From: Kishon Vijay Abraham I <[email protected]> Commit 92702df3570e ("ARM: OMAP4: PM: fix PM regression introduced by recent clock cleanup") makes the 'ocp2scp_usb_phy_phy_48m' as optional functional clock causing regression in MUSB. But this 48MHz clock is a mandatory clock for usb phy attached to ocp2scp and hence made as the main clock for ocp2scp.
Cc: Keerthy <[email protected]> Cc: Benoît Cousson <[email protected]> Cc: Paul Walmsley <[email protected]> Signed-off-by: Kishon Vijay Abraham I <[email protected]> [[email protected]: add comment to the hwmod data to try to prevent any future mistakes here] Signed-off-by: Paul Walmsley <[email protected]> --- Nothing further received from Kishon per the request: http://marc.info/?l=linux-omap&m=136554118302342&w=2 Since the deadline for v3.9-rc fixes is quite close, have added the comment myself, and have confirmed that this patch does not cause additional PM regressions on 4460 Panda-ES in the tests here. arch/arm/mach-omap2/omap_hwmod_44xx_data.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c index 9e05765..eaba9dc 100644 --- a/arch/arm/mach-omap2/omap_hwmod_44xx_data.c +++ b/arch/arm/mach-omap2/omap_hwmod_44xx_data.c @@ -2714,16 +2714,22 @@ static struct omap_ocp2scp_dev ocp2scp_dev_attr[] = { { } }; -static struct omap_hwmod_opt_clk ocp2scp_usb_phy_opt_clks[] = { - { .role = "48mhz", .clk = "ocp2scp_usb_phy_phy_48m" }, -}; - /* ocp2scp_usb_phy */ static struct omap_hwmod omap44xx_ocp2scp_usb_phy_hwmod = { .name = "ocp2scp_usb_phy", .class = &omap44xx_ocp2scp_hwmod_class, .clkdm_name = "l3_init_clkdm", - .main_clk = "func_48m_fclk", + /* + * ocp2scp_usb_phy_phy_48m is provided by the OMAP4 PRCM IP + * block as an "optional clock," and normally should never be + * specified as the main_clk for an OMAP IP block. However it + * turns out that this clock is actually the main clock for + * the ocp2scp_usb_phy IP block: + * http://lists.infradead.org/pipermail/linux-arm-kernel/2012-September/119943.html + * So listing ocp2scp_usb_phy_phy_48m as a main_clk here seems + * to be the best workaround. + */ + .main_clk = "ocp2scp_usb_phy_phy_48m", .prcm = { .omap4 = { .clkctrl_offs = OMAP4_CM_L3INIT_USBPHYOCP2SCP_CLKCTRL_OFFSET, @@ -2732,8 +2738,6 @@ static struct omap_hwmod omap44xx_ocp2scp_usb_phy_hwmod = { }, }, .dev_attr = ocp2scp_dev_attr, - .opt_clks = ocp2scp_usb_phy_opt_clks, - .opt_clks_cnt = ARRAY_SIZE(ocp2scp_usb_phy_opt_clks), }; /* -- 1.7.10.4
