Re: [PATCH v4 3/8] scsi: ufs: ufs-mediatek: Remove useless mediatek,ufs-boost-crypt property

From: AngeloGioacchino Del Regno
Date: Tue Apr 16 2024 - 03:55:37 EST


Il 16/04/24 09:03, Peter Wang (王信友) ha scritto:
On Mon, 2024-04-15 at 13:00 +0200, AngeloGioacchino Del Regno wrote:
There is no need to have a property that activates the inline crypto
boost feature, as this needs many things: a regulator, three clocks,
and the mediatek,boost-crypt-microvolt property to be set.

If any one of these is missing, the feature won't be activated,
hence, it is useless to have yet one more property to enable that.

While at it, also address another two issues:
1. Give back the return value to the caller and make sure to fail
probing if we get an -EPROBE_DEFER or -ENOMEM; and
2. Free the ufs_mtk_crypt_cfg structure allocated in the crypto
boost function if said functionality could not be enabled because
it's not supported, as that'd be only wasted memory.

Last but not least, move the devm_kzalloc() call for
ufs_mtk_crypt_cfg
to after getting the dvfsrc-vcore regulator and the boost microvolt
property, as if those fail there's no reason to even allocate that.

Fixes: ac8c2459091c ("scsi: ufs-mediatek: Decouple features from
platform bindings")
Signed-off-by: AngeloGioacchino Del Regno <
angelogioacchino.delregno@xxxxxxxxxxxxx>
---
drivers/ufs/host/ufs-mediatek.c | 55 ++++++++++++++++++-------------
--
1 file changed, 30 insertions(+), 25 deletions(-)

diff --git a/drivers/ufs/host/ufs-mediatek.c b/drivers/ufs/host/ufs-
mediatek.c
index 688d85909ad6..47f16e6720f4 100644
--- a/drivers/ufs/host/ufs-mediatek.c
+++ b/drivers/ufs/host/ufs-mediatek.c
@@ -575,51 +575,55 @@ static int ufs_mtk_init_host_clk(struct ufs_hba
*hba, const char *name,
return ret;
}
-static void ufs_mtk_init_boost_crypt(struct ufs_hba *hba)
+static int ufs_mtk_init_boost_crypt(struct ufs_hba *hba)
{
struct ufs_mtk_host *host = ufshcd_get_variant(hba);
struct ufs_mtk_crypt_cfg *cfg;
struct device *dev = hba->dev;
struct regulator *reg;
u32 volt;
-
- host->crypt = devm_kzalloc(dev, sizeof(*(host->crypt)),
- GFP_KERNEL);
- if (!host->crypt)
- goto disable_caps;
+ int ret;
reg = devm_regulator_get_optional(dev, "dvfsrc-vcore");
if (IS_ERR(reg)) {
- dev_info(dev, "failed to get dvfsrc-vcore: %ld",
- PTR_ERR(reg));
- goto disable_caps;
+ ret = PTR_ERR(reg);
+ if (ret == -EPROBE_DEFER)
+ return ret;
+
+ return 0;
}
- if (of_property_read_u32(dev->of_node, "mediatek,boost-crypt-
microvolt",
- &volt)) {
+ ret = of_property_read_u32(dev->of_node, "mediatek,boost-crypt-
microvolt", &volt);
+ if (ret) {
dev_info(dev, "failed to get mediatek,boost-crypt-
microvolt");
- goto disable_caps;
+ return 0;
}
+ host->crypt = devm_kzalloc(dev, sizeof(*host->crypt),
GFP_KERNEL);
+ if (!host->crypt)
+ return -ENOMEM;
+


Hi Angelo,

If retrun -ENOMEN, host will init fail.
But previous is skip boost crypt feature only.
It change the driver behavior.


This is fully intentional: if a platform supports boost-crypt, this means that the
feature *MUST* be enabled, and must *not* be disabled if a memory allocation fails,
as that is relative to available pages at boot, and not to SoC feature support.

Keep in mind that the allocation was moved to *after* checking if such platform
does indeed support the boost-crypt feature, and it is critical to FAIL probing
if there was no memory to allocate the host->crypt structure.




cfg = host->crypt;
- if (ufs_mtk_init_host_clk(hba, "crypt_mux",
- &cfg->clk_crypt_mux))
- goto disable_caps;
+ ret = ufs_mtk_init_host_clk(hba, "crypt_mux", &cfg-
clk_crypt_mux);
+ if (ret)
+ goto out;
- if (ufs_mtk_init_host_clk(hba, "crypt_lp",
- &cfg->clk_crypt_lp))
- goto disable_caps;
+ ret = ufs_mtk_init_host_clk(hba, "crypt_lp", &cfg-
clk_crypt_lp);
+ if (ret)
+ goto out;
- if (ufs_mtk_init_host_clk(hba, "crypt_perf",
- &cfg->clk_crypt_perf))
- goto disable_caps;
+ ret = ufs_mtk_init_host_clk(hba, "crypt_perf", &cfg-
clk_crypt_perf);
+ if (ret)
+ goto out;
cfg->reg_vcore = reg;
cfg->vcore_volt = volt;
host->caps |= UFS_MTK_CAP_BOOST_CRYPT_ENGINE;
-disable_caps:
- return;
+out:
+ if (ret)
+ devm_kfree(dev, host->crypt);
+ return 0;
}
static int ufs_mtk_init_va09_pwr_ctrl(struct ufs_hba *hba)
@@ -648,8 +652,9 @@ static int ufs_mtk_init_host_caps(struct ufs_hba
*hba)
struct device_node *np = hba->dev->of_node;
int ret;
- if (of_property_read_bool(np, "mediatek,ufs-boost-crypt"))
- ufs_mtk_init_boost_crypt(hba);
+ ret = ufs_mtk_init_boost_crypt(hba);
+ if (ret)
+ return ret;

Most ufs-mediatek platform dosen't need "mediatek,ufs-boost-crypt"
Remove this property will casue most platform try error and add init
latency.


Yes this causes -> less than half of a millisecond <- of additional boot time
if the dvfsrc-supply is present but boost-microvolt is not.

I really don't see the problem with that :-)

Regards,
Angelo

Thanks.
Peter



ret = ufs_mtk_init_va09_pwr_ctrl(hba);
if (ret)