diff options
| author | Sascha Hauer <s.hauer@pengutronix.de> | 2022-04-22 09:28:18 +0200 |
|---|---|---|
| committer | Heiko Stuebner <heiko@sntech.de> | 2022-05-03 11:16:48 +0200 |
| commit | 6931f85c29d5a0261219cf8a73773d3165806d84 (patch) | |
| tree | 7d6ef7f632f77b011b24e0f8f7696fe2420412e8 /drivers/clk/rockchip | |
| parent | 7adc1b98bb6e6611bc9122de77737b193b693122 (diff) | |
| download | linux-6931f85c29d5a0261219cf8a73773d3165806d84.tar.bz2 | |
clk: rockchip: Mark hclk_vo as critical on rk3568
Whenever pclk_vo is enabled hclk_vo must be enabled as well. This is
described in the Reference Manual as:
| 2.8.6 NIU Clock gating reliance
|
| A part of niu clocks have a dependence on another niu clock in order to
| sharing the internal bus. When these clocks are in use, another niu
| clock must be opened, and cannot be gated. These clocks and the special
| clock on which they are relied are as following:
|
| Clocks which have dependency The clock which can not be gated
| -----------------------------------------------------------------
| ...
| pclk_vo_niu, hclk_vo_s_niu hclk_vo_niu
| ...
The clock framework doesn't offer a way to enable clock B whenever clock A is
enabled, at least not when B is not an ancestor of A. Workaround this by
marking hclk_vo as critical so it is never disabled. This is suboptimal in
terms of power consumption, but a stop gap solution until the clock framework
has a way to deal with this.
We have this clock tree:
| aclk_vo 2 2 0 300000000 0 0 50000 Y
| aclk_hdcp 0 0 0 300000000 0 0 50000 N
| pclk_vo 2 3 0 75000000 0 0 50000 Y
| pclk_edp_ctrl 0 0 0 75000000 0 0 50000 N
| pclk_dsitx_1 0 0 0 75000000 0 0 50000 N
| pclk_dsitx_0 1 2 0 75000000 0 0 50000 Y
| pclk_hdmi_host 1 2 0 75000000 0 0 50000 Y
| pclk_hdcp 0 0 0 75000000 0 0 50000 N
| hclk_vo 2 5 0 150000000 0 0 50000 Y
| hclk_hdcp 0 0 0 150000000 0 0 50000 N
| hclk_vop 0 2 0 150000000 0 0 50000 N
Without this patch the edp, dsitx, hdmi and hdcp driver would enable their
clocks which then enables pclk_vo, but hclk_vo stays disabled and register
accesses just hang. hclk_vo is enabled by the VOP2 driver, so reproducibility
of this issue depends on the probe order.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Michael Riesch <michael.riesch@wolfvision.net>
Link: https://lore.kernel.org/r/20220422072841.2206452-2-s.hauer@pengutronix.de
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Diffstat (limited to 'drivers/clk/rockchip')
| -rw-r--r-- | drivers/clk/rockchip/clk-rk3568.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/clk/rockchip/clk-rk3568.c b/drivers/clk/rockchip/clk-rk3568.c index 606ae6cd918b..f85902e2590c 100644 --- a/drivers/clk/rockchip/clk-rk3568.c +++ b/drivers/clk/rockchip/clk-rk3568.c @@ -1591,6 +1591,7 @@ static const char *const rk3568_cru_critical_clocks[] __initconst = { "hclk_php", "pclk_php", "hclk_usb", + "hclk_vo", }; static const char *const rk3568_pmucru_critical_clocks[] __initconst = { |