From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Hans de Goede <hdegoede@redhat.com>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.10 16/47] Input: silead - add workaround for x86 BIOS-es which bring the chip up in a stuck state
Date: Thu, 20 May 2021 11:22:14 +0200 [thread overview]
Message-ID: <20210520092054.076179616@linuxfoundation.org> (raw)
In-Reply-To: <20210520092053.559923764@linuxfoundation.org>
From: Hans de Goede <hdegoede@redhat.com>
[ Upstream commit e479187748a8f151a85116a7091c599b121fdea5 ]
Some buggy BIOS-es bring up the touchscreen-controller in a stuck
state where it blocks the I2C bus. Specifically this happens on
the Jumper EZpad 7 tablet model.
After much poking at this problem I have found that the following steps
are necessary to unstuck the chip / bus:
1. Turn off the Silead chip.
2. Try to do an I2C transfer with the chip, this will fail in response to
which the I2C-bus-driver will call: i2c_recover_bus() which will unstuck
the I2C-bus. Note the unstuck-ing of the I2C bus only works if we first
drop the chip of the bus by turning it off.
3. Turn the chip back on.
On the x86/ACPI systems were this problem is seen, step 1. and 3. require
making ACPI calls and dealing with ACPI Power Resources. This commit adds
a workaround which runtime-suspends the chip to turn it off, leaving it up
to the ACPI subsystem to deal with all the ACPI specific details.
There is no good way to detect this bug, so the workaround gets activated
by a new "silead,stuck-controller-bug" boolean device-property. Since this
is only used on x86/ACPI, this will be set by model specific device-props
set by drivers/platform/x86/touchscreen_dmi.c. Therefor this new
device-property is not documented in the DT-bindings.
Dmesg will contain the following messages on systems where the workaround
is activated:
[ 54.309029] silead_ts i2c-MSSL1680:00: [Firmware Bug]: Stuck I2C bus: please ignore the next 'controller timed out' error
[ 55.373593] i2c_designware 808622C1:04: controller timed out
[ 55.582186] silead_ts i2c-MSSL1680:00: Silead chip ID: 0x80360000
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210405202745.16777-1-hdegoede@redhat.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/input/touchscreen/silead.c | 44 +++++++++++++++++++++++++++---
1 file changed, 40 insertions(+), 4 deletions(-)
diff --git a/drivers/input/touchscreen/silead.c b/drivers/input/touchscreen/silead.c
index 8fa2f3b7cfd8..e8b6c3137420 100644
--- a/drivers/input/touchscreen/silead.c
+++ b/drivers/input/touchscreen/silead.c
@@ -20,6 +20,7 @@
#include <linux/input/mt.h>
#include <linux/input/touchscreen.h>
#include <linux/pm.h>
+#include <linux/pm_runtime.h>
#include <linux/irq.h>
#include <linux/regulator/consumer.h>
@@ -335,10 +336,8 @@ static int silead_ts_get_id(struct i2c_client *client)
error = i2c_smbus_read_i2c_block_data(client, SILEAD_REG_ID,
sizeof(chip_id), (u8 *)&chip_id);
- if (error < 0) {
- dev_err(&client->dev, "Chip ID read error %d\n", error);
+ if (error < 0)
return error;
- }
data->chip_id = le32_to_cpu(chip_id);
dev_info(&client->dev, "Silead chip ID: 0x%8X", data->chip_id);
@@ -351,12 +350,49 @@ static int silead_ts_setup(struct i2c_client *client)
int error;
u32 status;
+ /*
+ * Some buggy BIOS-es bring up the chip in a stuck state where it
+ * blocks the I2C bus. The following steps are necessary to
+ * unstuck the chip / bus:
+ * 1. Turn off the Silead chip.
+ * 2. Try to do an I2C transfer with the chip, this will fail in
+ * response to which the I2C-bus-driver will call:
+ * i2c_recover_bus() which will unstuck the I2C-bus. Note the
+ * unstuck-ing of the I2C bus only works if we first drop the
+ * chip off the bus by turning it off.
+ * 3. Turn the chip back on.
+ *
+ * On the x86/ACPI systems were this problem is seen, step 1. and
+ * 3. require making ACPI calls and dealing with ACPI Power
+ * Resources. The workaround below runtime-suspends the chip to
+ * turn it off, leaving it up to the ACPI subsystem to deal with
+ * this.
+ */
+
+ if (device_property_read_bool(&client->dev,
+ "silead,stuck-controller-bug")) {
+ pm_runtime_set_active(&client->dev);
+ pm_runtime_enable(&client->dev);
+ pm_runtime_allow(&client->dev);
+
+ pm_runtime_suspend(&client->dev);
+
+ dev_warn(&client->dev, FW_BUG "Stuck I2C bus: please ignore the next 'controller timed out' error\n");
+ silead_ts_get_id(client);
+
+ /* The forbid will also resume the device */
+ pm_runtime_forbid(&client->dev);
+ pm_runtime_disable(&client->dev);
+ }
+
silead_ts_set_power(client, SILEAD_POWER_OFF);
silead_ts_set_power(client, SILEAD_POWER_ON);
error = silead_ts_get_id(client);
- if (error)
+ if (error) {
+ dev_err(&client->dev, "Chip ID read error %d\n", error);
return error;
+ }
error = silead_ts_init(client);
if (error)
--
2.30.2
next prev parent reply other threads:[~2021-05-20 9:30 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-20 9:21 [PATCH 5.10 00/47] 5.10.39-rc1 review Greg Kroah-Hartman
2021-05-20 9:21 ` [PATCH 5.10 01/47] x86/msr: Fix wr/rdmsr_safe_regs_on_cpu() prototypes Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 02/47] drm/i915/display: fix compiler warning about array overrun Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 03/47] airo: work around stack usage warning Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 04/47] kgdb: fix gcc-11 warning on indentation Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 05/47] usb: sl811-hcd: improve misleading indentation Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 06/47] cxgb4: Fix the -Wmisleading-indentation warning Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 07/47] isdn: capi: fix mismatched prototypes Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 08/47] virtio_net: Do not pull payload in skb->head Greg Kroah-Hartman
2021-05-20 9:22 ` Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 09/47] ARM: 9058/1: cache-v7: refactor v7_invalidate_l1 to avoid clobbering r5/r6 Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 10/47] PCI: thunder: Fix compile testing Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 11/47] dmaengine: dw-edma: Fix crash on loading/unloading driver Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 12/47] ARM: 9066/1: ftrace: pause/unpause function graph tracer in cpu_suspend() Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 13/47] ACPI / hotplug / PCI: Fix reference count leak in enable_slot() Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 14/47] PCI: tegra: Fix runtime PM imbalance in pex_ep_event_pex_rst_deassert() Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 15/47] Input: elants_i2c - do not bind to i2c-hid compatible ACPI instantiated devices Greg Kroah-Hartman
2021-05-20 9:22 ` Greg Kroah-Hartman [this message]
2021-05-20 9:22 ` [PATCH 5.10 17/47] NFS: NFS_INO_REVAL_PAGECACHE should mark the change attribute invalid Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 18/47] um: Mark all kernel symbols as local Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 19/47] um: Disable CONFIG_GCOV with MODULES Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 20/47] PCI: tegra: Add Tegra194 MCFG quirks for ECAM errata Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 21/47] ARM: 9075/1: kernel: Fix interrupted SMC calls Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 22/47] platform/chrome: cros_ec_typec: Add DP mode check Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 23/47] riscv: Use $(LD) instead of $(CC) to link vDSO Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 24/47] scripts/recordmcount.pl: Fix RISC-V regex for clang Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 25/47] riscv: Workaround mcount name prior to clang-13 Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 26/47] scsi: lpfc: Fix illegal memory access on Abort IOCBs Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 27/47] ceph: fix fscache invalidation Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 28/47] ceph: dont clobber i_snap_caps on non-I_NEW inode Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 29/47] ceph: dont allow access to MDS-private inodes Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 30/47] scsi: target: tcmu: Return from tcmu_handle_completions() if cmd_id not found Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 31/47] amdgpu/pm: Prevent force of DCEFCLK on NAVI10 and SIENNA_CICHLID Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 32/47] bridge: Fix possible races between assigning rx_handler_data and setting IFF_BRIDGE_PORT bit Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 33/47] net: hsr: check skb can contain struct hsr_ethhdr in fill_frame_info Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 34/47] nvmet: remove unsupported command noise Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 35/47] drm/amd/display: Fix two cursor duplication when using overlay Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 36/47] gpiolib: acpi: Add quirk to ignore EC wakeups on Dell Venue 10 Pro 5055 Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 37/47] net:CXGB4: fix leak if sk_buff is not used Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 38/47] ALSA: hda: generic: change the DAC ctl name for LO+SPK or LO+HP Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 39/47] block: reexpand iov_iter after read/write Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 40/47] lib: stackdepot: turn depot_lock spinlock to raw_spinlock Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 41/47] net: stmmac: Do not enable RX FIFO overflow interrupts Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 42/47] ip6_gre: proper dev_{hold|put} in ndo_[un]init methods Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 43/47] sit: " Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 44/47] ip6_tunnel: " Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 45/47] ipv6: remove extra dev_hold() for fallback tunnels Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 46/47] tweewide: Fix most Shebang lines Greg Kroah-Hartman
2021-05-20 9:22 ` [PATCH 5.10 47/47] scripts: switch explicitly to Python 3 Greg Kroah-Hartman
2021-05-20 11:24 ` [PATCH 5.10 00/47] 5.10.39-rc1 review Pavel Machek
2021-05-20 12:32 ` Jon Hunter
2021-05-20 12:59 ` Greg Kroah-Hartman
2021-05-20 14:07 ` Fox Chen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210520092054.076179616@linuxfoundation.org \
--to=gregkh@linuxfoundation.org \
--cc=dmitry.torokhov@gmail.com \
--cc=hdegoede@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=sashal@kernel.org \
--cc=stable@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.