this message]
2020-08-21 7:10 ` Krzysztof Kozlowski
[not found] ` <CGME20200819123228eucas1p132d530d17256f887d93ed7792f5b9587@eucas1p1.samsung.com>
2020-08-19 12:32 ` [PATCH 8/8] spi: spi-s3c64xx: Turn on interrupts upon resume Łukasz Stelmach
2020-08-19 12:32 ` Łukasz Stelmach
2020-08-19 12:53 ` Krzysztof Kozlowski
2020-08-19 12:53 ` Krzysztof Kozlowski
[not found] ` <CGME20200819133334eucas1p2080182850c7ba84829e3304a1172afff@eucas1p2.samsung.com>
2020-08-19 13:33 ` Lukasz Stelmach
2020-08-19 13:33 ` Lukasz Stelmach
2020-08-19 12:50 ` [PATCH 0/8] Some fixes for spi-s3c64xx Krzysztof Kozlowski
2020-08-19 12:50 ` Krzysztof Kozlowski
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