Re: [PATCH v2 12/15] phy: qcom-qmp-pcie: fix initialisation reset

From: Dmitry Baryshkov
Date: Wed Oct 19 2022 - 10:18:31 EST


On 19/10/2022 14:35, Johan Hovold wrote:
Add the missing delay after asserting reset. This is specifically needed
for the reset to have any effect on SC8280XP.

The vendor driver uses a 1 ms delay, but that seems a bit excessive.
Instead use a 200 us delay which appears to be more than enough and also
matches the UFS reset delay added by commit 870b1279c7a0 ("scsi:
ufs-qcom: Add reset control support for host controller").

Signed-off-by: Johan Hovold <johan+linaro@xxxxxxxxxx>
---
drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
index 2f4bdef73395..9c8e009033f1 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
@@ -1866,6 +1866,8 @@ static int qmp_pcie_init(struct phy *phy)
goto err_disable_regulators;
}
+ usleep_range(200, 300);
+

If there is a v3, I'd kindly ask to add a comment about vendor using 1ms here.

ret = reset_control_bulk_deassert(cfg->num_resets, qmp->resets);
if (ret) {
dev_err(qmp->dev, "reset deassert failed\n");

--
With best wishes
Dmitry