linux_dsm_epyc7002/arch
Mugunthan V N 0f514e6907 ARM: dts: dra7: do not gate cpsw clock due to errata i877
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>
Cc: <stable@vger.kernel.org>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
2016-03-07 01:41:22 -07:00
..
alpha dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
arc dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
arm ARM: dts: dra7: do not gate cpsw clock due to errata i877 2016-03-07 01:41:22 -07:00
arm64 ARM: SoC support for Tegra platforms for v4.5 2016-01-22 17:30:52 -08:00
avr32 dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
blackfin dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
c6x dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
cris Merge branch 'akpm' (patches from Andrew) 2016-01-21 12:32:08 -08:00
frv dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
h8300 Merge branch 'akpm' (patches from Andrew) 2016-01-21 12:32:08 -08:00
hexagon dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
ia64 [IA64] Enable copy_file_range syscall for ia64 2016-01-22 14:20:01 -08:00
m32r m32r: fix m32104ut_defconfig build fail 2016-01-14 16:00:49 -08:00
m68k dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
metag dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
microblaze dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
mips Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2016-01-24 12:50:56 -08:00
mn10300 dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
nios2 dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
openrisc dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
parisc dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
powerpc wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
s390 wrappers for ->i_mutex access 2016-01-22 18:04:28 -05:00
score Merge branch 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2015-10-04 16:31:13 +01:00
sh dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
sparc dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
tile dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
um um: kill pfn_t 2016-01-15 17:56:32 -08:00
unicore32 dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00
x86 pmem: add wb_cache_pmem() to the PMEM API 2016-01-22 17:02:18 -08:00
xtensa dma-mapping: remove <asm-generic/dma-coherent.h> 2016-01-20 17:09:18 -08:00
.gitignore
Kconfig dma-mapping: always provide the dma_map_ops based implementation 2016-01-20 17:09:18 -08:00