[PATCH AUTOSEL 4.19 020/106] spi: dw: Enable interrupts in accordance with DMA xfer mode

[PATCH AUTOSEL 4.19 020/106] spi: dw: Enable interrupts in accordance with DMA xfer mode

[Sasha Levin]

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>

[ Upstream commit 43dba9f3f98c2b184a19f856f06fe22817bfd9e0 ]

It's pointless to track the Tx overrun interrupts if Rx-only SPI
transfer is issued. Similarly there is no need in handling the Rx
overrun/underrun interrupts if Tx-only SPI transfer is executed.
So lets unmask the interrupts only if corresponding SPI
transactions are implied.

Co-developed-by: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Signed-off-by: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Link: https://lore.kernel.org/r/20200522000806.7381-3-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/spi/spi-dw-mid.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c
index f7ec8b98e6db..e1b34ef9a31c 100644
--- a/drivers/spi/spi-dw-mid.c
+++ b/drivers/spi/spi-dw-mid.c
@@ -228,19 +228,23 @@ static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws,
 
 static int mid_spi_dma_setup(struct dw_spi *dws, struct spi_transfer *xfer)
 {
-	u16 dma_ctrl = 0;
+	u16 imr = 0, dma_ctrl = 0;
 
 	dw_writel(dws, DW_SPI_DMARDLR, 0xf);
 	dw_writel(dws, DW_SPI_DMATDLR, 0x10);
 
-	if (xfer->tx_buf)
+	if (xfer->tx_buf) {
 		dma_ctrl |= SPI_DMA_TDMAE;
-	if (xfer->rx_buf)
+		imr |= SPI_INT_TXOI;
+	}
+	if (xfer->rx_buf) {
 		dma_ctrl |= SPI_DMA_RDMAE;
+		imr |= SPI_INT_RXUI | SPI_INT_RXOI;
+	}
 	dw_writel(dws, DW_SPI_DMACR, dma_ctrl);
 
 	/* Set the interrupt mask */
-	spi_umask_intr(dws, SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI);
+	spi_umask_intr(dws, imr);
 
 	dws->transfer_handler = dma_transfer;
 
-- 
2.25.1

[PATCH AUTOSEL 4.19 021/106] clocksource: dw_apb_timer: Make CPU-affiliation being optional

[Sasha Levin]

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>

[ Upstream commit cee43dbf2ee3f430434e2b66994eff8a1aeda889 ]

Currently the DW APB Timer driver binds each clockevent timers to a
particular CPU. This isn't good for multiple reasons. First of all seeing
the device is placed on APB bus (which makes it accessible from any CPU
core), accessible over MMIO and having the DYNIRQ flag set we can be sure
that manually binding the timer to any CPU just isn't correct. By doing
so we just set an extra limitation on device usage. This also doesn't
reflect the device actual capability, since by setting the IRQ affinity
we can make it virtually local to any CPU. Secondly imagine if you had a
real CPU-local timer with the same rating and the same CPU-affinity.
In this case if DW APB timer was registered first, then due to the
clockevent framework tick-timer selection procedure we'll end up with the
real CPU-local timer being left unselected for clock-events tracking. But
on most of the platforms (MIPS/ARM/etc) such timers are normally embedded
into the CPU core and are accessible with much better performance then
devices placed on APB. For instance in MIPS architectures there is
r4k-timer, which is CPU-local, assigned with the same rating, and normally
its clockevent device is registered after the platform-specific one.

So in order to fix all of these issues let's make the DW APB Timer CPU
affinity being optional and deactivated by passing a negative CPU id,
which will effectively set the DW APB clockevent timer cpumask to
'cpu_possible_mask'.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-rtc@vger.kernel.org
Cc: devicetree@vger.kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200521204818.25436-5-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/clocksource/dw_apb_timer.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/clocksource/dw_apb_timer.c b/drivers/clocksource/dw_apb_timer.c
index 1f5f734e4919..a018199575e3 100644
--- a/drivers/clocksource/dw_apb_timer.c
+++ b/drivers/clocksource/dw_apb_timer.c
@@ -225,7 +225,8 @@ static int apbt_next_event(unsigned long delta,
 /**
  * dw_apb_clockevent_init() - use an APB timer as a clock_event_device
  *
- * @cpu:	The CPU the events will be targeted at.
+ * @cpu:	The CPU the events will be targeted at or -1 if CPU affiliation
+ *		isn't required.
  * @name:	The name used for the timer and the IRQ for it.
  * @rating:	The rating to give the timer.
  * @base:	I/O base for the timer registers.
@@ -260,7 +261,7 @@ dw_apb_clockevent_init(int cpu, const char *name, unsigned rating,
 	dw_ced->ced.max_delta_ticks = 0x7fffffff;
 	dw_ced->ced.min_delta_ns = clockevent_delta2ns(5000, &dw_ced->ced);
 	dw_ced->ced.min_delta_ticks = 5000;
-	dw_ced->ced.cpumask = cpumask_of(cpu);
+	dw_ced->ced.cpumask = cpu < 0 ? cpu_possible_mask : cpumask_of(cpu);
 	dw_ced->ced.features = CLOCK_EVT_FEAT_PERIODIC |
 				CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_DYNIRQ;
 	dw_ced->ced.set_state_shutdown = apbt_shutdown;
-- 
2.25.1

[PATCH AUTOSEL 4.19 022/106] clocksource: dw_apb_timer_of: Fix missing clockevent timers

[Sasha Levin]

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>

[ Upstream commit 6d2e16a3181bafb77b535095c39ad1c8b9558c8c ]

Commit 100214889973 ("clocksource: dw_apb_timer_of: use
clocksource_of_init") replaced a publicly available driver
initialization method with one called by the timer_probe() method
available after CLKSRC_OF. In current implementation it traverses
all the timers available in the system and calls their initialization
methods if corresponding devices were either in dtb or in acpi. But
if before the commit any number of available timers would be installed
as clockevent and clocksource devices, after that there would be at most
two. The rest are just ignored since default case branch doesn't do
anything. I don't see a reason of such behaviour, neither the commit
message explains it. Moreover this might be wrong if on some platforms
these timers might be used for different purpose, as virtually CPU-local
clockevent timers and as an independent broadcast timer. So in order
to keep the compatibility with the platforms where the order of the
timers detection has some meaning, lets add the secondly discovered
timer to be of clocksource/sched_clock type, while the very first and
the others would provide the clockevents service.

Fixes: 100214889973 ("clocksource: dw_apb_timer_of: use clocksource_of_init")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: linux-rtc@vger.kernel.org
Cc: devicetree@vger.kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200521204818.25436-7-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/clocksource/dw_apb_timer_of.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c
index 69866cd8f4bb..3e4d0e5733d3 100644
--- a/drivers/clocksource/dw_apb_timer_of.c
+++ b/drivers/clocksource/dw_apb_timer_of.c
@@ -146,10 +146,6 @@ static int num_called;
 static int __init dw_apb_timer_init(struct device_node *timer)
 {
 	switch (num_called) {
-	case 0:
-		pr_debug("%s: found clockevent timer\n", __func__);
-		add_clockevent(timer);
-		break;
 	case 1:
 		pr_debug("%s: found clocksource timer\n", __func__);
 		add_clocksource(timer);
@@ -160,6 +156,8 @@ static int __init dw_apb_timer_init(struct device_node *timer)
 #endif
 		break;
 	default:
+		pr_debug("%s: found clockevent timer\n", __func__);
+		add_clockevent(timer);
 		break;
 	}
 
-- 
2.25.1

[PATCH AUTOSEL 4.19 027/106] spi: dw: Fix Rx-only DMA transfers

[Sasha Levin]

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>

[ Upstream commit 46164fde6b7890e7a3982d54549947c8394c0192 ]

Tx-only DMA transfers are working perfectly fine since in this case
the code just ignores the Rx FIFO overflow interrupts. But it turns
out the SPI Rx-only transfers are broken since nothing pushing any
data to the shift registers, so the Rx FIFO is left empty and the
SPI core subsystems just returns a timeout error. Since DW DMAC
driver doesn't support something like cyclic write operations of
a single byte to a device register, the only way to support the
Rx-only SPI transfers is to fake it by using a dummy Tx-buffer.
This is what we intend to fix in this commit by setting the
SPI_CONTROLLER_MUST_TX flag for DMA-capable platform.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Link: https://lore.kernel.org/r/20200529131205.31838-9-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/spi/spi-dw.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index 5a47e28e38c1..2207bf17f6a6 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -530,6 +530,7 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws)
 			dws->dma_inited = 0;
 		} else {
 			master->can_dma = dws->dma_ops->can_dma;
+			master->flags |= SPI_CONTROLLER_MUST_TX;
 		}
 	}
 
-- 
2.25.1

[PATCH AUTOSEL 4.19 036/106] dt-bindings: display: mediatek: control dpi pins mode to avoid leakage

[Sasha Levin]

From: Jitao Shi <jitao.shi@mediatek.com>

[ Upstream commit b0ff9b590733079f7f9453e5976a9dd2630949e3 ]

Add property "pinctrl-names" to swap pin mode between gpio and dpi mode.
Set the dpi pins to gpio mode and output-low to avoid leakage current
when dpi disabled.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Jitao Shi <jitao.shi@mediatek.com>
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 .../devicetree/bindings/display/mediatek/mediatek,dpi.txt   | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/mediatek/mediatek,dpi.txt b/Documentation/devicetree/bindings/display/mediatek/mediatek,dpi.txt
index b6a7e7397b8b..b944fe067188 100644
--- a/Documentation/devicetree/bindings/display/mediatek/mediatek,dpi.txt
+++ b/Documentation/devicetree/bindings/display/mediatek/mediatek,dpi.txt
@@ -16,6 +16,9 @@ Required properties:
   Documentation/devicetree/bindings/graph.txt. This port should be connected
   to the input port of an attached HDMI or LVDS encoder chip.
 
+Optional properties:
+- pinctrl-names: Contain "default" and "sleep".
+
 Example:
 
 dpi0: dpi@1401d000 {
@@ -26,6 +29,9 @@ dpi0: dpi@1401d000 {
 		 <&mmsys CLK_MM_DPI_ENGINE>,
 		 <&apmixedsys CLK_APMIXED_TVDPLL>;
 	clock-names = "pixel", "engine", "pll";
+	pinctrl-names = "default", "sleep";
+	pinctrl-0 = <&dpi_pin_func>;
+	pinctrl-1 = <&dpi_pin_idle>;
 
 	port {
 		dpi0_out: endpoint {
-- 
2.25.1

[PATCH AUTOSEL 4.19 059/106] mips: cm: Fix an invalid error code of INTVN_*_ERR

[Sasha Levin]

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>

[ Upstream commit 8a0efb8b101665a843205eab3d67ab09cb2d9a8d ]

Commit 3885c2b463f6 ("MIPS: CM: Add support for reporting CM cache
errors") adds cm2_causes[] array with map of error type ID and
pointers to the short description string. There is a mistake in
the table, since according to MIPS32 manual CM2_ERROR_TYPE = {17,18}
correspond to INTVN_WR_ERR and INTVN_RD_ERR, while the table
claims they have {0x17,0x18} codes. This is obviously hex-dec
copy-paste bug. Moreover codes {0x18 - 0x1a} indicate L2 ECC errors.

Fixes: 3885c2b463f6 ("MIPS: CM: Add support for reporting CM cache errors")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-pm@vger.kernel.org
Cc: devicetree@vger.kernel.org
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/mips/kernel/mips-cm.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/mips/kernel/mips-cm.c b/arch/mips/kernel/mips-cm.c
index 7f3f136572de..50d3d74001cb 100644
--- a/arch/mips/kernel/mips-cm.c
+++ b/arch/mips/kernel/mips-cm.c
@@ -123,9 +123,9 @@ static char *cm2_causes[32] = {
 	"COH_RD_ERR", "MMIO_WR_ERR", "MMIO_RD_ERR", "0x07",
 	"0x08", "0x09", "0x0a", "0x0b",
 	"0x0c", "0x0d", "0x0e", "0x0f",
-	"0x10", "0x11", "0x12", "0x13",
-	"0x14", "0x15", "0x16", "INTVN_WR_ERR",
-	"INTVN_RD_ERR", "0x19", "0x1a", "0x1b",
+	"0x10", "INTVN_WR_ERR", "INTVN_RD_ERR", "0x13",
+	"0x14", "0x15", "0x16", "0x17",
+	"0x18", "0x19", "0x1a", "0x1b",
 	"0x1c", "0x1d", "0x1e", "0x1f"
 };
 
-- 
2.25.1

[PATCH AUTOSEL 4.19 079/106] mips: MAAR: Use more precise address mask

[Sasha Levin]

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>

[ Upstream commit bbb5946eb545fab8ad8f46bce8a803e1c0c39d47 ]

Indeed according to the MIPS32 Privileged Resource Architecgture the MAAR
pair register address field either takes [12:31] bits for non-XPA systems
and [12:55] otherwise. In any case the current address mask is just
wrong for 64-bit and 32-bits XPA chips. So lets extend it to 59-bits
of physical address value. This shall cover the 64-bits architecture and
systems with XPA enabled, and won't cause any problem for non-XPA 32-bit
systems, since address values exceeding the architecture specific MAAR
mask will be just truncated with setting zeros in the unsupported upper
bits.

Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/mips/include/asm/mipsregs.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/include/asm/mipsregs.h b/arch/mips/include/asm/mipsregs.h
index 1bb9448777c5..f9a7c137be9f 100644
--- a/arch/mips/include/asm/mipsregs.h
+++ b/arch/mips/include/asm/mipsregs.h
@@ -749,7 +749,7 @@
 
 /* MAAR bit definitions */
 #define MIPS_MAAR_VH		(_U64CAST_(1) << 63)
-#define MIPS_MAAR_ADDR		((BIT_ULL(BITS_PER_LONG - 12) - 1) << 12)
+#define MIPS_MAAR_ADDR		GENMASK_ULL(55, 12)
 #define MIPS_MAAR_ADDR_SHIFT	12
 #define MIPS_MAAR_S		(_ULCAST_(1) << 1)
 #define MIPS_MAAR_VL		(_ULCAST_(1) << 0)
-- 
2.25.1

[PATCH AUTOSEL 4.19 080/106] mips: Add udelay lpj numbers adjustment

[Sasha Levin]

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>

[ Upstream commit ed26aacfb5f71eecb20a51c4467da440cb719d66 ]

Loops-per-jiffies is a special number which represents a number of
noop-loop cycles per CPU-scheduler quantum - jiffies. As you
understand aside from CPU-specific implementation it depends on
the CPU frequency. So when a platform has the CPU frequency fixed,
we have no problem and the current udelay interface will work
just fine. But as soon as CPU-freq driver is enabled and the cores
frequency changes, we'll end up with distorted udelay's. In order
to fix this we have to accordinly adjust the per-CPU udelay_val
(the same as the global loops_per_jiffy) number. This can be done
in the CPU-freq transition event handler. We subscribe to that event
in the MIPS arch time-inititalization method.

Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/mips/kernel/time.c | 70 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)

diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c
index bfe02ded25d1..1e631a484ddf 100644
--- a/arch/mips/kernel/time.c
+++ b/arch/mips/kernel/time.c
@@ -22,12 +22,82 @@
 #include <linux/smp.h>
 #include <linux/spinlock.h>
 #include <linux/export.h>
+#include <linux/cpufreq.h>
+#include <linux/delay.h>
 
 #include <asm/cpu-features.h>
 #include <asm/cpu-type.h>
 #include <asm/div64.h>
 #include <asm/time.h>
 
+#ifdef CONFIG_CPU_FREQ
+
+static DEFINE_PER_CPU(unsigned long, pcp_lpj_ref);
+static DEFINE_PER_CPU(unsigned long, pcp_lpj_ref_freq);
+static unsigned long glb_lpj_ref;
+static unsigned long glb_lpj_ref_freq;
+
+static int cpufreq_callback(struct notifier_block *nb,
+			    unsigned long val, void *data)
+{
+	struct cpufreq_freqs *freq = data;
+	struct cpumask *cpus = freq->policy->cpus;
+	unsigned long lpj;
+	int cpu;
+
+	/*
+	 * Skip lpj numbers adjustment if the CPU-freq transition is safe for
+	 * the loops delay. (Is this possible?)
+	 */
+	if (freq->flags & CPUFREQ_CONST_LOOPS)
+		return NOTIFY_OK;
+
+	/* Save the initial values of the lpjes for future scaling. */
+	if (!glb_lpj_ref) {
+		glb_lpj_ref = boot_cpu_data.udelay_val;
+		glb_lpj_ref_freq = freq->old;
+
+		for_each_online_cpu(cpu) {
+			per_cpu(pcp_lpj_ref, cpu) =
+				cpu_data[cpu].udelay_val;
+			per_cpu(pcp_lpj_ref_freq, cpu) = freq->old;
+		}
+	}
+
+	/*
+	 * Adjust global lpj variable and per-CPU udelay_val number in
+	 * accordance with the new CPU frequency.
+	 */
+	if ((val == CPUFREQ_PRECHANGE  && freq->old < freq->new) ||
+	    (val == CPUFREQ_POSTCHANGE && freq->old > freq->new)) {
+		loops_per_jiffy = cpufreq_scale(glb_lpj_ref,
+						glb_lpj_ref_freq,
+						freq->new);
+
+		for_each_cpu(cpu, cpus) {
+			lpj = cpufreq_scale(per_cpu(pcp_lpj_ref, cpu),
+					    per_cpu(pcp_lpj_ref_freq, cpu),
+					    freq->new);
+			cpu_data[cpu].udelay_val = (unsigned int)lpj;
+		}
+	}
+
+	return NOTIFY_OK;
+}
+
+static struct notifier_block cpufreq_notifier = {
+	.notifier_call  = cpufreq_callback,
+};
+
+static int __init register_cpufreq_notifier(void)
+{
+	return cpufreq_register_notifier(&cpufreq_notifier,
+					 CPUFREQ_TRANSITION_NOTIFIER);
+}
+core_initcall(register_cpufreq_notifier);
+
+#endif /* CONFIG_CPU_FREQ */
+
 /*
  * forward reference
  */
-- 
2.25.1

Re: [PATCH AUTOSEL 4.19 080/106] mips: Add udelay lpj numbers adjustment

[Aurelien Jarno]

On 2020-06-08 19:22, Sasha Levin wrote:
> From: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> 
> [ Upstream commit ed26aacfb5f71eecb20a51c4467da440cb719d66 ]
> 
> Loops-per-jiffies is a special number which represents a number of
> noop-loop cycles per CPU-scheduler quantum - jiffies. As you
> understand aside from CPU-specific implementation it depends on
> the CPU frequency. So when a platform has the CPU frequency fixed,
> we have no problem and the current udelay interface will work
> just fine. But as soon as CPU-freq driver is enabled and the cores
> frequency changes, we'll end up with distorted udelay's. In order
> to fix this we have to accordinly adjust the per-CPU udelay_val
> (the same as the global loops_per_jiffy) number. This can be done
> in the CPU-freq transition event handler. We subscribe to that event
> in the MIPS arch time-inititalization method.
> 
> Co-developed-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Signed-off-by: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
> Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
> Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Cc: Paul Burton <paulburton@kernel.org>
> Cc: Ralf Baechle <ralf@linux-mips.org>
> Cc: Arnd Bergmann <arnd@arndb.de>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: devicetree@vger.kernel.org
> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
> Signed-off-by: Sasha Levin <sashal@kernel.org>
> ---
>  arch/mips/kernel/time.c | 70 +++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 70 insertions(+)
> 
> diff --git a/arch/mips/kernel/time.c b/arch/mips/kernel/time.c
> index bfe02ded25d1..1e631a484ddf 100644
> --- a/arch/mips/kernel/time.c
> +++ b/arch/mips/kernel/time.c
> @@ -22,12 +22,82 @@
>  #include <linux/smp.h>
>  #include <linux/spinlock.h>
>  #include <linux/export.h>
> +#include <linux/cpufreq.h>
> +#include <linux/delay.h>
>  
>  #include <asm/cpu-features.h>
>  #include <asm/cpu-type.h>
>  #include <asm/div64.h>
>  #include <asm/time.h>
>  
> +#ifdef CONFIG_CPU_FREQ
> +
> +static DEFINE_PER_CPU(unsigned long, pcp_lpj_ref);
> +static DEFINE_PER_CPU(unsigned long, pcp_lpj_ref_freq);
> +static unsigned long glb_lpj_ref;
> +static unsigned long glb_lpj_ref_freq;
> +
> +static int cpufreq_callback(struct notifier_block *nb,
> +			    unsigned long val, void *data)
> +{
> +	struct cpufreq_freqs *freq = data;
> +	struct cpumask *cpus = freq->policy->cpus;
                                     ^^^^^^

The policy member has been added in kernel 5.2, so kernel 4.19.129 and
later do not build anymore when CONFIG_CPU_FREQ=y.

-- 
Aurelien Jarno                          GPG: 4096R/1DDD8C9B
aurelien@aurel32.net                 http://www.aurel32.net

[PATCH AUTOSEL 4.19 099/106] spi: dw: Return any value retrieved from the dma_transfer callback

[Sasha Levin]

From: Serge Semin <Sergey.Semin@baikalelectronics.ru>

[ Upstream commit f0410bbf7d0fb80149e3b17d11d31f5b5197873e ]

DW APB SSI DMA-part of the driver may need to perform the requested
SPI-transfer synchronously. In that case the dma_transfer() callback
will return 0 as a marker of the SPI transfer being finished so the
SPI core doesn't need to wait and may proceed with the SPI message
trasnfers pumping procedure. This will be needed to fix the problem
when DMA transactions are finished, but there is still data left in
the SPI Tx/Rx FIFOs being sent/received. But for now make dma_transfer
to return 1 as the normal dw_spi_transfer_one() method.

Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
Cc: Georgy Vlasov <Georgy.Vlasov@baikalelectronics.ru>
Cc: Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Feng Tang <feng.tang@intel.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Link: https://lore.kernel.org/r/20200529131205.31838-3-Sergey.Semin@baikalelectronics.ru
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/spi/spi-dw-mid.c | 2 +-
 drivers/spi/spi-dw.c     | 7 ++-----
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c
index e1b34ef9a31c..10f328558d55 100644
--- a/drivers/spi/spi-dw-mid.c
+++ b/drivers/spi/spi-dw-mid.c
@@ -274,7 +274,7 @@ static int mid_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer)
 		dma_async_issue_pending(dws->txchan);
 	}
 
-	return 0;
+	return 1;
 }
 
 static void mid_spi_dma_stop(struct dw_spi *dws)
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c
index 2207bf17f6a6..3724ac0f0032 100644
--- a/drivers/spi/spi-dw.c
+++ b/drivers/spi/spi-dw.c
@@ -380,11 +380,8 @@ static int dw_spi_transfer_one(struct spi_controller *master,
 
 	spi_enable_chip(dws, 1);
 
-	if (dws->dma_mapped) {
-		ret = dws->dma_ops->dma_transfer(dws, transfer);
-		if (ret < 0)
-			return ret;
-	}
+	if (dws->dma_mapped)
+		return dws->dma_ops->dma_transfer(dws, transfer);
 
 	if (chip->poll_mode)
 		return poll_transfer(dws);
-- 
2.25.1