Re: [PATCH v3 5/6] drm: atmel-hlcdc: prefer a lower pixel-clock than requested

From: <Claudiu.Beznea@microchip.com>
To: <sam@ravnborg.org>
Cc: <alexandre.belloni@bootlin.com>, <airlied@linux.ie>,
	<Nicolas.Ferre@microchip.com>, <dri-devel@lists.freedesktop.org>,
	<linux-kernel@vger.kernel.org>, <boris.brezillon@bootlin.com>,
	<lee.jones@linaro.org>, <peda@axentia.se>,
	<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v3 5/6] drm: atmel-hlcdc: prefer a lower pixel-clock than requested
Date: Mon, 6 Jan 2020 09:25:40 +0000	[thread overview]
Message-ID: <4f8603b2-9ae6-97bf-73c0-1b204595dce1@microchip.com> (raw)
In-Reply-To: <20200104171205.GA8724@ravnborg.org>

On 04.01.2020 19:12, Sam Ravnborg wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> Hi Claudiu
> 
> On Thu, Jan 02, 2020 at 10:08:48AM +0100, Sam Ravnborg wrote:
>> On Wed, Dec 18, 2019 at 02:28:28PM +0200, Claudiu Beznea wrote:
>>> From: Peter Rosin <peda@axentia.se>
>>>
>>> The intention was to only select a higher pixel-clock rate than the
>>> requested, if a slight overclocking would result in a rate significantly
>>> closer to the requested rate than if the conservative lower pixel-clock
>>> rate is selected. The fixed patch has the logic the other way around and
>>> actually prefers the higher frequency. Fix that.
>>>
>>> Fixes: f6f7ad323461 ("drm/atmel-hlcdc: allow selecting a higher pixel-clock than requested")
>> The id is wrong here - the right one is: 9946a3a9dbedaaacef8b7e94f6ac144f1daaf1de
>> The wrong id above was used before - so I think it is a copy'n'paste
>> thing.
>>
>> Hint: try "dim fixes 9946a3a9dbedaaacef8b7e94f6ac144f1daaf1de"
>>
>> If I get a quick response from Lee I can fix it up while applying.
>>
>>       Sam
>>
>>> Reported-by: Claudiu Beznea <claudiu.beznea@microchip.com>
>>> Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
>>> Signed-off-by: Peter Rosin <peda@axentia.se>
> 
> One other detail.
> The patch has passed through your hands, so you have to add your s-o-b
> to document this.
> The chain of s-o-b shall document the path the patch has taken towards
> the kernel.
> 
> In this case:
> Peter => Claudiu => Sam => Applied.
> 
> Please resend or reply where you say OK that I add your s-o-b.

Sure! Please add my Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>

Thank you, Sam!

> 
> PS. And happy new year!
> 
>         Sam
> 
> 
>>> ---
>>>  drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 4 ++--
>>>  1 file changed, 2 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
>>> index 721fa88bf71d..10985134ce0b 100644
>>> --- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
>>> +++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
>>> @@ -121,8 +121,8 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
>>>             int div_low = prate / mode_rate;
>>>
>>>             if (div_low >= 2 &&
>>> -               ((prate / div_low - mode_rate) <
>>> -                10 * (mode_rate - prate / div)))
>>> +               (10 * (prate / div_low - mode_rate) <
>>> +                (mode_rate - prate / div)))
>>>                     /*
>>>                      * At least 10 times better when using a higher
>>>                      * frequency than requested, instead of a lower.
>>> --
>>> 2.7.4
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> 