Messages in this thread | | | From | Leonard Crestez <> | Subject | Re: [PATCH] ARM: imx: Drop imx_anatop_init() | Date | Thu, 22 Aug 2019 23:26:47 +0000 |
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On 22.08.2019 23:06, Andrey Smirnov wrote: >> On 31.07.2019 21:01, Andrey Smirnov wrote: >>> With commit b5bbe2235361 ("usb: phy: mxs: Disable external charger >>> detect in mxs_phy_hw_init()") in tree all of the necessary charger >>> setup is done by the USB PHY driver which covers all of the affected >>> i.MX6 SoCs. >>> >>> NOTE: Imx_anatop_init() was also called for i.MX7D, but looking at its >>> datasheet it appears to have a different USB PHY IP block, so >>> executing i.MX6 charger disable configuration seems unnecessary. >>> >>> -void __init imx_anatop_init(void) >>> -{ >>> - anatop = syscon_regmap_lookup_by_compatible("fsl,imx6q-anatop"); >>> - if (IS_ERR(anatop)) { >>> - pr_err("%s: failed to find imx6q-anatop regmap!\n", __func__); >>> - return; >>> - } >> >> This patch breaks suspend on imx6 in linux-next because the "anatop" >> regmap is no longer initialized. This was found via bisect but >> no_console_suspend prints a helpful stack anyway: >> >> (regmap_read) from [<c01226e4>] (imx_anatop_enable_weak2p5+0x28/0x70) >> (imx_anatop_enable_weak2p5) from [<c0122744>] >> (imx_anatop_pre_suspend+0x18/0x64) >> (imx_anatop_pre_suspend) from [<c0124434>] (imx6q_pm_enter+0x60/0x16c) >> (imx6q_pm_enter) from [<c018c8a4>] (suspend_devices_and_enter+0x7d4/0xcbc) >> (suspend_devices_and_enter) from [<c018d544>] (pm_suspend+0x7b8/0x904) >> (pm_suspend) from [<c018b1b4>] (state_store+0x68/0xc8) >> > > My bad, completely missed that fact that anatop was a global variable > in imx_anatop_init(). Sorry about that. > >> Minimal fix looks like this: >> >> --- arch/arm/mach-imx/anatop.c >> +++ arch/arm/mach-imx/anatop.c >> @@ -111,6 +111,12 @@ void __init imx_init_revision_from_anatop(void) >> digprog = readl_relaxed(anatop_base + offset); >> iounmap(anatop_base); >> >> + anatop = syscon_regmap_lookup_by_compatible("fsl,imx6q-anatop"); >> + if (IS_ERR(anatop)) { >> + pr_err("failed to find imx6q-anatop regmap!\n"); >> + return; >> + } >> >> Since all SOCs that called imx_anatop_init also call >> imx_init_revision_from_anatop this might be an acceptable solution, >> unless there is some limitation preventing early regmap lookup. >> > > Would making every function that uses anatop explicitly request it via > syscon_regmap_lookup_by_compatible("fsl,imx6q-anatop") be too much of > a code duplication? This way we won't need to worry if > imx_init_revision_from_anatop() was called before any of them are > used.
It's only used from pre_suspend and post_suspend, everything else in arch/arm/mach-imx/anatop.c is static. Doing a lookup every time would be silly, it's fine to let this be global.
I was wondering if maybe imx_init_revision could somehow end up getting called before syscon/regmap core init.
-- Regards, Leonard
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