Re: [PATCH] mmc: meson-gx: Remove setting of CMD_CFG_ERROR

[Rong Chen <Rong.Chen@amlogic.com>]

Hi Jerome,

For the t7 and older SoC families, the CMD_CFG_ERROR has no effect.
Starting from SoC family C3, setting this bit without SG LINK data address 
will cause the controller to generate an IRQ and stop working.

在 2023/9/27 17:30, Jerome Brunet 写道:
> [ EXTERNAL EMAIL ]
>
> On Wed 27 Sep 2023 at 16:51, "Rong.Chen@amlogic.com" <Rong.Chen@amlogic.com> wrote:
>
>> Hi Jerome,
>>
>> Socs containing previous controllers are gxl, gxm, gxbb，g12b，g12a，sm1，axg, a1，s4 and t7.
> That is mostly all the SoC we know of in mainline ... This why the way
> you explained is confusing.
>
> And below, you say 'on latest controllers', okay but which ones ?
>
>> The bit CMD_CFG_ERROR is used for selecting SG LINK of data address on latest controllers，but
>> data address don't use SG LINK at present，so it will cause an IRQ and stop working on latest controllers.
>> Therefore, remove this setting.
> Not totally sure what SG LINK but okay.
>
> While the change itself is fine you really need reformulate the description.
> Based on your explanation, something like:
> ---
> For the t7 and older SoC families, the CMD_CFG_ERROR has no effect.
> Starting from SoC family XYZ, it will select SG LINK on error but this
> is causing a problem with the data address ... blablabla
> ---
>
> Please expand a bit on this, try to make it clearer.
> Also, please insert the proper fixes tag
>
> Last, make sure tp reply with plain text emails, otherwise lists will
> drop your reply and please do not top post.
>
> Thx
>
>> Thanks.
>> -------------------------------------------------------------------------------------------------------------------------
>> Rong.Chen@amlogic.com
>>
>>
>>   From: Jerome Brunet
>>   Date: 2023-09-27 15:43
>>   To: Rong.Chen; Ulf Hansson; Neil Armstrong; Kevin Hilman; Martin Blumenstingl
>>   CC: linux-mmc; linux-arm-kernel; linux-amlogic; linux-kernel
>>   Subject: Re: [PATCH] mmc: meson-gx: Remove setting of CMD_CFG_ERROR
>>   [You don't often get email from jbrunet@baylibre.com. Learn why this is important at
>>   https://aka.ms/LearnAboutSenderIdentification ]
>>
>>   [ EXTERNAL EMAIL ]
>>
>>   s
>>   On Wed 27 Sep 2023 at 15:25, "Rong.Chen" <Rong.Chen@amlogic.com> wrote:
>>
>>   > From: Rong Chen <rong.chen@amlogic.com>
>>   >
>>   > Setting bit CMD_CFG_ERROR has non effects on previous controllers.
>>
>>   Which previous controllers ? v2, v3 ? Can you list the SoCs please ?
>>
>>   > However, it will cause an IRQ and stop working on latest controllers,
>>
>>   Isn't it desirable to stop on error ? seems like a sane thing to do.
>>
>>   > This bit is used for selecting SG LINK of data address.
>>   > Don't set the bit CMD_CFG_ERROR anymore to resolve this issuse.
>>
>>   I'm not sure I understand the actual issue being resolved.
>>   Could you provide more details please ?
>>
>>   >
>>   > Therefore, remove this setting.
>>   >
>>   > Signed-off-by: Rong Chen <rong.chen@amlogic.com>
>>   > ---
>>   >  drivers/mmc/host/meson-gx-mmc.c | 1 -
>>   >  1 file changed, 1 deletion(-)
>>   >
>>   > diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
>>   > index 9837dab096e6..c7c067b9415a 100644
>>   > --- a/drivers/mmc/host/meson-gx-mmc.c
>>   > +++ b/drivers/mmc/host/meson-gx-mmc.c
>>   > @@ -801,7 +801,6 @@ static void meson_mmc_start_cmd(struct mmc_host *mmc, struct mmc_command *cmd)
>>   >
>>   >       cmd_cfg |= FIELD_PREP(CMD_CFG_CMD_INDEX_MASK, cmd->opcode);
>>   >       cmd_cfg |= CMD_CFG_OWNER;  /* owned by CPU */
>>   > -     cmd_cfg |= CMD_CFG_ERROR; /* stop in case of error */
>>   >
>>   >       meson_mmc_set_response_bits(cmd, &cmd_cfg);