[PATCH] spi: spi-qpic-snand: document the limited bit error reporting capability

[PATCH] spi: spi-qpic-snand: document the limited bit error reporting capability

[Gabor Juhos]

The QPIC hardware is not capable of reporting the exact number of the
corrected bit errors, it only reports the number of the corrected bytes.

Document this behaviour in the code, and also issue a warning message
to inform the user about it.

No functional changes.

Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
---
 drivers/spi/spi-qpic-snand.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/spi/spi-qpic-snand.c b/drivers/spi/spi-qpic-snand.c
index fd129650434f0129e24d3bdac7e7c4d5542627e6..c2f5ef899f6a60ad98b9d754b7cac1832d0500eb 100644
--- a/drivers/spi/spi-qpic-snand.c
+++ b/drivers/spi/spi-qpic-snand.c
@@ -639,6 +639,20 @@ static int qcom_spi_check_error(struct qcom_nand_controller *snandc)
 			unsigned int stat;
 
 			stat = buffer & BS_CORRECTABLE_ERR_MSK;
+
+			/*
+			 * The exact number of the corrected bits is
+			 * unknown because the hardware only reports the
+			 * number of the corrected bytes.
+			 *
+			 * Since we have no better solution at the moment,
+			 * report that value as the number of bit errors
+			 * despite that it is inaccurate in most cases.
+			 */
+			if (stat && stat != ecc_cfg->strength)
+				dev_warn_once(snandc->dev,
+					      "Warning: due to hw limitation, the reported number of the corrected bits may be inaccurate\n");
+
 			snandc->qspi->ecc_stats.corrected += stat;
 			max_bitflips = max(max_bitflips, stat);
 		}

---
base-commit: b00d6864a4c948529dc6ddd2df76bf175bf27c63
change-id: 20250527-qpic-snand-limited-biterr-caps-a198b01c1f0a

Best regards,
-- 
Gabor Juhos <j4g8y7@gmail.com>

Re: [PATCH] spi: spi-qpic-snand: document the limited bit error reporting capability

[Mark Brown]

On Tue, 27 May 2025 13:08:16 +0200, Gabor Juhos wrote:
> The QPIC hardware is not capable of reporting the exact number of the
> corrected bit errors, it only reports the number of the corrected bytes.
> 
> Document this behaviour in the code, and also issue a warning message
> to inform the user about it.
> 
> No functional changes.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: spi-qpic-snand: document the limited bit error reporting capability
      commit: 57cf46cd1fe351846e1b065ca9546eef66675ecd

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

Re: [PATCH] spi: spi-qpic-snand: document the limited bit error reporting capability

[Miquel Raynal]

Hi Gabor,

On 27/05/2025 at 13:08:16 +02, Gabor Juhos <j4g8y7@gmail.com> wrote:

> The QPIC hardware is not capable of reporting the exact number of the
> corrected bit errors, it only reports the number of the corrected bytes.
>
> Document this behaviour in the code, and also issue a warning message
> to inform the user about it.
>
> No functional changes.
>
> Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>

This change no longer applies on v6.16-rc1, can you please rebase and
resend?

Thanks,
Miquèl

Re: [PATCH] spi: spi-qpic-snand: document the limited bit error reporting capability

[Gabor Juhos]

Hi Miquel,

> On 27/05/2025 at 13:08:16 +02, Gabor Juhos <j4g8y7@gmail.com> wrote:
> 
>> The QPIC hardware is not capable of reporting the exact number of the
>> corrected bit errors, it only reports the number of the corrected bytes.
>>
>> Document this behaviour in the code, and also issue a warning message
>> to inform the user about it.
>>
>> No functional changes.
>>
>> Signed-off-by: Gabor Juhos <j4g8y7@gmail.com>
> 
> This change no longer applies on v6.16-rc1, can you please rebase and
> resend?

It is not needed since v6.16-rc1 contains the change already (57cf46cd1fe3).

Regars,
Gabor