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

Lean Sheng Tan
2024-03-15T18:46:17Z

+ @Simon

Best Regards,
*Lean Sheng Tan*

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

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On Mon 4. Mar 2024 at 16:39, Lean Sheng Tan <sheng.tan@9elements.com> wrote:

> 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@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@mailbox.org> wrote:
>
>> From: max <cmax@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@mailbox.org>
>> Cc: Peng Fan <peng.fan@nxp.com>
>> Cc: Jaehoon Chung <jh80.chung@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
>>
>>