Patch "clk: lpc32xx: add a quirk for PWM and MS clock dividers" has been added to the 4.9-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    clk: lpc32xx: add a quirk for PWM and MS clock dividers

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     clk-lpc32xx-add-a-quirk-for-pwm-and-ms-clock-dividers.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Mon Apr 10 17:14:09 CEST 2017
From: alexander.levin@verizon.com
Date: Tue, 4 Apr 2017 19:32:03 +0000
Subject: clk: lpc32xx: add a quirk for PWM and MS clock dividers
To: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>
Cc: "stable@vger.kernel.org" <stable@vger.kernel.org>
Message-ID: <20170404193158.19041-3-alexander.levin@verizon.com>

From: Vladimir Zapolskiy <vz@mleia.com>

[ Upstream commit f84d42a9cffc4ecd96f1ce3a038f841782142eb2 ]

In common clock framework CLK_DIVIDER_ONE_BASED or'ed with
CLK_DIVIDER_ALLOW_ZERO flags indicates that
1) a divider clock may be set to zero value,
2) divider's zero value is interpreted as a non-divided clock.

On the LPC32xx platform clock dividers of PWM and memory card clocks
comply with the first condition, but zero value means a gated clock,
thus it may happen that the divider value is not updated when
the clock is enabled and the clock remains gated.

The change adds one-shot quirks, which check for zero value of divider
on initialization and set it to a non-zero value, therefore in runtime
a gate clock will work as expected.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Reviewed-by: Sylvain Lemieux <slemieux.tyco@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/clk/nxp/clk-lpc32xx.c |   32 ++++++++++++++++++++++++++++----
 1 file changed, 28 insertions(+), 4 deletions(-)

--- a/drivers/clk/nxp/clk-lpc32xx.c
+++ b/drivers/clk/nxp/clk-lpc32xx.c
@@ -1282,13 +1282,13 @@ static struct clk_hw_proto clk_hw_proto[
 
 	LPC32XX_DEFINE_MUX(PWM1_MUX, PWMCLK_CTRL, 1, 0x1, NULL, 0),
 	LPC32XX_DEFINE_DIV(PWM1_DIV, PWMCLK_CTRL, 4, 4, NULL,
-			   CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ALLOW_ZERO),
+			   CLK_DIVIDER_ONE_BASED),
 	LPC32XX_DEFINE_GATE(PWM1_GATE, PWMCLK_CTRL, 0, 0),
 	LPC32XX_DEFINE_COMPOSITE(PWM1, PWM1_MUX, PWM1_DIV, PWM1_GATE),
 
 	LPC32XX_DEFINE_MUX(PWM2_MUX, PWMCLK_CTRL, 3, 0x1, NULL, 0),
 	LPC32XX_DEFINE_DIV(PWM2_DIV, PWMCLK_CTRL, 8, 4, NULL,
-			   CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ALLOW_ZERO),
+			   CLK_DIVIDER_ONE_BASED),
 	LPC32XX_DEFINE_GATE(PWM2_GATE, PWMCLK_CTRL, 2, 0),
 	LPC32XX_DEFINE_COMPOSITE(PWM2, PWM2_MUX, PWM2_DIV, PWM2_GATE),
 
@@ -1335,8 +1335,7 @@ static struct clk_hw_proto clk_hw_proto[
 	LPC32XX_DEFINE_GATE(USB_DIV_GATE, USB_CTRL, 17, 0),
 	LPC32XX_DEFINE_COMPOSITE(USB_DIV, _NULL, USB_DIV_DIV, USB_DIV_GATE),
 
-	LPC32XX_DEFINE_DIV(SD_DIV, MS_CTRL, 0, 4, NULL,
-			   CLK_DIVIDER_ONE_BASED | CLK_DIVIDER_ALLOW_ZERO),
+	LPC32XX_DEFINE_DIV(SD_DIV, MS_CTRL, 0, 4, NULL, CLK_DIVIDER_ONE_BASED),
 	LPC32XX_DEFINE_CLK(SD_GATE, MS_CTRL, BIT(5) | BIT(9), BIT(5) | BIT(9),
 			   0x0, BIT(5) | BIT(9), 0x0, 0x0, clk_mask_ops),
 	LPC32XX_DEFINE_COMPOSITE(SD, _NULL, SD_DIV, SD_GATE),
@@ -1478,6 +1477,20 @@ static struct clk * __init lpc32xx_clk_r
 	return clk;
 }
 
+static void __init lpc32xx_clk_div_quirk(u32 reg, u32 div_mask, u32 gate)
+{
+	u32 val;
+
+	regmap_read(clk_regmap, reg, &val);
+
+	if (!(val & div_mask)) {
+		val &= ~gate;
+		val |= BIT(__ffs(div_mask));
+	}
+
+	regmap_update_bits(clk_regmap, reg, gate | div_mask, val);
+}
+
 static void __init lpc32xx_clk_init(struct device_node *np)
 {
 	unsigned int i;
@@ -1517,6 +1530,17 @@ static void __init lpc32xx_clk_init(stru
 		return;
 	}
 
+	/*
+	 * Divider part of PWM and MS clocks requires a quirk to avoid
+	 * a misinterpretation of formally valid zero value in register
+	 * bitfield, which indicates another clock gate. Instead of
+	 * adding complexity to a gate clock ensure that zero value in
+	 * divider clock is never met in runtime.
+	 */
+	lpc32xx_clk_div_quirk(LPC32XX_CLKPWR_PWMCLK_CTRL, 0xf0, BIT(0));
+	lpc32xx_clk_div_quirk(LPC32XX_CLKPWR_PWMCLK_CTRL, 0xf00, BIT(2));
+	lpc32xx_clk_div_quirk(LPC32XX_CLKPWR_MS_CTRL, 0xf, BIT(5) | BIT(9));
+
 	for (i = 1; i < LPC32XX_CLK_MAX; i++) {
 		clk[i] = lpc32xx_clk_register(i);
 		if (IS_ERR(clk[i])) {


Patches currently in stable-queue which might be from gregkh@linuxfoundation.org are

queue-4.9/staging-android-ashmem-lseek-failed-due-to-no-fmode_lseek.patch
queue-4.9/sysfs-be-careful-of-error-returns-from-ops-show.patch
queue-4.9/mips-flush-wrong-invalid-ftlb-entry-for-huge-page.patch
queue-4.9/mips-end-spinlocks-with-.insn.patch
queue-4.9/kvm-arm-arm64-fix-locking-for-kvm_free_stage2_pgd.patch
queue-4.9/powerpc-disable-hfscr-if-tm-is-not-supported.patch
queue-4.9/metag-usercopy-add-missing-fixups.patch
queue-4.9/nios2-reserve-boot-memory-for-device-tree.patch
queue-4.9/ring-buffer-fix-return-value-check-in-test_ringbuffer.patch
queue-4.9/ppdev-check-before-attaching-port.patch
queue-4.9/powerpc-64-fix-flush_-d-i-cache_range-called-from-modules.patch
queue-4.9/drm-sun4i-tcon-move-soc-specific-quirks-to-a-dt-matched-data-structure.patch
queue-4.9/acpi-gpio-do-not-fall-back-to-parsing-_crs-when-we-get-a-deferral.patch
queue-4.9/metag-usercopy-add-early-abort-to-copy_to_user.patch
queue-4.9/powerpc-crypto-crc32c-vpmsum-fix-missing-preempt_disable.patch
queue-4.9/arm-arm64-kvm-take-mmap_sem-in-kvm_arch_prepare_memory_region.patch
queue-4.9/mips-ralink-fix-typos-in-rt3883-pinctrl.patch
queue-4.9/cfg80211-check-rdev-resume-callback-only-for-registered-wiphy.patch
queue-4.9/metag-usercopy-set-flags-before-addz.patch
queue-4.9/metag-usercopy-fix-src-fixup-in-from-user-rapf-loops.patch
queue-4.9/drm-sun4i-add-compatible-string-for-a31-a31s-tcon-timing-controller.patch
queue-4.9/xtensa-make-__pa-work-with-uncached-kseg-addresses.patch
queue-4.9/clk-lpc32xx-add-a-quirk-for-pwm-and-ms-clock-dividers.patch
queue-4.9/powerpc-mm-add-missing-global-tlb-invalidate-if-cxl-is-active.patch
queue-4.9/brcmfmac-use-local-iftype-avoiding-use-after-free-of-virtual-interface.patch
queue-4.9/drm-vmwgfx-remove-getparam-error-message.patch
queue-4.9/mac80211-unconditionally-start-new-netdev-queues-with-itxq-support.patch
queue-4.9/dm-verity-fec-fix-bufio-leaks.patch
queue-4.9/drm-vmwgfx-type-check-lookups-of-fence-objects.patch
queue-4.9/drm-sun4i-add-compatible-strings-for-a31-a31s-display-pipelines.patch
queue-4.9/dm-verity-fec-limit-error-correction-recursion.patch
queue-4.9/s390-uaccess-get_user-should-zero-on-failure-again.patch
queue-4.9/dm-raid-fix-null-pointer-dereference-for-raid1-without-bitmap.patch
queue-4.9/random-use-chacha20-for-get_random_int-long.patch
queue-4.9/ptrace-fix-ptrace_listen-race-corrupting-task-state.patch
queue-4.9/drm-vmwgfx-fix-integer-overflow-in-vmw_surface_define_ioctl.patch
queue-4.9/hid-i2c-hid-add-a-simple-quirk-to-fix-device-defects.patch
queue-4.9/s390-decompressor-fix-initrd-corruption-caused-by-bss-clear.patch
queue-4.9/mips-check-tlb-before-handle_ri_rdhwr-for-loongson-3.patch
queue-4.9/metag-usercopy-drop-unused-macros.patch
queue-4.9/iio-bmg160-reset-chip-when-probing.patch
queue-4.9/orangefs-move-features-validation-to-fix-filesystem-hang.patch
queue-4.9/arm64-mm-unaligned-access-by-user-land-should-be-received-as-sigbus.patch
queue-4.9/powerpc-don-t-try-to-fix-up-misaligned-load-with-reservation-instructions.patch
queue-4.9/mips-lantiq-fix-missing-xbar-kernel-panic.patch
queue-4.9/metag-usercopy-zero-rest-of-buffer-from-copy_from_user.patch
queue-4.9/xfs-honor-falloc_fl_keep_size-when-punching-ends-of-files.patch
queue-4.9/metag-usercopy-fix-alignment-error-checking.patch
queue-4.9/reset-treeid-to-zero-on-smb2-tree_connect.patch
queue-4.9/documentation-stable-kernel-rules-fix-stable-tag-format.patch
queue-4.9/mm-mempolicy.c-fix-error-handling-in-set_mempolicy-and-mbind.patch
queue-4.9/arm-arm64-kvm-take-mmap_sem-in-stage2_unmap_vm.patch
queue-4.9/mm-page_alloc.c-fix-print-order-in-show_free_areas.patch
queue-4.9/hid-usbhid-add-quirks-for-mayflash-dragonrise-gamecube-and-ps3-adapters.patch
queue-4.9/mips-c-r4k-fix-loongson-3-s-vcache-scache-waysize-calculation.patch
queue-4.9/drm-vmwgfx-avoid-calling-vzalloc-with-a-0-size-in-vmw_get_cap_3d_ioctl.patch
queue-4.9/mips-force-o32-fp64-support-on-32bit-mips64r6-kernels.patch
queue-4.9/mips-add-mips_cpu_ftlb-for-loongson-3a-r2.patch
queue-4.9/kbuild-use-cc-disable-warning-consistently-for-maybe-uninitialized.patch
queue-4.9/ppdev-fix-registering-same-device-name.patch
queue-4.9/drm-ttm-drm-vmwgfx-relax-permission-checking-when-opening-surfaces.patch
queue-4.9/drm-vmwgfx-null-pointer-dereference-in-vmw_surface_define_ioctl.patch