2019-08-26 05:44:18

by Kai-Heng Feng

Subject: [PATCH v2 1/2] USB: storage: ums-realtek: Update module parameter description for auto_delink_en

The option named "auto_delink_en" is a bit misleading, as setting it to
false doesn't really disable auto-delink but let auto-delink be firmware
controlled.

Update the description to reflect the real usage of this parameter.

Signed-off-by: Kai-Heng Feng <[email protected]>
---
v2:
- Only update module parameter description.

drivers/usb/storage/realtek_cr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/storage/realtek_cr.c b/drivers/usb/storage/realtek_cr.c
index cc794e25a0b6..beaffac805af 100644
--- a/drivers/usb/storage/realtek_cr.c
+++ b/drivers/usb/storage/realtek_cr.c
@@ -38,7 +38,7 @@ MODULE_LICENSE("GPL");

static int auto_delink_en = 1;
module_param(auto_delink_en, int, S_IRUGO | S_IWUSR);
-MODULE_PARM_DESC(auto_delink_en, "enable auto delink");
+MODULE_PARM_DESC(auto_delink_en, "auto delink mode (0=firmware, 1=software [default])");

#ifdef CONFIG_REALTEK_AUTOPM
static int ss_en = 1;
--
2.17.1

2019-08-26 05:45:58

by Kai-Heng Feng

Subject: [PATCH v2 2/2] USB: storage: ums-realtek: Make auto-delink support optionally

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 <[email protected]>
---
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;
+ }
+
+ 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)
--
2.17.1

2019-08-26 15:56:50

by Alan Stern

Subject: Re: [PATCH v2 2/2] USB: storage: ums-realtek: Make auto-delink support optionally

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 <[email protected]>
> ---
> 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

2019-08-27 16:48:47

by Kai-Heng Feng

Subject: Re: [PATCH v2 2/2] USB: storage: ums-realtek: Make auto-delink support optionally

at 23:55, Alan Stern <[email protected]> wrote:

> 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 <[email protected]>
>> ---
>> 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.

You are right, I didn’t think of that.

>
>> +
>> + 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.

Ok, I think whitelist is a better approach until Realtek comes up with a
long term solution.

Kai-Heng

>
> Alan Stern