From: Thomas Zimmermann <tzimmermann@suse.de>
To: Icenowy Zheng <icenowy@aosc.io>, Torsten Duwe <duwe@lst.de>
Cc: Jernej Skrabec <jernej.skrabec@siol.net>,
Jonas Karlman <jonas@kwiboo.se>,
Neil Armstrong <narmstrong@baylibre.com>,
linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org,
Vasily Khoruzhick <anarsoul@gmail.com>,
Andrzej Hajda <a.hajda@samsung.com>,
Laurent Pinchart <Laurent.pinchart@ideasonboard.com>,
Maxime Ripard <maxime@cerno.tech>
Subject: Re: [PATCH] drm/bridge: analogix-anx6345: fix set of link bandwidth
Date: Thu, 27 Feb 2020 12:34:13 +0100 [thread overview]
Message-ID: <08f290ef-7dd0-c8b9-0177-3248fb153eca@suse.de> (raw)
In-Reply-To: <07EED5EC-28C6-473D-B672-509F5C770479@aosc.io>
Hi
Am 26.02.20 um 12:02 schrieb Icenowy Zheng:
>
>
> 于 2020年2月26日 GMT+08:00 下午6:58:43, Thomas Zimmermann <tzimmermann@suse.de> 写到:
>> Hi Iceynow,
>>
>> Torsten asked me to merge your patch via drm-misc-next. I'd add the
>> additional cc and fixes tags that Torsten listed. Are you OK with that?
>
> I think this fixes a driver (and a board) available in 5.6.
>
> Maybe it should enter fixes?
Pushed to drm-misc-fixes
Best regards
Thomas
>
>>
>> Best regards
>> Thomas
>>
>> Am 22.02.20 um 03:43 schrieb Icenowy Zheng:
>>>
>>>
>>> 于 2020年2月22日 GMT+08:00 上午1:13:28, Torsten Duwe <duwe@lst.de> 写到:
>>>> On Sat, Feb 22, 2020 at 12:51:27AM +0800, Icenowy Zheng wrote:
>>>>> Current code tries to store the link rate (in bps, which is a big
>>>>> number) in a u8, which surely overflow. Then it's converted back to
>>>>> bandwidth code (which is thus 0) and written to the chip.
>>>>>
>>>>> The code sometimes works because the chip will automatically
>> fallback
>>>> to
>>>>> the lowest possible DP link rate (1.62Gbps) when get the invalid
>>>> value.
>>>>> However, on the eDP panel of Olimex TERES-I, which wants 2.7Gbps
>>>> link,
>>>>> it failed.
>>>>>
>>>>> As we had already read the link bandwidth as bandwidth code in
>>>> earlier
>>>>> code (to check whether it is supported), use it when setting
>>>> bandwidth,
>>>>> instead of converting it to link rate and then converting back.
>>>>>
>>>>> Fixes: e1cff82c1097 ("drm/bridge: fix anx6345 compilation for
>> v5.5")
>>>>> Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
>>>>> ---
>>>>> drivers/gpu/drm/bridge/analogix/analogix-anx6345.c | 3 +--
>>>>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>>>>
>>>>> diff --git a/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c
>>>> b/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c
>>>>> index 56f55c53abfd..2dfa2fd2a23b 100644
>>>>> --- a/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c
>>>>> +++ b/drivers/gpu/drm/bridge/analogix/analogix-anx6345.c
>>>>> @@ -210,8 +210,7 @@ static int anx6345_dp_link_training(struct
>>>> anx6345 *anx6345)
>>>>> if (err)
>>>>> return err;
>>>>>
>>>>> - dpcd[0] = drm_dp_max_link_rate(anx6345->dpcd);
>>>>> - dpcd[0] = drm_dp_link_rate_to_bw_code(dpcd[0]);
>>>>> + dpcd[0] = dp_bw;
>>>>
>>>> Why do you make this assignment and not use dp_bw directly in the
>> call?
>>>
>>> Because the dpcd array is then written as a continous array
>>> back to DPCD.
>>>
>>>>
>>>>> err = regmap_write(anx6345->map[I2C_IDX_DPTX],
>>>>> SP_DP_MAIN_LINK_BW_SET_REG, dpcd[0]);
>>>> ^^^^^^
>>>>> if (err)
>>>>> --
>>>>> 2.24.1
>>>>
>>>> BTW, my version is only a bit more verbose:
>>>>
>>>> https://patchwork.freedesktop.org/patch/354344/
>>>>
>>>> Torsten
>>>
>
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer
_______________________________________________
dri-devel mailing list
dri-devel@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/dri-devel
prev parent reply other threads:[~2020-02-27 11:34 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-21 16:51 [PATCH] drm/bridge: analogix-anx6345: fix set of link bandwidth Icenowy Zheng
2020-02-21 17:13 ` Torsten Duwe
2020-02-22 2:43 ` Icenowy Zheng
2020-02-24 10:44 ` Torsten Duwe
2020-02-26 10:58 ` Thomas Zimmermann
2020-02-26 11:02 ` Icenowy Zheng
2020-02-26 11:59 ` Thomas Zimmermann
2020-02-27 11:34 ` Thomas Zimmermann [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=08f290ef-7dd0-c8b9-0177-3248fb153eca@suse.de \
--to=tzimmermann@suse.de \
--cc=Laurent.pinchart@ideasonboard.com \
--cc=a.hajda@samsung.com \
--cc=anarsoul@gmail.com \
--cc=dri-devel@lists.freedesktop.org \
--cc=duwe@lst.de \
--cc=icenowy@aosc.io \
--cc=jernej.skrabec@siol.net \
--cc=jonas@kwiboo.se \
--cc=linux-kernel@vger.kernel.org \
--cc=maxime@cerno.tech \
--cc=narmstrong@baylibre.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).