| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <CAEc3jaAjUHgv7U59u7RSZ7TK9ycXmYs22b6MsHvSjt-_Do7cjg@mail.gmail.com>
Date: Mon, 9 Jun 2025 21:07:52 -0700
From: Roderick Colenbrander <thunderbird2k@...il.com>
To: Cristian Ciocaltea <cristian.ciocaltea@...labora.com>
Cc: Roderick Colenbrander <roderick.colenbrander@...y.com>, Jiri Kosina <jikos@...nel.org>,
Benjamin Tissoires <bentiss@...nel.org>, Henrik Rydberg <rydberg@...math.org>, kernel@...labora.com,
linux-input@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH 01/11] HID: playstation: Make use of bitfield macros
Hi Christian,
Thanks for the effort into this patch. Personally this is a patch I
would rather drop. There is the trade-off between magical numbers and
code readability. I think this patch makes things much less readable.
Having to introduce more macros and FIELD_PREP vs a single bitshift
here and there.
Thanks,
Roderick
On Mon, May 26, 2025 at 5:52 AM Cristian Ciocaltea
<cristian.ciocaltea@...labora.com> wrote:
>
> Improve code readability by replacing open coded bit operations with the
> equivalent bitfield macros.
>
> While at it, vertically align all DS_OUTPUT_* bit constants.
>
> Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@...labora.com>
> ---
> drivers/hid/hid-playstation.c | 68 ++++++++++++++++++++++++++-----------------
> 1 file changed, 41 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/hid/hid-playstation.c b/drivers/hid/hid-playstation.c
> index 1468fb11e39dffc883181663a4ad44252e0a7ebb..538194ce8902fe1383b57ac59743f32838dcb0df 100644
> --- a/drivers/hid/hid-playstation.c
> +++ b/drivers/hid/hid-playstation.c
> @@ -5,6 +5,7 @@
> * Copyright (c) 2020-2022 Sony Interactive Entertainment
> */
>
> +#include <linux/bitfield.h>
> #include <linux/bits.h>
> #include <linux/crc32.h>
> #include <linux/device.h>
> @@ -116,29 +117,41 @@ struct ps_led_info {
> #define DS_STATUS_CHARGING_SHIFT 4
>
> /* Feature version from DualSense Firmware Info report. */
> -#define DS_FEATURE_VERSION(major, minor) ((major & 0xff) << 8 | (minor & 0xff))
> -
> +#define DS_FEATURE_VERSION_MINOR GENMASK(7, 0)
> +#define DS_FEATURE_VERSION_MAJOR GENMASK(15, 8)
> +#define DS_FEATURE_VERSION(major, minor) (FIELD_PREP(DS_FEATURE_VERSION_MAJOR, major) | \
> + FIELD_PREP(DS_FEATURE_VERSION_MINOR, minor))
> /*
> * Status of a DualSense touch point contact.
> * Contact IDs, with highest bit set are 'inactive'
> * and any associated data is then invalid.
> */
> -#define DS_TOUCH_POINT_INACTIVE BIT(7)
> +#define DS_TOUCH_POINT_INACTIVE BIT(7)
> +#define DS_TOUCH_POINT_X_LO GENMASK(7, 0)
> +#define DS_TOUCH_POINT_X_HI GENMASK(11, 8)
> +#define DS_TOUCH_POINT_X(hi, lo) (FIELD_PREP(DS_TOUCH_POINT_X_HI, hi) | \
> + FIELD_PREP(DS_TOUCH_POINT_X_LO, lo))
> +#define DS_TOUCH_POINT_Y_LO GENMASK(3, 0)
> +#define DS_TOUCH_POINT_Y_HI GENMASK(11, 4)
> +#define DS_TOUCH_POINT_Y(hi, lo) (FIELD_PREP(DS_TOUCH_POINT_Y_HI, hi) | \
> + FIELD_PREP(DS_TOUCH_POINT_Y_LO, lo))
>
> /* Magic value required in tag field of Bluetooth output report. */
> -#define DS_OUTPUT_TAG 0x10
> +#define DS_OUTPUT_TAG 0x10
> +#define DS_OUTPUT_SEQ_TAG GENMASK(3, 0)
> +#define DS_OUTPUT_SEQ_NO GENMASK(7, 4)
> /* Flags for DualSense output report. */
> -#define DS_OUTPUT_VALID_FLAG0_COMPATIBLE_VIBRATION BIT(0)
> -#define DS_OUTPUT_VALID_FLAG0_HAPTICS_SELECT BIT(1)
> -#define DS_OUTPUT_VALID_FLAG1_MIC_MUTE_LED_CONTROL_ENABLE BIT(0)
> -#define DS_OUTPUT_VALID_FLAG1_POWER_SAVE_CONTROL_ENABLE BIT(1)
> -#define DS_OUTPUT_VALID_FLAG1_LIGHTBAR_CONTROL_ENABLE BIT(2)
> -#define DS_OUTPUT_VALID_FLAG1_RELEASE_LEDS BIT(3)
> -#define DS_OUTPUT_VALID_FLAG1_PLAYER_INDICATOR_CONTROL_ENABLE BIT(4)
> -#define DS_OUTPUT_VALID_FLAG2_LIGHTBAR_SETUP_CONTROL_ENABLE BIT(1)
> -#define DS_OUTPUT_VALID_FLAG2_COMPATIBLE_VIBRATION2 BIT(2)
> -#define DS_OUTPUT_POWER_SAVE_CONTROL_MIC_MUTE BIT(4)
> -#define DS_OUTPUT_LIGHTBAR_SETUP_LIGHT_OUT BIT(1)
> +#define DS_OUTPUT_VALID_FLAG0_COMPATIBLE_VIBRATION BIT(0)
> +#define DS_OUTPUT_VALID_FLAG0_HAPTICS_SELECT BIT(1)
> +#define DS_OUTPUT_VALID_FLAG1_MIC_MUTE_LED_CONTROL_ENABLE BIT(0)
> +#define DS_OUTPUT_VALID_FLAG1_POWER_SAVE_CONTROL_ENABLE BIT(1)
> +#define DS_OUTPUT_VALID_FLAG1_LIGHTBAR_CONTROL_ENABLE BIT(2)
> +#define DS_OUTPUT_VALID_FLAG1_RELEASE_LEDS BIT(3)
> +#define DS_OUTPUT_VALID_FLAG1_PLAYER_INDICATOR_CONTROL_ENABLE BIT(4)
> +#define DS_OUTPUT_VALID_FLAG2_LIGHTBAR_SETUP_CONTROL_ENABLE BIT(1)
> +#define DS_OUTPUT_VALID_FLAG2_COMPATIBLE_VIBRATION2 BIT(2)
> +#define DS_OUTPUT_POWER_SAVE_CONTROL_MIC_MUTE BIT(4)
> +#define DS_OUTPUT_LIGHTBAR_SETUP_LIGHT_OUT BIT(1)
>
> /* DualSense hardware limits */
> #define DS_ACC_RES_PER_G 8192
> @@ -315,7 +328,9 @@ struct dualsense_output_report {
> * Contact IDs, with highest bit set are 'inactive'
> * and any associated data is then invalid.
> */
> -#define DS4_TOUCH_POINT_INACTIVE BIT(7)
> +#define DS4_TOUCH_POINT_INACTIVE BIT(7)
> +#define DS4_TOUCH_POINT_X(hi, lo) DS_TOUCH_POINT_X(hi, lo)
> +#define DS4_TOUCH_POINT_Y(hi, lo) DS_TOUCH_POINT_Y(hi, lo)
>
> /* Status field of DualShock4 input report. */
> #define DS4_STATUS0_BATTERY_CAPACITY GENMASK(3, 0)
> @@ -1194,7 +1209,8 @@ static void dualsense_init_output_report(struct dualsense *ds, struct dualsense_
> * Highest 4-bit is a sequence number, which needs to be increased
> * every report. Lowest 4-bit is tag and can be zero for now.
> */
> - bt->seq_tag = (ds->output_seq << 4) | 0x0;
> + bt->seq_tag = FIELD_PREP(DS_OUTPUT_SEQ_NO, ds->output_seq) |
> + FIELD_PREP(DS_OUTPUT_SEQ_TAG, 0x0);
> if (++ds->output_seq == 16)
> ds->output_seq = 0;
>
> @@ -1439,11 +1455,10 @@ static int dualsense_parse_report(struct ps_device *ps_dev, struct hid_report *r
> input_mt_report_slot_state(ds->touchpad, MT_TOOL_FINGER, active);
>
> if (active) {
> - int x = (point->x_hi << 8) | point->x_lo;
> - int y = (point->y_hi << 4) | point->y_lo;
> -
> - input_report_abs(ds->touchpad, ABS_MT_POSITION_X, x);
> - input_report_abs(ds->touchpad, ABS_MT_POSITION_Y, y);
> + input_report_abs(ds->touchpad, ABS_MT_POSITION_X,
> + DS_TOUCH_POINT_X(point->x_hi, point->x_lo));
> + input_report_abs(ds->touchpad, ABS_MT_POSITION_Y,
> + DS_TOUCH_POINT_Y(point->y_hi, point->y_lo));
> }
> }
> input_mt_sync_frame(ds->touchpad);
> @@ -2351,11 +2366,10 @@ static int dualshock4_parse_report(struct ps_device *ps_dev, struct hid_report *
> input_mt_report_slot_state(ds4->touchpad, MT_TOOL_FINGER, active);
>
> if (active) {
> - int x = (point->x_hi << 8) | point->x_lo;
> - int y = (point->y_hi << 4) | point->y_lo;
> -
> - input_report_abs(ds4->touchpad, ABS_MT_POSITION_X, x);
> - input_report_abs(ds4->touchpad, ABS_MT_POSITION_Y, y);
> + input_report_abs(ds4->touchpad, ABS_MT_POSITION_X,
> + DS4_TOUCH_POINT_X(point->x_hi, point->x_lo));
> + input_report_abs(ds4->touchpad, ABS_MT_POSITION_Y,
> + DS4_TOUCH_POINT_Y(point->y_hi, point->y_lo));
> }
> }
> input_mt_sync_frame(ds4->touchpad);
>
> --
> 2.49.0
>
>
Powered by blists - more mailing lists