From e0b4ab3bb92bda8d12f55842614362989d5b2cb3 Mon Sep 17 00:00:00 2001
From: Stephen Boyd <swboyd@chromium.org>
Date: Wed, 13 Sep 2023 14:27:19 -0700
Subject: platform/x86: intel_scu_ipc: Check status after timeout in
busy_loop()
MIME-Version: 1.0
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It's possible for the polling loop in busy_loop() to get scheduled away
for a long time.
status = ipc_read_status(scu); // status = IPC_STATUS_BUSY
<long time scheduled away>
if (!(status & IPC_STATUS_BUSY))
If this happens, then the status bit could change while the task is
scheduled away and this function would never read the status again after
timing out. Instead, the function will return -ETIMEDOUT when it's
possible that scheduling didn't work out and the status bit was cleared.
Bit polling code should always check the bit being polled one more time
after the timeout in case this happens.
Fix this by reading the status once more after the while loop breaks.
The readl_poll_timeout() macro implements all of this, and it is
shorter, so use that macro here to consolidate code and fix this.
There were some concerns with using readl_poll_timeout() because it uses
timekeeping, and timekeeping isn't running early on or during the late
stages of system suspend or early stages of system resume, but an audit
of the code concluded that this code isn't called during those times so
it is safe to use the macro.
Cc: Prashant Malani <pmalani@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Fixes: e7b7ab3847c9 ("platform/x86: intel_scu_ipc: Sleeping is fine when polling")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20230913212723.3055315-2-swboyd@chromium.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
drivers/platform/x86/intel_scu_ipc.c | 19 ++++++++-----------
1 file changed, 8 insertions(+), 11 deletions(-)
diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c
index 6851d10d6582..4c774ee8bb1b 100644
--- a/drivers/platform/x86/intel_scu_ipc.c
+++ b/drivers/platform/x86/intel_scu_ipc.c
@@ -19,6 +19,7 @@
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
+#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/slab.h>
@@ -231,19 +232,15 @@ static inline u32 ipc_data_readl(struct intel_scu_ipc_dev *scu, u32 offset)
/* Wait till scu status is busy */
static inline int busy_loop(struct intel_scu_ipc_dev *scu)
{
- unsigned long end = jiffies + IPC_TIMEOUT;
-
- do {
- u32 status;
-
- status = ipc_read_status(scu);
- if (!(status & IPC_STATUS_BUSY))
- return (status & IPC_STATUS_ERR) ? -EIO : 0;
+ u8 status;
+ int err;
- usleep_range(50, 100);
- } while (time_before(jiffies, end));
+ err = readx_poll_timeout(ipc_read_status, scu, status, !(status & IPC_STATUS_BUSY),
+ 100, jiffies_to_usecs(IPC_TIMEOUT));
+ if (err)
+ return err;
- return -ETIMEDOUT;
+ return (status & IPC_STATUS_ERR) ? -EIO : 0;
}
/* Wait till ipc ioc interrupt is received or timeout in 10 HZ */
--
cgit v1.2.3
From 427fada620733e6474d783ae6037a66eae42bf8c Mon Sep 17 00:00:00 2001
From: Stephen Boyd <swboyd@chromium.org>
Date: Wed, 13 Sep 2023 14:27:20 -0700
Subject: platform/x86: intel_scu_ipc: Check status upon timeout in
ipc_wait_for_interrupt()
It's possible for the completion in ipc_wait_for_interrupt() to timeout,
simply because the interrupt was delayed in being processed. A timeout
in itself is not an error. This driver should check the status register
upon a timeout to ensure that scheduling or interrupt processing delays
don't affect the outcome of the IPC return value.
CPU0 SCU
---- ---
ipc_wait_for_interrupt()
wait_for_completion_timeout(&scu->cmd_complete)
[TIMEOUT] status[IPC_STATUS_BUSY]=0
Fix this problem by reading the status bit in all cases, regardless of
the timeout. If the completion times out, we'll assume the problem was
that the IPC_STATUS_BUSY bit was still set, but if the status bit is
cleared in the meantime we know that we hit some scheduling delay and we
should just check the error bit.
Cc: Prashant Malani <pmalani@chromium.org>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Fixes: ed12f295bfd5 ("ipc: Added support for IPC interrupt mode")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20230913212723.3055315-3-swboyd@chromium.org
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
drivers/platform/x86/intel_scu_ipc.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c
index 4c774ee8bb1b..299c15312acb 100644
--- a/drivers/platform/x86/intel_scu_ipc.c
+++ b/drivers/platform/x86/intel_scu_ipc.c
@@ -248,10 +248,12 @@ static inline int ipc_wait_for_interrupt(struct intel_scu_ipc_dev *scu)
{
int status;
- if (!wait_for_completion_timeout(&scu->cmd_complete, IPC_TIMEOUT))
- return -ETIMEDOUT;
+ wait_for_completion_timeout(&scu->cmd_complete, IPC_TIMEOUT);
status = ipc_read_status(scu);
+ if (status & IPC_STATUS_BUSY)
+ return -ETIMEDOUT;
+
if (status & IPC_STATUS_ERR)
return -EIO;
--
cgit v1.2.3
From efce78584e583226e9a1f6cb2fb555d6ff47c3e7 Mon Sep 17 00:00:00 2001
From: Stephen Boyd <swboyd@chromium.org>
Date: Wed, 13 Sep 2023 14:27:21 -0700
Subject: platform/x86: intel_scu_ipc: Don't override scu in
intel_scu_ipc_dev_simple_command()
MIME-Version: 1.0
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Content-Transfer-Encoding: 8bit
Andy discovered this bug during patch review. The 'scu' argument to this
function shouldn't be overridden by the function itself. It doesn't make
any sense. Looking at the commit history, we see that commit
f57fa18583f5 ("platform/x86: intel_scu_ipc: Introduce new SCU IPC API")
removed the setting of the scu to ipcdev in other functions, but not
this one. That was an oversight. Remove this line so that we stop
overriding the scu instance that is used by this function.
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Closes: https://lore.kernel.org/r/ZPjdZ3xNmBEBvNiS@smile.fi.intel.com
Cc: Prashant Malani <pmalani@chromium.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Fixes: f57fa18583f5 ("platform/x86: intel_scu_ipc: Introduce new SCU IPC API")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20230913212723.3055315-4-swboyd@chromium.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
drivers/platform/x86/intel_scu_ipc.c | 1 -
1 file changed, 1 deletion(-)
diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c
index 299c15312acb..3271f81a9c00 100644
--- a/drivers/platform/x86/intel_scu_ipc.c
+++ b/drivers/platform/x86/intel_scu_ipc.c
@@ -443,7 +443,6 @@ int intel_scu_ipc_dev_simple_command(struct intel_scu_ipc_dev *scu, int cmd,
mutex_unlock(&ipclock);
return -ENODEV;
}
- scu = ipcdev;
cmdval = sub << 12 | cmd;
ipc_command(scu, cmdval);
err = intel_scu_ipc_check_status(scu);
--
cgit v1.2.3
From 85e654c9f722853a595fa941dca60c157b707b86 Mon Sep 17 00:00:00 2001
From: Stephen Boyd <swboyd@chromium.org>
Date: Wed, 13 Sep 2023 14:27:22 -0700
Subject: platform/x86: intel_scu_ipc: Fail IPC send if still busy
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
It's possible for interrupts to get significantly delayed to the point
that callers of intel_scu_ipc_dev_command() and friends can call the
function once, hit a timeout, and call it again while the interrupt
still hasn't been processed. This driver will get seriously confused if
the interrupt is finally processed after the second IPC has been sent
with ipc_command(). It won't know which IPC has been completed. This
could be quite disastrous if calling code assumes something has happened
upon return from intel_scu_ipc_dev_simple_command() when it actually
hasn't.
Let's avoid this scenario by simply returning -EBUSY in this case.
Hopefully higher layers will know to back off or fail gracefully when
this happens. It's all highly unlikely anyway, but it's better to be
correct here as we have no way to know which IPC the status register is
telling us about if we send a second IPC while the previous IPC is still
processing.
Cc: Prashant Malani <pmalani@chromium.org>
Cc: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Fixes: ed12f295bfd5 ("ipc: Added support for IPC interrupt mode")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20230913212723.3055315-5-swboyd@chromium.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
drivers/platform/x86/intel_scu_ipc.c | 40 +++++++++++++++++++++++++-----------
1 file changed, 28 insertions(+), 12 deletions(-)
diff --git a/drivers/platform/x86/intel_scu_ipc.c b/drivers/platform/x86/intel_scu_ipc.c
index 3271f81a9c00..a68df4133403 100644
--- a/drivers/platform/x86/intel_scu_ipc.c
+++ b/drivers/platform/x86/intel_scu_ipc.c
@@ -265,6 +265,24 @@ static int intel_scu_ipc_check_status(struct intel_scu_ipc_dev *scu)
return scu->irq > 0 ? ipc_wait_for_interrupt(scu) : busy_loop(scu);
}
+static struct intel_scu_ipc_dev *intel_scu_ipc_get(struct intel_scu_ipc_dev *scu)
+{
+ u8 status;
+
+ if (!scu)
+ scu = ipcdev;
+ if (!scu)
+ return ERR_PTR(-ENODEV);
+
+ status = ipc_read_status(scu);
+ if (status & IPC_STATUS_BUSY) {
+ dev_dbg(&scu->dev, "device is busy\n");
+ return ERR_PTR(-EBUSY);
+ }
+
+ return scu;
+}
+
/* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */
static int pwr_reg_rdwr(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data,
u32 count, u32 op, u32 id)
@@ -278,11 +296,10 @@ static int pwr_reg_rdwr(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data,
memset(cbuf, 0, sizeof(cbuf));
mutex_lock(&ipclock);
- if (!scu)
- scu = ipcdev;
- if (!scu) {
+ scu = intel_scu_ipc_get(scu);
+ if (IS_ERR(scu)) {
mutex_unlock(&ipclock);
- return -ENODEV;
+ return PTR_ERR(scu);
}
for (nc = 0; nc < count; nc++, offset += 2) {
@@ -437,12 +454,12 @@ int intel_scu_ipc_dev_simple_command(struct intel_scu_ipc_dev *scu, int cmd,
int err;
mutex_lock(&ipclock);
- if (!scu)
- scu = ipcdev;
- if (!scu) {
+ scu = intel_scu_ipc_get(scu);
+ if (IS_ERR(scu)) {
mutex_unlock(&ipclock);
- return -ENODEV;
+ return PTR_ERR(scu);
}
+
cmdval = sub << 12 | cmd;
ipc_command(scu, cmdval);
err = intel_scu_ipc_check_status(scu);
@@ -482,11 +499,10 @@ int intel_scu_ipc_dev_command_with_size(struct intel_scu_ipc_dev *scu, int cmd,
return -EINVAL;
mutex_lock(&ipclock);
- if (!scu)
- scu = ipcdev;
- if (!scu) {
+ scu = intel_scu_ipc_get(scu);
+ if (IS_ERR(scu)) {
mutex_unlock(&ipclock);
- return -ENODEV;
+ return PTR_ERR(scu);
}
memcpy(inbuf, in, inlen);
--
cgit v1.2.3
From 81bf4a4e9cb754e957ab614cde6a3b16244d670b Mon Sep 17 00:00:00 2001
From: Dennis Bonke <admin@dennisbonke.com>
Date: Thu, 14 Sep 2023 15:03:56 +0200
Subject: platform/x86: thinkpad_acpi: Take mutex in hotkey_resume
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
hotkey_status_set expects the hotkey_mutex to be held.
It seems like it was missed here and that gives lockdep
warnings while resuming.
Fixes: 38831eaf7d4c ("platform/x86: thinkpad_acpi: use lockdep annotations")
Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Dennis Bonke <admin@dennisbonke.com>
Link: https://lore.kernel.org/r/20230914130356.235912-1-admin@dennisbonke.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
drivers/platform/x86/thinkpad_acpi.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index d70c89d32534..41584427dc32 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -4116,9 +4116,11 @@ static void hotkey_resume(void)
{
tpacpi_disable_brightness_delay();
+ mutex_lock(&hotkey_mutex);
if (hotkey_status_set(true) < 0 ||
hotkey_mask_set(hotkey_acpi_mask) < 0)
pr_err("error while attempting to reset the event firmware interface\n");
+ mutex_unlock(&hotkey_mutex);
tpacpi_send_radiosw_update();
tpacpi_input_send_tabletsw();
--
cgit v1.2.3
From 069b292b4b1f9c24674ea69533cd14f7492ead80 Mon Sep 17 00:00:00 2001
From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Date: Mon, 18 Sep 2023 13:29:01 +0300
Subject: MAINTAINERS: Add myself into x86 platform driver maintainers
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Hans has been asking for another person to help as the maintainer of
the x86 platform driver because Mark has not been able to find time to
do that. I got asked for the task and have been reviewing the relevant
patches for a while now but lets make it more official by adding the
MAINTAINERS entries.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230918102901.17669-2-ilpo.jarvinen@linux.intel.com
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
MAINTAINERS | 3 +++
1 file changed, 3 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 90f13281d297..b04cbcec521f 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13617,6 +13617,7 @@ F: drivers/net/ethernet/mellanox/mlxfw/
MELLANOX HARDWARE PLATFORM SUPPORT
M: Hans de Goede <hdegoede@redhat.com>
+M: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
M: Mark Gross <markgross@kernel.org>
M: Vadim Pasternak <vadimp@nvidia.com>
L: platform-driver-x86@vger.kernel.org
@@ -14211,6 +14212,7 @@ F: drivers/platform/surface/surface_gpe.c
MICROSOFT SURFACE HARDWARE PLATFORM SUPPORT
M: Hans de Goede <hdegoede@redhat.com>
+M: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
M: Mark Gross <markgross@kernel.org>
M: Maximilian Luz <luzmaximilian@gmail.com>
L: platform-driver-x86@vger.kernel.org
@@ -23424,6 +23426,7 @@ F: drivers/platform/x86/x86-android-tablets/
X86 PLATFORM DRIVERS
M: Hans de Goede <hdegoede@redhat.com>
+M: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
M: Mark Gross <markgross@kernel.org>
L: platform-driver-x86@vger.kernel.org
S: Maintained
--
cgit v1.2.3
From bc3b6f59463ba9f4367a80331213db491766b5a1 Mon Sep 17 00:00:00 2001
From: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Date: Tue, 19 Sep 2023 15:39:48 +0300
Subject: MAINTAINERS: Add x86 platform drivers patchwork
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Add x86 platform drivers patchwork which has been missing from
MAINTAINERS.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20230919123948.1583-1-ilpo.jarvinen@linux.intel.com
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
MAINTAINERS | 1 +
1 file changed, 1 insertion(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index b04cbcec521f..dbf1668dcd84 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -23430,6 +23430,7 @@ M: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
M: Mark Gross <markgross@kernel.org>
L: platform-driver-x86@vger.kernel.org
S: Maintained
+Q: https://patchwork.kernel.org/project/platform-driver-x86/list/
T: git git://git.kernel.org/pub/scm/linux/kernel/git/pdx86/platform-drivers-x86.git
F: drivers/platform/olpc/
F: drivers/platform/x86/
--
cgit v1.2.3