[PATCH] mmc: arm_pl180: Limit data transfer to U16_MAX

[Lean Sheng Tan]

Quick reminder:
Can anyone help to review this?
Thanks!

Best Regards,
*Lean Sheng Tan*



9elements GmbH, Kortumstraße 19-21, 44787 Bochum, Germany
Email: sheng.tan at 9elements.com
Phone: *+49 234 68 94 188 <+492346894188>*
Mobile: *+49 176 76 113842 <+4917676113842>*

Registered office: Bochum
Commercial register: Amtsgericht Bochum, HRB 17519
Management: Sebastian German, Eray Bazaar

Data protection information according to Art. 13 GDPR
<https://9elements.com/privacy>


On Tue, 27 Feb 2024 at 22:02, <cmax at mailbox.org> wrote:

> From: max <cmax at mailbox.org>
>
> Currently fetching files bigger that cause a data transfer greater than
> U16_MAX fails.
>
> The reason is that the specification defines the datalength register
> as a 16 bit wide register, but in u-boot it is used as if it is an
> 32 bit register. Therefore values greater than U16_MAX cause an
> infinite loop inside u-boot. U-boot expects to get more data from
> interface/hardware then it will ever get and therefore inifintely waits
> for more data that will never come.
>
> Signed-off-by: max <cmax at mailbox.org>
> Cc: Peng Fan <peng.fan at nxp.com>
> Cc: Jaehoon Chung <jh80.chung at samsung.com>
> ---
>  drivers/mmc/arm_pl180_mmci.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)
>
> diff --git a/drivers/mmc/arm_pl180_mmci.c b/drivers/mmc/arm_pl180_mmci.c
> index 5cf5502ed5..af2f9a5a84 100644
> --- a/drivers/mmc/arm_pl180_mmci.c
> +++ b/drivers/mmc/arm_pl180_mmci.c
> @@ -231,6 +231,7 @@ static int do_data_transfer(struct mmc *dev,
>         u32 blksz = 0;
>         u32 data_ctrl = 0;
>         u32 data_len = (u32) (data->blocks * data->blocksize);
> +       assert(data_len < U16_MAX); // should be ensured by
> arm_pl180_get_b_max
>
>         if (!host->version2) {
>                 blksz = (ffs(data->blocksize) - 1);
> @@ -358,6 +359,14 @@ static int  host_set_ios(struct mmc *dev)
>         return 0;
>  }
>
> +static int arm_pl180_get_b_max(struct udevice *dev, void *dst, lbaint_t
> blkcnt)
> +{
> +       struct mmc_uclass_priv *upriv = dev_get_uclass_priv(dev);
> +       struct mmc *mmc = upriv->mmc;
> +
> +       return U16_MAX / mmc->read_bl_len;
> +}
> +
>  #ifndef CONFIG_DM_MMC
>  /* MMC uses open drain drivers in the enumeration phase */
>  static int mmc_host_reset(struct mmc *dev)
> @@ -373,6 +382,7 @@ static const struct mmc_ops arm_pl180_mmci_ops = {
>         .send_cmd = host_request,
>         .set_ios = host_set_ios,
>         .init = mmc_host_reset,
> +       .get_b_max = arm_pl180_get_b_max,
>  };
>
>  /*
> @@ -531,6 +541,7 @@ static const struct dm_mmc_ops arm_pl180_dm_mmc_ops = {
>         .send_cmd = dm_host_request,
>         .set_ios = dm_host_set_ios,
>         .get_cd = dm_mmc_getcd,
> +       .get_b_max = arm_pl180_get_b_max,
>  };
>
>  static int arm_pl180_mmc_of_to_plat(struct udevice *dev)
> --
> 2.43.0
>
>