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 <[email protected]>
---
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;
err = regmap_write(anx6345->map[I2C_IDX_DPTX],
SP_DP_MAIN_LINK_BW_SET_REG, dpcd[0]);
if (err)
--
2.24.1
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 <[email protected]>
> ---
> 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?
> 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
于 2020年2月22日 GMT+08:00 上午1:13:28, Torsten Duwe <[email protected]> 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 <[email protected]>
>> ---
>> 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
--
使用 K-9 Mail 发送自我的Android设备。
On Sat, Feb 22, 2020 at 10:43:02AM +0800, Icenowy Zheng wrote:
>
>
> 于 2020年2月22日 GMT+08:00 上午1:13:28, Torsten Duwe <[email protected]> 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 <[email protected]>
> >> ---
> >> 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.
But the current code never changes this value?
Anyway, as this might change in the future, I support your version;
I want to see this fixed.
Reviewed-by: Torsten Duwe <[email protected]>
Fixes: e1cff82c1097 ("drm/bridge: fix anx6345 compilation for v5.5")
Cc: Maxime Ripard <[email protected]>
Cc: Torsten Duwe <[email protected]>
Cc: Sam Ravnborg <[email protected]>
Cc: Linus Walleij <[email protected]>
Cc: Thomas Zimmermann <[email protected]>
Cc: Icenowy Zheng <[email protected]>
Cc: Stephen Rothwell <[email protected]>
> >
> >> 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
>
> --
> 使用 K-9 Mail 发送自我的Android设备。
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?
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 <[email protected]> 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 <[email protected]>
>>> ---
>>> 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
于 2020年2月26日 GMT+08:00 下午6:58:43, Thomas Zimmermann <[email protected]> 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?
>
>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 <[email protected]> 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 <[email protected]>
>>>> ---
>>>> 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
>>
--
使用 K-9 Mail 发送自我的Android设备。
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 <[email protected]> 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?
I think we can do that. Anything else?
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 <[email protected]> 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 <[email protected]>
>>>>> ---
>>>>> 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
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 <[email protected]> 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 <[email protected]> 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 <[email protected]>
>>>>> ---
>>>>> 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