devicetree.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH AUTOSEL 4.19 003/209] ARM: dts: dra7: Enable workaround for errata i870 in PCIe host mode
       [not found] <20191113015025.9685-1-sashal@kernel.org>
@ 2019-11-13  1:46 ` Sasha Levin
  2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 004/209] ARM: dts: omap5: enable OTG role for DWC3 controller Sasha Levin
                   ` (7 subsequent siblings)
  8 siblings, 0 replies; 11+ messages in thread
From: Sasha Levin @ 2019-11-13  1:46 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Vignesh R, Tony Lindgren, Sasha Levin, linux-omap, devicetree

From: Vignesh R <vigneshr@ti.com>

[ Upstream commit b830526f304764753fcb8b4a563a94080e982a6c ]

Add ti,syscon-unaligned-access property to PCIe RC nodes to set
appropriate bits in CTRL_CORE_SMA_SW_7 register to enable workaround for
errata i870.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm/boot/dts/dra7.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/boot/dts/dra7.dtsi b/arch/arm/boot/dts/dra7.dtsi
index 2cb45ddd2ae3b..fc50d6a8e51ab 100644
--- a/arch/arm/boot/dts/dra7.dtsi
+++ b/arch/arm/boot/dts/dra7.dtsi
@@ -336,6 +336,7 @@
 						<0 0 0 2 &pcie1_intc 2>,
 						<0 0 0 3 &pcie1_intc 3>,
 						<0 0 0 4 &pcie1_intc 4>;
+				ti,syscon-unaligned-access = <&scm_conf1 0x14 1>;
 				status = "disabled";
 				pcie1_intc: interrupt-controller {
 					interrupt-controller;
@@ -387,6 +388,7 @@
 						<0 0 0 2 &pcie2_intc 2>,
 						<0 0 0 3 &pcie2_intc 3>,
 						<0 0 0 4 &pcie2_intc 4>;
+				ti,syscon-unaligned-access = <&scm_conf1 0x14 2>;
 				pcie2_intc: interrupt-controller {
 					interrupt-controller;
 					#address-cells = <0>;
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* [PATCH AUTOSEL 4.19 004/209] ARM: dts: omap5: enable OTG role for DWC3 controller
       [not found] <20191113015025.9685-1-sashal@kernel.org>
  2019-11-13  1:46 ` [PATCH AUTOSEL 4.19 003/209] ARM: dts: dra7: Enable workaround for errata i870 in PCIe host mode Sasha Levin
@ 2019-11-13  1:47 ` Sasha Levin
  2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 008/209] ARM: dts: sun8i: h3-h5: ir register size should be the whole memory block Sasha Levin
                   ` (6 subsequent siblings)
  8 siblings, 0 replies; 11+ messages in thread
From: Sasha Levin @ 2019-11-13  1:47 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: H. Nikolaus Schaller, Roger Quadros, Tony Lindgren, Sasha Levin,
	linux-omap, devicetree

From: "H. Nikolaus Schaller" <hns@goldelico.com>

[ Upstream commit 656c1a65ab555ee5c7cd0d6aee8ab82ca3c1795f ]

Since SMPS10 and OTG cable detection extcon are described here, and
work to enable OTG power when an OTG cable is plugged in, we can
define OTG mode in the controller (which is disabled by default in
omap5.dtsi).

Tested on OMAP5EVM and Pyra.

Suggested-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm/boot/dts/omap5-board-common.dtsi | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/boot/dts/omap5-board-common.dtsi b/arch/arm/boot/dts/omap5-board-common.dtsi
index 8b8db9d8e9126..c2dc4199b4ec2 100644
--- a/arch/arm/boot/dts/omap5-board-common.dtsi
+++ b/arch/arm/boot/dts/omap5-board-common.dtsi
@@ -703,6 +703,10 @@
 	vbus-supply = <&smps10_out1_reg>;
 };
 
+&dwc3 {
+	dr_mode = "otg";
+};
+
 &mcspi1 {
 
 };
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* [PATCH AUTOSEL 4.19 008/209] ARM: dts: sun8i: h3-h5: ir register size should be the whole memory block
       [not found] <20191113015025.9685-1-sashal@kernel.org>
  2019-11-13  1:46 ` [PATCH AUTOSEL 4.19 003/209] ARM: dts: dra7: Enable workaround for errata i870 in PCIe host mode Sasha Levin
  2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 004/209] ARM: dts: omap5: enable OTG role for DWC3 controller Sasha Levin
@ 2019-11-13  1:47 ` Sasha Levin
  2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 009/209] ARM: dts: sun8i: h3: bpi-m2-plus: Fix address for external RGMII Ethernet PHY Sasha Levin
                   ` (5 subsequent siblings)
  8 siblings, 0 replies; 11+ messages in thread
From: Sasha Levin @ 2019-11-13  1:47 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Philipp Rossak, Maxime Ripard, Chen-Yu Tsai, Sasha Levin, devicetree

From: Philipp Rossak <embed3d@gmail.com>

[ Upstream commit 6c700289a3e84d5d3f2a95cf27732a7f7fce105b ]

The size of the register should be the size of the whole memory block,
not just the registers, that are needed.

Signed-off-by: Philipp Rossak <embed3d@gmail.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm/boot/dts/sunxi-h3-h5.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/sunxi-h3-h5.dtsi b/arch/arm/boot/dts/sunxi-h3-h5.dtsi
index fc6131315c47f..4b1530ebe4272 100644
--- a/arch/arm/boot/dts/sunxi-h3-h5.dtsi
+++ b/arch/arm/boot/dts/sunxi-h3-h5.dtsi
@@ -816,7 +816,7 @@
 			clock-names = "apb", "ir";
 			resets = <&r_ccu RST_APB0_IR>;
 			interrupts = <GIC_SPI 37 IRQ_TYPE_LEVEL_HIGH>;
-			reg = <0x01f02000 0x40>;
+			reg = <0x01f02000 0x400>;
 			status = "disabled";
 		};
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* [PATCH AUTOSEL 4.19 009/209] ARM: dts: sun8i: h3: bpi-m2-plus: Fix address for external RGMII Ethernet PHY
       [not found] <20191113015025.9685-1-sashal@kernel.org>
                   ` (2 preceding siblings ...)
  2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 008/209] ARM: dts: sun8i: h3-h5: ir register size should be the whole memory block Sasha Levin
@ 2019-11-13  1:47 ` Sasha Levin
  2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 058/209] ARM: dts: at91: sama5d4_xplained: fix addressable nand flash size Sasha Levin
                   ` (4 subsequent siblings)
  8 siblings, 0 replies; 11+ messages in thread
From: Sasha Levin @ 2019-11-13  1:47 UTC (permalink / raw)
  To: linux-kernel, stable; +Cc: Chen-Yu Tsai, Maxime Ripard, Sasha Levin, devicetree

From: Chen-Yu Tsai <wens@csie.org>

[ Upstream commit db9fd9d13e30fc67737ac9893a82e6b095e85a64 ]

The external RTL8211E RGMII Ethernet PHY is configured via external
resistors to use the address 0x1. The 0x0 address is a broadcast address
for this family of PHYs, and should not be used explicitly.

Fixes: 8c7ba536e709 ("ARM: sun8i: bananapi-m2-plus: Enable dwmac-sun8i")
Fixes: 4904337fe34f ("ARM: dts: sunxi: Restore EMAC changes (boards)")
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm/boot/dts/sun8i-h3-bananapi-m2-plus.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/sun8i-h3-bananapi-m2-plus.dts b/arch/arm/boot/dts/sun8i-h3-bananapi-m2-plus.dts
index 30540dc8e0c5f..bdda0d99128e5 100644
--- a/arch/arm/boot/dts/sun8i-h3-bananapi-m2-plus.dts
+++ b/arch/arm/boot/dts/sun8i-h3-bananapi-m2-plus.dts
@@ -140,7 +140,7 @@
 &external_mdio {
 	ext_rgmii_phy: ethernet-phy@1 {
 		compatible = "ethernet-phy-ieee802.3-c22";
-		reg = <0>;
+		reg = <1>;
 	};
 };
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* [PATCH AUTOSEL 4.19 058/209] ARM: dts: at91: sama5d4_xplained: fix addressable nand flash size
       [not found] <20191113015025.9685-1-sashal@kernel.org>
                   ` (3 preceding siblings ...)
  2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 009/209] ARM: dts: sun8i: h3: bpi-m2-plus: Fix address for external RGMII Ethernet PHY Sasha Levin
@ 2019-11-13  1:47 ` Sasha Levin
  2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 059/209] ARM: dts: at91: at91sam9x5cm: " Sasha Levin
                   ` (3 subsequent siblings)
  8 siblings, 0 replies; 11+ messages in thread
From: Sasha Levin @ 2019-11-13  1:47 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Tudor Ambarus, Ludovic Desroches, Sasha Levin, devicetree

From: Tudor Ambarus <tudor.ambarus@microchip.com>

[ Upstream commit df90fc64367ffdb6f1b5c0f0c4940d44832b0174 ]

sama5d4_xplained comes with a 4Gb NAND flash. Increase the rootfs
size to match this limit.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm/boot/dts/at91-sama5d4_xplained.dts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/at91-sama5d4_xplained.dts b/arch/arm/boot/dts/at91-sama5d4_xplained.dts
index 4b7c762d5f223..7d554b9ab27fd 100644
--- a/arch/arm/boot/dts/at91-sama5d4_xplained.dts
+++ b/arch/arm/boot/dts/at91-sama5d4_xplained.dts
@@ -252,7 +252,7 @@
 
 						rootfs@800000 {
 							label = "rootfs";
-							reg = <0x800000 0x0f800000>;
+							reg = <0x800000 0x1f800000>;
 						};
 					};
 				};
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* [PATCH AUTOSEL 4.19 059/209] ARM: dts: at91: at91sam9x5cm: fix addressable nand flash size
       [not found] <20191113015025.9685-1-sashal@kernel.org>
                   ` (4 preceding siblings ...)
  2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 058/209] ARM: dts: at91: sama5d4_xplained: fix addressable nand flash size Sasha Levin
@ 2019-11-13  1:47 ` Sasha Levin
  2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 060/209] ARM: dts: at91: sama5d2_ptc_ek: fix bootloader env offsets Sasha Levin
                   ` (2 subsequent siblings)
  8 siblings, 0 replies; 11+ messages in thread
From: Sasha Levin @ 2019-11-13  1:47 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Tudor Ambarus, Ludovic Desroches, Sasha Levin, devicetree

From: Tudor Ambarus <tudor.ambarus@microchip.com>

[ Upstream commit 6f270d88a0c4a11725afd8fd2001ae408733afbf ]

at91sam9x5cm comes with a 2Gb NAND flash. Fix the rootfs size to
match this limit.

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm/boot/dts/at91sam9x5cm.dtsi | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/at91sam9x5cm.dtsi b/arch/arm/boot/dts/at91sam9x5cm.dtsi
index 4908ee07e6287..993eabe1cf7a5 100644
--- a/arch/arm/boot/dts/at91sam9x5cm.dtsi
+++ b/arch/arm/boot/dts/at91sam9x5cm.dtsi
@@ -100,7 +100,7 @@
 
 						rootfs@800000 {
 							label = "rootfs";
-							reg = <0x800000 0x1f800000>;
+							reg = <0x800000 0x0f800000>;
 						};
 					};
 				};
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* [PATCH AUTOSEL 4.19 060/209] ARM: dts: at91: sama5d2_ptc_ek: fix bootloader env offsets
       [not found] <20191113015025.9685-1-sashal@kernel.org>
                   ` (5 preceding siblings ...)
  2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 059/209] ARM: dts: at91: at91sam9x5cm: " Sasha Levin
@ 2019-11-13  1:47 ` Sasha Levin
  2019-11-13  1:48 ` [PATCH AUTOSEL 4.19 087/209] ARM: dts: da850-lego-ev3: slow down A/DC as much as possible Sasha Levin
  2019-11-13  1:50 ` [PATCH AUTOSEL 4.19 202/209] ARM: dts: omap5: Fix dual-role mode on Super-Speed port Sasha Levin
  8 siblings, 0 replies; 11+ messages in thread
From: Sasha Levin @ 2019-11-13  1:47 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Tudor Ambarus, Ludovic Desroches, Sasha Levin, devicetree

From: Tudor Ambarus <tudor.ambarus@microchip.com>

[ Upstream commit f602b4871c5f7ac01d37d8b285ca947ba7613065 ]

The offsets for the bootloader environment and its redundant partition
were inverted. Fix the addresses to match our nand flash map available at:

http://www.at91.com/linux4sam/pub/Linux4SAM/SambaSubsections//demo_nandflash_map_lnx4sam5x.png

Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts b/arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts
index 3b1baa8605a77..2214bfe7aa205 100644
--- a/arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts
+++ b/arch/arm/boot/dts/at91-sama5d2_ptc_ek.dts
@@ -92,13 +92,13 @@
 							reg = <0x40000 0xc0000>;
 						};
 
-						bootloaderenv@0x100000 {
-							label = "bootloader env";
+						bootloaderenvred@0x100000 {
+							label = "bootloader env redundant";
 							reg = <0x100000 0x40000>;
 						};
 
-						bootloaderenvred@0x140000 {
-							label = "bootloader env redundant";
+						bootloaderenv@0x140000 {
+							label = "bootloader env";
 							reg = <0x140000 0x40000>;
 						};
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* [PATCH AUTOSEL 4.19 087/209] ARM: dts: da850-lego-ev3: slow down A/DC as much as possible
       [not found] <20191113015025.9685-1-sashal@kernel.org>
                   ` (6 preceding siblings ...)
  2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 060/209] ARM: dts: at91: sama5d2_ptc_ek: fix bootloader env offsets Sasha Levin
@ 2019-11-13  1:48 ` Sasha Levin
  2019-11-13 16:10   ` David Lechner
  2019-11-13  1:50 ` [PATCH AUTOSEL 4.19 202/209] ARM: dts: omap5: Fix dual-role mode on Super-Speed port Sasha Levin
  8 siblings, 1 reply; 11+ messages in thread
From: Sasha Levin @ 2019-11-13  1:48 UTC (permalink / raw)
  To: linux-kernel, stable; +Cc: David Lechner, Sekhar Nori, Sasha Levin, devicetree

From: David Lechner <david@lechnology.com>

[ Upstream commit aea4762fb46e048c059ff49565ee33da07c8aeb3 ]

Due to the electrical design of the A/DC circuits on LEGO MINDSTORMS EV3,
if we are reading analog values as fast as possible (i.e. using DMA to
service the SPI) the A/DC chip will read incorrect values - as much as
0.1V off when the SPI is running at 10MHz. (This has to do with the
capacitor charge time when channels are muxed in the A/DC.)

This patch slows down the SPI as much as possible (if CPU is at 456MHz,
SPI runs at 1/2 of that, so 228MHz and has a max prescalar of 256, so
we could get ~891kHz, but we're just rounding it to 1MHz). We also use
the max allowable value for WDELAY to slow things down even more.

These changes reduce the error of the analog values to about 5mV, which
is tolerable.

Commits a3762b13a596 ("spi: spi-davinci: Add support for SPI_CS_WORD")
and e2540da86ef8 ("iio: adc: ti-ads7950: use SPI_CS_WORD to reduce
CPU usage") introduce changes that allow DMA transfers to be used, so
this slow down is needed now.

Signed-off-by: David Lechner <david@lechnology.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm/boot/dts/da850-lego-ev3.dts | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm/boot/dts/da850-lego-ev3.dts b/arch/arm/boot/dts/da850-lego-ev3.dts
index c4729d0e6c196..66fcadf0ba910 100644
--- a/arch/arm/boot/dts/da850-lego-ev3.dts
+++ b/arch/arm/boot/dts/da850-lego-ev3.dts
@@ -352,7 +352,8 @@
 		compatible = "ti,ads7957";
 		reg = <3>;
 		#io-channel-cells = <1>;
-		spi-max-frequency = <10000000>;
+		spi-max-frequency = <1000000>;
+		ti,spi-wdelay = <63>;
 		vref-supply = <&adc_ref>;
 	};
 };
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* [PATCH AUTOSEL 4.19 202/209] ARM: dts: omap5: Fix dual-role mode on Super-Speed port
       [not found] <20191113015025.9685-1-sashal@kernel.org>
                   ` (7 preceding siblings ...)
  2019-11-13  1:48 ` [PATCH AUTOSEL 4.19 087/209] ARM: dts: da850-lego-ev3: slow down A/DC as much as possible Sasha Levin
@ 2019-11-13  1:50 ` Sasha Levin
  8 siblings, 0 replies; 11+ messages in thread
From: Sasha Levin @ 2019-11-13  1:50 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Roger Quadros, H . Nikolaus Schaller, Tony Lindgren, Sasha Levin,
	linux-omap, devicetree

From: Roger Quadros <rogerq@ti.com>

[ Upstream commit a763ecc15d0e37c3a15ff6825183061209832685 ]

OMAP5's Super-Speed USB port has a software mailbox register
that needs to be fed with VBUS and ID events from an external
VBUS/ID comparator.

Without this, Host role will not work correctly.

Fixes: 656c1a65ab55 ("ARM: dts: omap5: enable OTG role for DWC3 controller")
Reported-by: H. Nikolaus Schaller <hns@goldelico.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/arm/boot/dts/omap5-board-common.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/omap5-board-common.dtsi b/arch/arm/boot/dts/omap5-board-common.dtsi
index c2dc4199b4ec2..61a06f6add3ca 100644
--- a/arch/arm/boot/dts/omap5-board-common.dtsi
+++ b/arch/arm/boot/dts/omap5-board-common.dtsi
@@ -704,6 +704,7 @@
 };
 
 &dwc3 {
+	extcon = <&extcon_usb3>;
 	dr_mode = "otg";
 };
 
-- 
2.20.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* Re: [PATCH AUTOSEL 4.19 087/209] ARM: dts: da850-lego-ev3: slow down A/DC as much as possible
  2019-11-13  1:48 ` [PATCH AUTOSEL 4.19 087/209] ARM: dts: da850-lego-ev3: slow down A/DC as much as possible Sasha Levin
@ 2019-11-13 16:10   ` David Lechner
  2019-11-22  3:24     ` Sasha Levin
  0 siblings, 1 reply; 11+ messages in thread
From: David Lechner @ 2019-11-13 16:10 UTC (permalink / raw)
  To: Sasha Levin, linux-kernel, stable; +Cc: Sekhar Nori, devicetree

On 11/12/19 7:48 PM, Sasha Levin wrote:
> From: David Lechner <david@lechnology.com>
> 
> [ Upstream commit aea4762fb46e048c059ff49565ee33da07c8aeb3 ]
> 
> Due to the electrical design of the A/DC circuits on LEGO MINDSTORMS EV3,
> if we are reading analog values as fast as possible (i.e. using DMA to
> service the SPI) the A/DC chip will read incorrect values - as much as
> 0.1V off when the SPI is running at 10MHz. (This has to do with the
> capacitor charge time when channels are muxed in the A/DC.)
> 
> This patch slows down the SPI as much as possible (if CPU is at 456MHz,
> SPI runs at 1/2 of that, so 228MHz and has a max prescalar of 256, so
> we could get ~891kHz, but we're just rounding it to 1MHz). We also use
> the max allowable value for WDELAY to slow things down even more.
> 
> These changes reduce the error of the analog values to about 5mV, which
> is tolerable.
> 
> Commits a3762b13a596 ("spi: spi-davinci: Add support for SPI_CS_WORD")
> and e2540da86ef8 ("iio: adc: ti-ads7950: use SPI_CS_WORD to reduce
> CPU usage") introduce changes that allow DMA transfers to be used, so
> this slow down is needed now.
> 

I doubt that the commits above would be backported, so it does not
make sense to backport this patch.



^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH AUTOSEL 4.19 087/209] ARM: dts: da850-lego-ev3: slow down A/DC as much as possible
  2019-11-13 16:10   ` David Lechner
@ 2019-11-22  3:24     ` Sasha Levin
  0 siblings, 0 replies; 11+ messages in thread
From: Sasha Levin @ 2019-11-22  3:24 UTC (permalink / raw)
  To: David Lechner; +Cc: linux-kernel, stable, Sekhar Nori, devicetree

On Wed, Nov 13, 2019 at 10:10:30AM -0600, David Lechner wrote:
>On 11/12/19 7:48 PM, Sasha Levin wrote:
>>From: David Lechner <david@lechnology.com>
>>
>>[ Upstream commit aea4762fb46e048c059ff49565ee33da07c8aeb3 ]
>>
>>Due to the electrical design of the A/DC circuits on LEGO MINDSTORMS EV3,
>>if we are reading analog values as fast as possible (i.e. using DMA to
>>service the SPI) the A/DC chip will read incorrect values - as much as
>>0.1V off when the SPI is running at 10MHz. (This has to do with the
>>capacitor charge time when channels are muxed in the A/DC.)
>>
>>This patch slows down the SPI as much as possible (if CPU is at 456MHz,
>>SPI runs at 1/2 of that, so 228MHz and has a max prescalar of 256, so
>>we could get ~891kHz, but we're just rounding it to 1MHz). We also use
>>the max allowable value for WDELAY to slow things down even more.
>>
>>These changes reduce the error of the analog values to about 5mV, which
>>is tolerable.
>>
>>Commits a3762b13a596 ("spi: spi-davinci: Add support for SPI_CS_WORD")
>>and e2540da86ef8 ("iio: adc: ti-ads7950: use SPI_CS_WORD to reduce
>>CPU usage") introduce changes that allow DMA transfers to be used, so
>>this slow down is needed now.
>>
>
>I doubt that the commits above would be backported, so it does not
>make sense to backport this patch.

I've dropped it, thanks!

-- 
Thanks,
Sasha

^ permalink raw reply	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2019-11-22  3:24 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
     [not found] <20191113015025.9685-1-sashal@kernel.org>
2019-11-13  1:46 ` [PATCH AUTOSEL 4.19 003/209] ARM: dts: dra7: Enable workaround for errata i870 in PCIe host mode Sasha Levin
2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 004/209] ARM: dts: omap5: enable OTG role for DWC3 controller Sasha Levin
2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 008/209] ARM: dts: sun8i: h3-h5: ir register size should be the whole memory block Sasha Levin
2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 009/209] ARM: dts: sun8i: h3: bpi-m2-plus: Fix address for external RGMII Ethernet PHY Sasha Levin
2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 058/209] ARM: dts: at91: sama5d4_xplained: fix addressable nand flash size Sasha Levin
2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 059/209] ARM: dts: at91: at91sam9x5cm: " Sasha Levin
2019-11-13  1:47 ` [PATCH AUTOSEL 4.19 060/209] ARM: dts: at91: sama5d2_ptc_ek: fix bootloader env offsets Sasha Levin
2019-11-13  1:48 ` [PATCH AUTOSEL 4.19 087/209] ARM: dts: da850-lego-ev3: slow down A/DC as much as possible Sasha Levin
2019-11-13 16:10   ` David Lechner
2019-11-22  3:24     ` Sasha Levin
2019-11-13  1:50 ` [PATCH AUTOSEL 4.19 202/209] ARM: dts: omap5: Fix dual-role mode on Super-Speed port Sasha Levin

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).