On Mon, Oct 18, 2021 at 01:19:42AM +0900, Tsuchiya Yuto wrote:
> 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@xxxxxxxxx>
> ---
> 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 */
P-Unit
> 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
>
>
--
With Best Regards,
Andy Shevchenko
