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[PATCH 4.4 03/50] ARM: dts: dra7: do not gate cpsw clock due to errata i877

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4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mugunthan V N <mugunthanvnm@ti.com>

commit 0f514e690740e54815441a87708c3326f8aa8709 upstream.

Errata id: i877

Description:
------------
The RGMII 1000 Mbps Transmit timing is based on the output clock
(rgmiin_txc) being driven relative to the rising edge of an internal
clock and the output control/data (rgmiin_txctl/txd) being driven relative
to the falling edge of an internal clock source. If the internal clock
source is allowed to be static low (i.e., disabled) for an extended period
of time then when the clock is actually enabled the timing delta between
the rising edge and falling edge can change over the lifetime of the
device. This can result in the device switching characteristics degrading
over time, and eventually failing to meet the Data Manual Delay Time/Skew
specs.
To maintain RGMII 1000 Mbps IO Timings, SW should minimize the
duration that the Ethernet internal clock source is disabled. Note that
the device reset state for the Ethernet clock is "disabled".
Other RGMII modes (10 Mbps, 100Mbps) are not affected

Workaround:
-----------
If the SoC Ethernet interface(s) are used in RGMII mode at 1000 Mbps,
SW should minimize the time the Ethernet internal clock source is disabled
to a maximum of 200 hours in a device life cycle. This is done by enabling
the clock as early as possible in IPL (QNX) or SPL/u-boot (Linux/Android)
by setting the register CM_GMAC_CLKSTCTRL[1:0]CLKTRCTRL = 0x2:SW_WKUP.

So, do not allow to gate the cpsw clocks using ti,no-idle property in
cpsw node assuming 1000 Mbps is being used all the time. If someone does
not need 1000 Mbps and wants to gate clocks to cpsw, this property needs
to be deleted in their respective board files.

Signed-off-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/arm/boot/dts/dra7.dtsi |   10 ++++++++++
 1 file changed, 10 insertions(+)

--- a/arch/arm/boot/dts/dra7.dtsi
+++ b/arch/arm/boot/dts/dra7.dtsi
@@ -1497,6 +1497,16 @@
 			       0x48485200 0x2E00>;
 			#address-cells = <1>;
 			#size-cells = <1>;
+
+			/*
+			 * Do not allow gating of cpsw clock as workaround
+			 * for errata i877. Keeping internal clock disabled
+			 * causes the device switching characteristics
+			 * to degrade over time and eventually fail to meet
+			 * the data manual delay time/skew specs.
+			 */
+			ti,no-idle;
+
 			/*
 			 * rx_thresh_pend
 			 * rx_pend

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[PATCH 4.4 00/50] 4.4.6-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:10 +0100
  [PATCH 4.4 11/50] KVM: MMU: fix reserved bit check for ept=0/CR0.WP=0/CR4.SMEP=1/EFER.NX=0 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:10 +0100
  [PATCH 4.4 47/50] MIPS: smp.c: Fix uninitialised temp_foreign_map Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:10 +0100
  [PATCH 4.4 10/50] KVM: MMU: fix ept=0/pte.u=1/pte.w=0/CR0.WP=0/CR4.SMEP=1/EFER.NX=0 combo Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:10 +0100
  [PATCH 4.4 14/50] tracing: Fix check for cpu online when event is disabled Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:10 +0100
  [PATCH 4.4 39/50] Revert "drm/radeon/pm: adjust display configuration after powerstate" Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 30/50] mac80211: minstrel_ht: set default tx aggregation timeout to 0 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 21/50] ASoC: wm8958: Fix enum ctl accesses in a wrong type Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 27/50] iwlwifi: mvm: inc pending frames counter also when txing non-sta Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 43/50] userfaultfd: dont block on the last VM updates at exit time Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 32/50] mac80211: check PN correctly for GCMP-encrypted fragmented MPDUs Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 26/50] can: gs_usb: fixed disconnect bug by removing erroneous use of kfree() Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 40/50] powerpc: Fix dedotify for binutils >= 2.26 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 28/50] mac80211: minstrel: Change expected throughput unit back to Kbps Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 33/50] mac80211: Fix Public Action frame RX in AP mode Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 41/50] powerpc/powernv: Add a kmsg_dumper that flushes console output on panic Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 29/50] mac80211: fix use of uninitialised values in RX aggregation Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 22/50] ovl: ignore lower entries when checking purity of non-directory entries Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 04/50] ARM: OMAP2+: hwmod: Introduce ti,no-idle dt property Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 45/50] ovl: fix getcwd() failure after unsuccessful rmdir Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 23/50] ovl: fix working on distributed fs as lower layer Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 03/50] ARM: dts: dra7: do not gate cpsw clock due to errata i877 Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 02/50] ARM: mvebu: fix overlap of Crypto SRAM with PCIe memory window Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 24/50] wext: fix message delay/ordering Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 06/50] kvm: cap halt polling at exactly halt_poll_ns Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 44/50] ovl: copy new uid/gid into overlayfs runtime inode Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 35/50] x86/mm: Fix slow_virt_to_phys() for X86_PAE again Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 42/50] powerpc/powernv: Fix OPAL_CONSOLE_FLUSH prototype and usages Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 34/50] gpu: ipu-v3: Do not bail out on missing optional port nodes Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:20 +0100
  [PATCH 4.4 15/50] dmaengine: at_xdmac: fix residue computation Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:30 +0100
  [PATCH 4.4 25/50] cfg80211/wext: fix message ordering Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:30 +0100
  [PATCH 4.4 20/50] ASoC: wm8994: Fix enum ctl accesses in a wrong type Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:30 +0100
  [PATCH 4.4 19/50] ASoC: samsung: Use IRQ safe spin lock calls Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-14 19:30 +0100
  Re: [PATCH 4.4 00/50] 4.4.6-stable review Shuah Khan <shuahkh@osg.samsung.com> - 2016-03-15 00:20 +0100
    Re: [PATCH 4.4 00/50] 4.4.6-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-16 16:50 +0100
  Re: [PATCH 4.4 00/50] 4.4.6-stable review Guenter Roeck <linux@roeck-us.net> - 2016-03-15 03:40 +0100
    Re: [PATCH 4.4 00/50] 4.4.6-stable review Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-16 16:50 +0100

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