| Message ID | 20220302220709.3138846-3-mario.limonciello@amd.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 6915812bbd109787ebdb865561dc9164d4b01f56 |
| Headers | show |
| Series | [1/5] drivers/thunderbolt: Retry DROM reads for more failure scenarios | expand |
Hi Mario, On Wed, Mar 02, 2022 at 04:07:07PM -0600, Mario Limonciello wrote: > The USB4 specification doesn't make any requirements that reading > a device router's DROM is needed for the operation of the device. > > On page 207 of the USB4 1.0 spec it does mention that a CM may use > the DROM to make decision though: > ``` > After enumerating a Router, the Connection Manager may read the > contents of the Router’s DROM. If, after reading the contents of > DROM, the Connection Manager decides that it does not want the > Router in its Domain... > ``` You don't need to quote the spec for Thunderbolt patches. I can read, and it's not like it is going to change anyway ;-) > Other connection manager solutions don't necessarily read it or gate > the usability of the device on whether it was read. Indeed. > So make failures when reading the DROM show warnings but not > fail the initialization of the switch. > > Link: https://www.usb.org/sites/default/files/USB4%20Specification%2020211116.zip Also no need to "link" the spec. I know where the spec can be downloaded. Ditto for all patches. > Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> > --- > drivers/thunderbolt/switch.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c > index 294518af4ee4..ac87e8b50e52 100644 > --- a/drivers/thunderbolt/switch.c > +++ b/drivers/thunderbolt/switch.c > @@ -2784,10 +2784,8 @@ int tb_switch_add(struct tb_switch *sw) > > /* read drom */ > ret = tb_drom_read(sw); > - if (ret) { > - dev_err(&sw->dev, "reading DROM failed\n"); > - return ret; > - } > + if (ret) > + dev_warn(&sw->dev, "reading DROM failed: %d\n", ret); > tb_sw_dbg(sw, "uid: %#llx\n", sw->uid); > > tb_check_quirks(sw); > -- > 2.34.1
diff --git a/drivers/thunderbolt/switch.c b/drivers/thunderbolt/switch.c index 294518af4ee4..ac87e8b50e52 100644 --- a/drivers/thunderbolt/switch.c +++ b/drivers/thunderbolt/switch.c @@ -2784,10 +2784,8 @@ int tb_switch_add(struct tb_switch *sw) /* read drom */ ret = tb_drom_read(sw); - if (ret) { - dev_err(&sw->dev, "reading DROM failed\n"); - return ret; - } + if (ret) + dev_warn(&sw->dev, "reading DROM failed: %d\n", ret); tb_sw_dbg(sw, "uid: %#llx\n", sw->uid); tb_check_quirks(sw);
The USB4 specification doesn't make any requirements that reading a device router's DROM is needed for the operation of the device. On page 207 of the USB4 1.0 spec it does mention that a CM may use the DROM to make decision though: ``` After enumerating a Router, the Connection Manager may read the contents of the Router’s DROM. If, after reading the contents of DROM, the Connection Manager decides that it does not want the Router in its Domain... ``` Other connection manager solutions don't necessarily read it or gate the usability of the device on whether it was read. So make failures when reading the DROM show warnings but not fail the initialization of the switch. Link: https://www.usb.org/sites/default/files/USB4%20Specification%2020211116.zip Signed-off-by: Mario Limonciello <mario.limonciello@amd.com> --- drivers/thunderbolt/switch.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)