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

[Rong Chen]

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@xxxxxxxxxxx" <Rong.Chen@xxxxxxxxxxx> 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@xxxxxxxxxxx
> >
> >
> >   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@xxxxxxxxxxxx. 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@xxxxxxxxxxx> wrote:
> >
> >   > From: Rong Chen <rong.chen@xxxxxxxxxxx>
> >   >
> >   > 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@xxxxxxxxxxx>
> >   > ---
> >   >  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);