On Mon, 26 Aug 2019, Kai-Heng Feng wrote:
> Auto-delink requires writing special registers to ums-realtek device.
> Unconditionally enable auto-delink may break newer devices.
>
> So only enable auto-delink by default for the original three IDs,
> 0x0138, 0x0158 and 0x0159.
>
> Realtek is working on a patch to properly support auto-delink for other
> IDs.
>
> BugLink: https://bugs.launchpad.net/bugs/1838886
> Signed-off-by: Kai-Heng Feng <kai.heng.f...@canonical.com>
> ---
> v2:
> - Use auto_delink_support instead of auto_delink_enable.
>
> drivers/usb/storage/realtek_cr.c | 24 +++++++++++++++++++-----
> 1 file changed, 19 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/usb/storage/realtek_cr.c
> b/drivers/usb/storage/realtek_cr.c
> index beaffac805af..b304cca7c4fa 100644
> --- a/drivers/usb/storage/realtek_cr.c
> +++ b/drivers/usb/storage/realtek_cr.c
> @@ -40,6 +40,10 @@ static int auto_delink_en = 1;
> module_param(auto_delink_en, int, S_IRUGO | S_IWUSR);
> MODULE_PARM_DESC(auto_delink_en, "auto delink mode (0=firmware, 1=software
> [default])");
>
> +static int auto_delink_support = -1;
> +module_param(auto_delink_support, int, S_IRUGO | S_IWUSR);
> +MODULE_PARM_DESC(auto_delink_support, "enable auto delink (-1=auto
> [default], 0=disable, 1=enable)");
> +
> #ifdef CONFIG_REALTEK_AUTOPM
> static int ss_en = 1;
> module_param(ss_en, int, S_IRUGO | S_IWUSR);
> @@ -996,12 +1000,22 @@ static int init_realtek_cr(struct us_data *us)
> goto INIT_FAIL;
> }
>
> - if (CHECK_FW_VER(chip, 0x5888) || CHECK_FW_VER(chip, 0x5889) ||
> - CHECK_FW_VER(chip, 0x5901))
> - SET_AUTO_DELINK(chip);
> - if (STATUS_LEN(chip) == 16) {
> - if (SUPPORT_AUTO_DELINK(chip))
> + if (auto_delink_support == -1) {
> + if (CHECK_PID(chip, 0x0138) || CHECK_PID(chip, 0x0158) ||
> + CHECK_PID(chip, 0x0159))
> + auto_delink_support = 1;
> + else
> + auto_delink_support = 0;
> + }
What will happen if somebody has two Realtek devices plugged in, where
one of them has an old product ID and the other has a new one? You
shouldn't change the value of the module parameter like this.
> +
> + if (auto_delink_support) {
> + if (CHECK_FW_VER(chip, 0x5888) || CHECK_FW_VER(chip, 0x5889) ||
> + CHECK_FW_VER(chip, 0x5901))
> SET_AUTO_DELINK(chip);
> + if (STATUS_LEN(chip) == 16) {
> + if (SUPPORT_AUTO_DELINK(chip))
> + SET_AUTO_DELINK(chip);
> + }
> }
> #ifdef CONFIG_REALTEK_AUTOPM
> if (ss_en)
Instead of adding a new module parameter, how about just changing the
driver's behavior? If a chip doesn't have the right product ID, don't
enable auto_delink regardless of what the module parameter is set to.
Alan Stern
