Date:   Tue, 7 Feb 2023 15:03:30 -0800
From:   Dmitry Torokhov <dmitry.torokhov@gmail.com>
To:     Jiri Kosina <jikos@kernel.org>,
        Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc:     Guenter Roeck <groeck@chromium.org>,
        Allen Ballway <ballway@chromium.org>,
        Hans de Goede <hdegoede@redhat.com>,
        Alistair Francis <alistair@alistair23.me>,
        linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH v2] HID: retain initial quirks set up when creating HID
 devices
Message-ID: <Y+LYwu3Zs13hdVDy@google.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Precedence: bulk

In certain circumstances, such as when creating I2C-connected HID
devices, we want to pass and retain some quirks (axis inversion, etc).
The source of such quirks may be device tree, or DMI data, or something
else not readily available to the HID core itself and therefore cannot
be reconstructed easily. To allow this, introduce "initial_quirks" field
in hid_device structure and use it when determining the final set of
quirks.

This fixes the problem with i2c-hid setting up device-tree sourced
quirks too late and losing them on device rebind, and also allows to
sever the tie between hid-code and i2c-hid when applying DMI-based
quirks.

Fixes: b60d3c803d76 ("HID: i2c-hid-of: Expose the touchscreen-inverted properties")
Fixes: a2f416bf062a ("HID: multitouch: Add quirks for flipped axes")
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Tested-by: Allen Ballway <ballway@chromium.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
---

v2:
- corrected spelling/grammar in the commit message per Guenter
- added reviewed-by/tested-by tags


 drivers/hid/hid-quirks.c                 | 8 +-------
 drivers/hid/i2c-hid/i2c-hid-core.c       | 6 ++++--
 drivers/hid/i2c-hid/i2c-hid-dmi-quirks.c | 1 -
 include/linux/hid.h                      | 1 +
 4 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/hid/hid-quirks.c b/drivers/hid/hid-quirks.c
index 30e35f79def4..66e64350f138 100644
--- a/drivers/hid/hid-quirks.c
+++ b/drivers/hid/hid-quirks.c
@@ -19,7 +19,6 @@
 #include <linux/input/elan-i2c-ids.h>
 
 #include "hid-ids.h"
-#include "i2c-hid/i2c-hid.h"
 
 /*
  * Alphabetically sorted by vendor then product.
@@ -1238,7 +1237,7 @@ EXPORT_SYMBOL_GPL(hid_quirks_exit);
 static unsigned long hid_gets_squirk(const struct hid_device *hdev)
 {
 	const struct hid_device_id *bl_entry;
-	unsigned long quirks = 0;
+	unsigned long quirks = hdev->initial_quirks;
 
 	if (hid_match_id(hdev, hid_ignore_list))
 		quirks |= HID_QUIRK_IGNORE;
@@ -1299,11 +1298,6 @@ unsigned long hid_lookup_quirk(const struct hid_device *hdev)
 		quirks = hid_gets_squirk(hdev);
 	mutex_unlock(&dquirks_lock);
 
-	/* Get quirks specific to I2C devices */
-	if (IS_ENABLED(CONFIG_I2C_DMI_CORE) && IS_ENABLED(CONFIG_DMI) &&
-	    hdev->bus == BUS_I2C)
-		quirks |= i2c_hid_get_dmi_quirks(hdev->vendor, hdev->product);
-
 	return quirks;
 }
 EXPORT_SYMBOL_GPL(hid_lookup_quirk);
diff --git a/drivers/hid/i2c-hid/i2c-hid-core.c b/drivers/hid/i2c-hid/i2c-hid-core.c
index 0ab8f47a84e9..efbba0465eef 100644
--- a/drivers/hid/i2c-hid/i2c-hid-core.c
+++ b/drivers/hid/i2c-hid/i2c-hid-core.c
@@ -1025,6 +1025,10 @@ int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
 	hid->vendor = le16_to_cpu(ihid->hdesc.wVendorID);
 	hid->product = le16_to_cpu(ihid->hdesc.wProductID);
 
+	hid->initial_quirks = quirks;
+	hid->initial_quirks |= i2c_hid_get_dmi_quirks(hid->vendor,
+						      hid->product);
+
 	snprintf(hid->name, sizeof(hid->name), "%s %04X:%04X",
 		 client->name, (u16)hid->vendor, (u16)hid->product);
 	strscpy(hid->phys, dev_name(&client->dev), sizeof(hid->phys));
@@ -1038,8 +1042,6 @@ int i2c_hid_core_probe(struct i2c_client *client, struct i2chid_ops *ops,
 		goto err_mem_free;
 	}
 
-	hid->quirks |= quirks;
-
 	return 0;
 
 err_mem_free:
diff --git a/drivers/hid/i2c-hid/i2c-hid-dmi-quirks.c b/drivers/hid/i2c-hid/i2c-hid-dmi-quirks.c
index 554a7dc28536..210f17c3a0be 100644
--- a/drivers/hid/i2c-hid/i2c-hid-dmi-quirks.c
+++ b/drivers/hid/i2c-hid/i2c-hid-dmi-quirks.c
@@ -492,4 +492,3 @@ u32 i2c_hid_get_dmi_quirks(const u16 vendor, const u16 product)
 
 	return quirks;
 }
-EXPORT_SYMBOL_GPL(i2c_hid_get_dmi_quirks);
diff --git a/include/linux/hid.h b/include/linux/hid.h
index daaac4d7f370..56dac09c99d9 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -622,6 +622,7 @@ struct hid_device {							/* device report descriptor */
 	unsigned long status;						/* see STAT flags above */
 	unsigned claimed;						/* Claimed by hidinput, hiddev? */
 	unsigned quirks;						/* Various quirks the device can pull on us */
+	unsigned initial_quirks;					/* Initial set of quirks supplied when creating device */
 	bool io_started;						/* If IO has started */
 
 	struct list_head inputs;					/* The list of inputs */
-- 
2.39.1.519.gcb327c4b5f-goog


-- 
Dmitry