2022-02-16 13:24:11

by Rong Chen

[permalink] [raw]
Subject: [PATCH v2] mmc: meson: Fix usage of meson_mmc_post_req()

Currently meson_mmc_post_req() is called in meson_mmc_request() right
after meson_mmc_start_cmd(). This could lead to DMA unmapping before the request
is actually finished.

To fix, don't call meson_mmc_post_req() until meson_mmc_request_done().

Signed-off-by: Rong Chen <[email protected]>
---
drivers/mmc/host/meson-gx-mmc.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
index 8f36536cb1b6..58ab9d90bc8b 100644
--- a/drivers/mmc/host/meson-gx-mmc.c
+++ b/drivers/mmc/host/meson-gx-mmc.c
@@ -173,6 +173,8 @@ struct meson_host {
int irq;

bool vqmmc_enabled;
+ bool needs_pre_post_req;
+
};

#define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
@@ -663,6 +665,8 @@ static void meson_mmc_request_done(struct mmc_host *mmc,
struct meson_host *host = mmc_priv(mmc);

host->cmd = NULL;
+ if (host->needs_pre_post_req)
+ meson_mmc_post_req(mmc, mrq, 0);
mmc_request_done(host->mmc, mrq);
}

@@ -880,7 +884,7 @@ static int meson_mmc_validate_dram_access(struct mmc_host *mmc, struct mmc_data
static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
{
struct meson_host *host = mmc_priv(mmc);
- bool needs_pre_post_req = mrq->data &&
+ host->needs_pre_post_req = mrq->data &&
!(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);

/*
@@ -896,22 +900,19 @@ static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
}
}

- if (needs_pre_post_req) {
+ if (host->needs_pre_post_req) {
meson_mmc_get_transfer_mode(mmc, mrq);
if (!meson_mmc_desc_chain_mode(mrq->data))
- needs_pre_post_req = false;
+ host->needs_pre_post_req = false;
}

- if (needs_pre_post_req)
+ if (host->needs_pre_post_req)
meson_mmc_pre_req(mmc, mrq);

/* Stop execution */
writel(0, host->regs + SD_EMMC_START);

meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
-
- if (needs_pre_post_req)
- meson_mmc_post_req(mmc, mrq, 0);
}

static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
--
2.25.1


2022-02-19 07:35:33

by Kevin Hilman

[permalink] [raw]
Subject: Re: [PATCH v2] mmc: meson: Fix usage of meson_mmc_post_req()

Rong Chen <[email protected]> writes:

> Currently meson_mmc_post_req() is called in meson_mmc_request() right
> after meson_mmc_start_cmd(). This could lead to DMA unmapping before the request
> is actually finished.
>
> To fix, don't call meson_mmc_post_req() until meson_mmc_request_done().
>
> Signed-off-by: Rong Chen <[email protected]>

Reviewed-by: Kevin Hilman <[email protected]>

2022-02-28 18:10:18

by Ulf Hansson

[permalink] [raw]
Subject: Re: [PATCH v2] mmc: meson: Fix usage of meson_mmc_post_req()

+ Hainer

On Wed, 16 Feb 2022 at 13:42, Rong Chen <[email protected]> wrote:
>
> Currently meson_mmc_post_req() is called in meson_mmc_request() right
> after meson_mmc_start_cmd(). This could lead to DMA unmapping before the request
> is actually finished.
>
> To fix, don't call meson_mmc_post_req() until meson_mmc_request_done().
>
> Signed-off-by: Rong Chen <[email protected]>

We should probably add a fixes tag to this, right?
Fixes: 79ed05e329c3 ("mmc: meson-gx: add support for descriptor chain mode")

Moreover, you want this tagged for stable kernels too, right?

I have applied it for fixes and added the above tags, please tell if
you want me to change it.

Kind regards
Uffe


> ---
> drivers/mmc/host/meson-gx-mmc.c | 15 ++++++++-------
> 1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c
> index 8f36536cb1b6..58ab9d90bc8b 100644
> --- a/drivers/mmc/host/meson-gx-mmc.c
> +++ b/drivers/mmc/host/meson-gx-mmc.c
> @@ -173,6 +173,8 @@ struct meson_host {
> int irq;
>
> bool vqmmc_enabled;
> + bool needs_pre_post_req;
> +
> };
>
> #define CMD_CFG_LENGTH_MASK GENMASK(8, 0)
> @@ -663,6 +665,8 @@ static void meson_mmc_request_done(struct mmc_host *mmc,
> struct meson_host *host = mmc_priv(mmc);
>
> host->cmd = NULL;
> + if (host->needs_pre_post_req)
> + meson_mmc_post_req(mmc, mrq, 0);
> mmc_request_done(host->mmc, mrq);
> }
>
> @@ -880,7 +884,7 @@ static int meson_mmc_validate_dram_access(struct mmc_host *mmc, struct mmc_data
> static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
> {
> struct meson_host *host = mmc_priv(mmc);
> - bool needs_pre_post_req = mrq->data &&
> + host->needs_pre_post_req = mrq->data &&
> !(mrq->data->host_cookie & SD_EMMC_PRE_REQ_DONE);
>
> /*
> @@ -896,22 +900,19 @@ static void meson_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
> }
> }
>
> - if (needs_pre_post_req) {
> + if (host->needs_pre_post_req) {
> meson_mmc_get_transfer_mode(mmc, mrq);
> if (!meson_mmc_desc_chain_mode(mrq->data))
> - needs_pre_post_req = false;
> + host->needs_pre_post_req = false;
> }
>
> - if (needs_pre_post_req)
> + if (host->needs_pre_post_req)
> meson_mmc_pre_req(mmc, mrq);
>
> /* Stop execution */
> writel(0, host->regs + SD_EMMC_START);
>
> meson_mmc_start_cmd(mmc, mrq->sbc ?: mrq->cmd);
> -
> - if (needs_pre_post_req)
> - meson_mmc_post_req(mmc, mrq, 0);
> }
>
> static void meson_mmc_read_resp(struct mmc_host *mmc, struct mmc_command *cmd)
> --
> 2.25.1
>