Commit a90c3eae authored by Anatolij Gustschin's avatar Anatolij Gustschin Committed by Wen Zhiwei
Browse files

net: dsa: lan9303: ensure chip reset and wait for READY status 

stable inclusion
from stable-v6.6.57
commit 28a2c3e51d097975521ca9ffbd8b82ea7b8cdc14
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IB2M97

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=28a2c3e51d097975521ca9ffbd8b82ea7b8cdc14



--------------------------------

commit 5c14e51d2d7df49fe0d4e64a12c58d2542f452ff upstream.

Accessing device registers seems to be not reliable, the chip
revision is sometimes detected wrongly (0 instead of expected 1).

Ensure that the chip reset is performed via reset GPIO and then
wait for 'Device Ready' status in HW_CFG register before doing
any register initializations.

Cc: stable@vger.kernel.org
Fixes: a1292595 ("net: dsa: add new DSA switch driver for the SMSC-LAN9303")
Signed-off-by: default avatarAnatolij Gustschin <agust@denx.de>
[alex: reworked using read_poll_timeout()]
Signed-off-by: default avatarAlexander Sverdlin <alexander.sverdlin@siemens.com>
Reviewed-by: default avatarVladimir Oltean <olteanv@gmail.com>
Link: https://patch.msgid.link/20241004113655.3436296-1-alexander.sverdlin@siemens.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarWen Zhiwei <wenzhiwei@kylinos.cn>
parent 4c3ea889

drivers/net/dsa/lan9303-core.c

+29 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
#include <linux/module.h>

#include <linux/gpio/consumer.h>

#include <linux/regmap.h>

#include <linux/iopoll.h>

#include <linux/mutex.h>

#include <linux/mii.h>

#include <linux/of.h>
@@ -839,6 +840,8 @@ static void lan9303_handle_reset(struct lan9303 *chip) 
	if (!chip->reset_gpio)

		return;



	gpiod_set_value_cansleep(chip->reset_gpio, 1);



	if (chip->reset_duration != 0)

		msleep(chip->reset_duration);
@@ -864,8 +867,34 @@ static int lan9303_disable_processing(struct lan9303 *chip) 
static int lan9303_check_device(struct lan9303 *chip)

{

	int ret;

	int err;

	u32 reg;



	/* In I2C-managed configurations this polling loop will clash with

	 * switch's reading of EEPROM right after reset and this behaviour is

	 * not configurable. While lan9303_read() already has quite long retry

	 * timeout, seems not all cases are being detected as arbitration error.

	 *

	 * According to datasheet, EEPROM loader has 30ms timeout (in case of

	 * missing EEPROM).

	 *

	 * Loading of the largest supported EEPROM is expected to take at least

	 * 5.9s.

	 */

	err = read_poll_timeout(lan9303_read, ret,

				!ret && reg & LAN9303_HW_CFG_READY,

				20000, 6000000, false,

				chip->regmap, LAN9303_HW_CFG, &reg);

	if (ret) {

		dev_err(chip->dev, "failed to read HW_CFG reg: %pe\n",

			ERR_PTR(ret));

		return ret;

	}

	if (err) {

		dev_err(chip->dev, "HW_CFG not ready: 0x%08x\n", reg);

		return err;

	}



	ret = lan9303_read(chip->regmap, LAN9303_CHIP_REV, &reg);

	if (ret) {

		dev_err(chip->dev, "failed to read chip revision register: %d\n",