Messages in this thread | | | From | Kevin Hilman <> | Subject | Re: [PATCH] mmc: meson: Fix usage of meson_mmc_post_req() | Date | Mon, 24 Jan 2022 14:05:17 -0800 |
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Hello Rong,
First, thank you finding the issue and for submitting a fix!
Rong Chen <rong.chen@amlogic.com> writes:
> To ensure the DMA moves data correctly from memory to > peripherals, DMA unmapping when the MMC request done > with calls meson_mmc_post_req(). > > Signed-off-by: Rong Chen <rong.chen@amlogic.com>
The patch looks correct, but I think I think the changelog could be improved. If I understand the code correctly, I think what you're doing is:
""" Currently meson_mmc_post_req() is called in meson_mmc_request() right after _start_cmd(). This could lead to DMA unmapping before the request is actually finished.
To fix, ton't call meson_mmc_post_req() until _request_done(). """
Kevin
> --- > drivers/mmc/host/meson-gx-mmc.c | 14 +++++++------- > 1 file changed, 7 insertions(+), 7 deletions(-) > > diff --git a/drivers/mmc/host/meson-gx-mmc.c b/drivers/mmc/host/meson-gx-mmc.c > index 8f36536cb1b6..6a9554ae4b1c 100644 > --- a/drivers/mmc/host/meson-gx-mmc.c > +++ b/drivers/mmc/host/meson-gx-mmc.c > @@ -173,6 +173,7 @@ struct meson_host { > int irq; > > bool vqmmc_enabled; > + bool needs_pre_post_req; > }; > > #define CMD_CFG_LENGTH_MASK GENMASK(8, 0) > @@ -663,6 +664,8 @@ 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 +883,7 @@ 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 +899,19 @@ 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) > > base-commit: 356f3f2c5756bbb67a515760966a40fc7043cdda > -- > 2.25.1
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