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.feng@xxxxxxxxxxxxx> > --- > 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
