Hi
> -----Original Message-----
> From: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
> Sent: Wednesday, July 26, 2023 1:30 PM
> To: Horia Geanta <horia.geanta@xxxxxxx>; Pankaj Gupta
> <pankaj.gupta@xxxxxxx>; Gaurav Jain <gaurav.jain@xxxxxxx>; Herbert Xu
> <herbert@xxxxxxxxxxxxxxxxxxx>; David S. Miller <davem@xxxxxxxxxxxxx>
> Cc: linux-crypto@xxxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx
> Subject: [EXT] [PATCH] crypto: caam/jr - Convert to platform remove callback
> returning void
>
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>
> The .remove() callback for a platform driver returns an int which makes many
> driver authors wrongly assume it's possible to do error handling by returning an
> error code. However the value returned is (mostly) ignored and this typically
> results in resource leaks. To improve here there is a quest to make the remove
> callback return void. In the first step of this quest all drivers are converted
> to .remove_new() which already returns void.
>
> The driver adapted here suffers from this wrong assumption. Returning -EBUSY
> if there are still users results in resource leaks and probably a crash. Also further
> down passing the error code of caam_jr_shutdown() to the caller only results in
> another error message and has no further consequences compared to returning
> zero.
>
> Still convert the driver to return no value in the remove callback. This also allows
> to drop caam_jr_platform_shutdown() as the only function called by it now has
> the same prototype.
>
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxxxx>
> ---
> Hello,
>
> note that the problems described above and in the extended comment isn't
> introduced by this patch. It's as old as
> 313ea293e9c4d1eabcaddd2c0800f083b03c2a2e at least.
>
> Also orthogonal to this patch I wonder about the use of a shutdown callback.
> What makes this driver special to require extra handling at shutdown time?
>
> Best regards
> Uwe
>
> drivers/crypto/caam/jr.c | 22 +++++++++-------------
> 1 file changed, 9 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/crypto/caam/jr.c b/drivers/crypto/caam/jr.c index
> 96dea5304d22..66b1eb3eb4a4 100644
> --- a/drivers/crypto/caam/jr.c
> +++ b/drivers/crypto/caam/jr.c
> @@ -162,7 +162,7 @@ static int caam_jr_shutdown(struct device *dev)
> return ret;
> }
>
> -static int caam_jr_remove(struct platform_device *pdev)
> +static void caam_jr_remove(struct platform_device *pdev)
> {
> int ret;
> struct device *jrdev;
> @@ -175,11 +175,14 @@ static int caam_jr_remove(struct platform_device
> *pdev)
> caam_rng_exit(jrdev->parent);
>
> /*
> - * Return EBUSY if job ring already allocated.
> + * If a job ring is still allocated there is trouble ahead. Once
> + * caam_jr_remove() returned, jrpriv will be freed and the registers
> + * will get unmapped. So any user of such a job ring will probably
> + * crash.
> */
> if (atomic_read(&jrpriv->tfm_count)) {
> - dev_err(jrdev, "Device is busy\n");
> - return -EBUSY;
> + dev_warn(jrdev, "Device is busy, fasten your seat belts, a crash is
> ahead.\n");
Changes are ok. Can you improve the error message or keep it same.
Regards
Gaurav
> + return;
> }
>
> /* Unregister JR-based RNG & crypto algorithms */ @@ -194,13 +197,6
> @@ static int caam_jr_remove(struct platform_device *pdev)
> ret = caam_jr_shutdown(jrdev);
> if (ret)
> dev_err(jrdev, "Failed to shut down job ring\n");
> -
> - return ret;
> -}
> -
> -static void caam_jr_platform_shutdown(struct platform_device *pdev) -{
> - caam_jr_remove(pdev);
> }
>
> /* Main per-ring interrupt handler */
> @@ -657,8 +653,8 @@ static struct platform_driver caam_jr_driver = {
> .of_match_table = caam_jr_match,
> },
> .probe = caam_jr_probe,
> - .remove = caam_jr_remove,
> - .shutdown = caam_jr_platform_shutdown,
> + .remove_new = caam_jr_remove,
> + .shutdown = caam_jr_remove,
> };
>
> static int __init jr_driver_init(void)
>
> base-commit: dd105461ad15ea930d88aec1e4fcfc1f3186da43
> --
> 2.39.2
