[PATCH 02/17] media: atomisp: pci: fix punit_ddr_dvfs_enable() argument for mrfld_power up case

Tsuchiya Yuto
2021-10-17T16:20:51Z

When comparing with intel-aero atomisp [1], it looks like
punit_ddr_dvfs_enable() should take `false` as an argument on mrfld_power
up case.

Code from the intel-aero kernel [1]:

int atomisp_mrfld_power_down(struct atomisp_device *isp)
{
[...]
/*WA:Enable DVFS*/
if (IS_CHT)
punit_ddr_dvfs_enable(true);

int atomisp_mrfld_power_up(struct atomisp_device *isp)
{
[...]
/*WA for PUNIT, if DVFS enabled, ISP timeout observed*/
if (IS_CHT)
punit_ddr_dvfs_enable(false);

This patch fixes the inverted argument as per the intel-aero code, as
well as its comment. While here, fix space issues for comments in
atomisp_mrfld_power().

Note that it does not seem to be possible to unify the up/down cases for
punit_ddr_dvfs_enable(), i.e., we can't do something like the following:

if (IS_CHT)
punit_ddr_dvfs_enable(!enable);

because according to the intel-aero code [1], the DVFS is disabled
before "writing 0x0 to ISPSSPM0 bit[1:0]" and the DVFS is enabled after
"writing 0x3 to ISPSSPM0 bit[1:0]".

[1] https://github.com/intel-aero/linux-kernel/blob/a1b673258feb915268377275130c5c5df0eafc82/drivers/media/pci/atomisp/atomisp_driver/atomisp_v4l2.c#L431-L514

Fixes: 0f441fd70b1e ("media: atomisp: simplify the power down/up code")
Signed-off-by: Tsuchiya Yuto <kitakar@gmail.com>
---
drivers/staging/media/atomisp/pci/atomisp_v4l2.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/media/atomisp/pci/atomisp_v4l2.c b/drivers/staging/media/atomisp/pci/atomisp_v4l2.c
index 0511c454e769..f5362554638e 100644
--- a/drivers/staging/media/atomisp/pci/atomisp_v4l2.c
+++ b/drivers/staging/media/atomisp/pci/atomisp_v4l2.c
@@ -711,15 +711,15 @@ static int atomisp_mrfld_power(struct atomisp_device *isp, bool enable)

dev_dbg(isp->dev, "IUNIT power-%s.\n", enable ? "on" : "off");

- /*WA:Enable DVFS*/
+ /* WA for PUNIT, if DVFS enabled, ISP timeout observed */
if (IS_CHT && enable)
- punit_ddr_dvfs_enable(true);
+ punit_ddr_dvfs_enable(false);

/*
* FIXME:WA for ECS28A, with this sleep, CTS
* android.hardware.camera2.cts.CameraDeviceTest#testCameraDeviceAbort
* PASS, no impact on other platforms
- */
+ */
if (IS_BYT && enable)
msleep(10);

@@ -727,7 +727,7 @@ static int atomisp_mrfld_power(struct atomisp_device *isp, bool enable)
iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, MRFLD_ISPSSPM0,
val, MRFLD_ISPSSPM0_ISPSSC_MASK);

- /*WA:Enable DVFS*/
+ /* WA:Enable DVFS */
if (IS_CHT && !enable)
punit_ddr_dvfs_enable(true);

--
2.33.1