Message ID | 20240123143026.v1.1.Iacf5570a66b82b73ef03daa6557e2fc0db10266a@changeid (mailing list archive) |
---|---|
State | Superseded |
Headers | show |
Series | usb: typec: ucsi: Adding support for UCSI 3.0 | expand |
Hi Abhishek, On Tue, Jan 23, 2024 at 2:30 PM Abhishek Pandit-Subedi <abhishekpandit@google.com> wrote: > > From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> > > Between UCSI 1.2 and UCSI 2.0, the size of the MESSAGE_IN region was > increased from 16 to 256. In order to avoid overflowing reads for older > systems, add a mechanism to use the read UCSI version to truncate read > sizes on UCSI v1.2. > > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> I have one nit (mentioned in side-band but reproducing here for consistency), but will defer to the maintainer on that. The above notwithstanding, FWIW: Reviewed-by: Prashant Malani<pmalani@chromium.org> > @@ -1556,6 +1569,15 @@ int ucsi_register(struct ucsi *ucsi) > if (!ucsi->version) > return -ENODEV; > > + /* > + * Version format is JJ.M.N (JJ = Major version, M = Minor version, > + * N = sub-minor version). > + */ > + dev_info(ucsi->dev, "Registered UCSI interface with version %x.%x.%x", > + UCSI_BCD_GET_MAJOR(ucsi->version), > + UCSI_BCD_GET_MINOR(ucsi->version), > + UCSI_BCD_GET_SUBMINOR(ucsi->version)); nit: I think this doesn't need to be dev_info() and can be just dev_dbg(), but will defer to the maintainer. Thanks, -Prashant
On Wed, Jan 24, 2024 at 12:12:26AM -0800, Prashant Malani wrote: > Hi Abhishek, > > On Tue, Jan 23, 2024 at 2:30 PM Abhishek Pandit-Subedi > <abhishekpandit@google.com> wrote: > > > > From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> > > > > Between UCSI 1.2 and UCSI 2.0, the size of the MESSAGE_IN region was > > increased from 16 to 256. In order to avoid overflowing reads for older > > systems, add a mechanism to use the read UCSI version to truncate read > > sizes on UCSI v1.2. > > > > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> > I have one nit (mentioned in side-band but reproducing here for consistency), > but will defer to the maintainer on that. > > The above notwithstanding, FWIW: > Reviewed-by: Prashant Malani<pmalani@chromium.org> > > > @@ -1556,6 +1569,15 @@ int ucsi_register(struct ucsi *ucsi) > > if (!ucsi->version) > > return -ENODEV; > > > > + /* > > + * Version format is JJ.M.N (JJ = Major version, M = Minor version, > > + * N = sub-minor version). > > + */ > > + dev_info(ucsi->dev, "Registered UCSI interface with version %x.%x.%x", > > + UCSI_BCD_GET_MAJOR(ucsi->version), > > + UCSI_BCD_GET_MINOR(ucsi->version), > > + UCSI_BCD_GET_SUBMINOR(ucsi->version)); > > nit: I think this doesn't need to be dev_info() and can be just > dev_dbg(), but will > defer to the maintainer. I think that's okay. Reviewewd-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
On Wed, Jan 24, 2024 at 03:51:58PM +0200, Heikki Krogerus wrote: > On Wed, Jan 24, 2024 at 12:12:26AM -0800, Prashant Malani wrote: > > Hi Abhishek, > > > > On Tue, Jan 23, 2024 at 2:30 PM Abhishek Pandit-Subedi > > <abhishekpandit@google.com> wrote: > > > > > > From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> > > > > > > Between UCSI 1.2 and UCSI 2.0, the size of the MESSAGE_IN region was > > > increased from 16 to 256. In order to avoid overflowing reads for older > > > systems, add a mechanism to use the read UCSI version to truncate read > > > sizes on UCSI v1.2. > > > > > > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> > > I have one nit (mentioned in side-band but reproducing here for consistency), > > but will defer to the maintainer on that. > > > > The above notwithstanding, FWIW: > > Reviewed-by: Prashant Malani<pmalani@chromium.org> > > > > > @@ -1556,6 +1569,15 @@ int ucsi_register(struct ucsi *ucsi) > > > if (!ucsi->version) > > > return -ENODEV; > > > > > > + /* > > > + * Version format is JJ.M.N (JJ = Major version, M = Minor version, > > > + * N = sub-minor version). > > > + */ > > > + dev_info(ucsi->dev, "Registered UCSI interface with version %x.%x.%x", > > > + UCSI_BCD_GET_MAJOR(ucsi->version), > > > + UCSI_BCD_GET_MINOR(ucsi->version), > > > + UCSI_BCD_GET_SUBMINOR(ucsi->version)); > > > > nit: I think this doesn't need to be dev_info() and can be just > > dev_dbg(), but will > > defer to the maintainer. > > I think that's okay. > > Reviewewd-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> No, when drivers are working properly they are quiet, this needs to be dev_dbg(). thanks, greg k-h
Ack. Will make dev_dbg on the next iteration. This seems like a good addition to the style guide too: https://www.kernel.org/doc/html/v6.7/process/coding-style.html#printing-kernel-messages. "When drivers are working properly, they are quiet. Prefer to use DEBUG messages unless something is wrong." What do you think Greg? On Wed, Jan 24, 2024 at 6:17 AM Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > > On Wed, Jan 24, 2024 at 03:51:58PM +0200, Heikki Krogerus wrote: > > On Wed, Jan 24, 2024 at 12:12:26AM -0800, Prashant Malani wrote: > > > Hi Abhishek, > > > > > > On Tue, Jan 23, 2024 at 2:30 PM Abhishek Pandit-Subedi > > > <abhishekpandit@google.com> wrote: > > > > > > > > From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> > > > > > > > > Between UCSI 1.2 and UCSI 2.0, the size of the MESSAGE_IN region was > > > > increased from 16 to 256. In order to avoid overflowing reads for older > > > > systems, add a mechanism to use the read UCSI version to truncate read > > > > sizes on UCSI v1.2. > > > > > > > > Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org> > > > I have one nit (mentioned in side-band but reproducing here for consistency), > > > but will defer to the maintainer on that. > > > > > > The above notwithstanding, FWIW: > > > Reviewed-by: Prashant Malani<pmalani@chromium.org> > > > > > > > @@ -1556,6 +1569,15 @@ int ucsi_register(struct ucsi *ucsi) > > > > if (!ucsi->version) > > > > return -ENODEV; > > > > > > > > + /* > > > > + * Version format is JJ.M.N (JJ = Major version, M = Minor version, > > > > + * N = sub-minor version). > > > > + */ > > > > + dev_info(ucsi->dev, "Registered UCSI interface with version %x.%x.%x", > > > > + UCSI_BCD_GET_MAJOR(ucsi->version), > > > > + UCSI_BCD_GET_MINOR(ucsi->version), > > > > + UCSI_BCD_GET_SUBMINOR(ucsi->version)); > > > > > > nit: I think this doesn't need to be dev_info() and can be just > > > dev_dbg(), but will > > > defer to the maintainer. > > > > I think that's okay. > > > > Reviewewd-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> > > No, when drivers are working properly they are quiet, this needs to be > dev_dbg(). > > thanks, > > greg k-h >
On Wed, Jan 24, 2024 at 10:59:28AM -0800, Abhishek Pandit-Subedi wrote: > Ack. Will make dev_dbg on the next iteration. > > This seems like a good addition to the style guide too: > https://www.kernel.org/doc/html/v6.7/process/coding-style.html#printing-kernel-messages. > "When drivers are working properly, they are quiet. Prefer to use > DEBUG messages unless something is wrong." > > What do you think Greg? I think you need to stop top-posting :) But yes, that would be nice, hopefully people actually notice it there. Would you have read this and seen it? thanks, greg k-h
On Thu, Jan 25, 2024 at 3:16 PM Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote: > > On Wed, Jan 24, 2024 at 10:59:28AM -0800, Abhishek Pandit-Subedi wrote: > > Ack. Will make dev_dbg on the next iteration. > > > > This seems like a good addition to the style guide too: > > https://www.kernel.org/doc/html/v6.7/process/coding-style.html#printing-kernel-messages. > > "When drivers are working properly, they are quiet. Prefer to use > > DEBUG messages unless something is wrong." > > > > What do you think Greg? > > I think you need to stop top-posting :) > > But yes, that would be nice, hopefully people actually notice it there. > Would you have read this and seen it? > > thanks, > > greg k-h I blame gmail web-interface for the top-posting :) Prashant also mentioned the dev_info when we were reviewing this so I did a quick search for "kernel coding style" (to see if there was guidance) before sending this up so I would definitely have noticed it there. In Bluetooth (where I've previously contributed), dev_info is used for printing version info (example: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/bluetooth/btintel.c?h=v6.8-rc1#n337) and it's very useful for debugging so I assumed it was acceptable. The added benefit of this guidance being in the coding style guide is it's a quick change to checkpatch.pl to add a warning for this (and point to the coding style as the source). I'm fairly sure Chromium actually has a lint that warns whenever you use LOG_INFO(...) for similar reasons (too many INFO messages that should be DEBUG). I will send up a patch with the change soon (both to coding style and checkpatch.pl). Thanks, Abhishek
diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index 5392ec698959..4edf785d203b 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -36,6 +36,19 @@ */ #define UCSI_SWAP_TIMEOUT_MS 5000 +static int ucsi_read_message_in(struct ucsi *ucsi, void *buf, + size_t buf_size) +{ + /* + * Below UCSI 2.0, MESSAGE_IN was limited to 16 bytes. Truncate the + * reads here. + */ + if (ucsi->version <= UCSI_VERSION_1_2) + buf_size = min_t(size_t, 16, buf_size); + + return ucsi->ops->read(ucsi, UCSI_MESSAGE_IN, buf, buf_size); +} + static int ucsi_acknowledge_command(struct ucsi *ucsi) { u64 ctrl; @@ -72,7 +85,7 @@ static int ucsi_read_error(struct ucsi *ucsi) if (ret < 0) return ret; - ret = ucsi->ops->read(ucsi, UCSI_MESSAGE_IN, &error, sizeof(error)); + ret = ucsi_read_message_in(ucsi, &error, sizeof(error)); if (ret) return ret; @@ -170,7 +183,7 @@ int ucsi_send_command(struct ucsi *ucsi, u64 command, length = ret; if (data) { - ret = ucsi->ops->read(ucsi, UCSI_MESSAGE_IN, data, size); + ret = ucsi_read_message_in(ucsi, data, size); if (ret) goto out; } @@ -1556,6 +1569,15 @@ int ucsi_register(struct ucsi *ucsi) if (!ucsi->version) return -ENODEV; + /* + * Version format is JJ.M.N (JJ = Major version, M = Minor version, + * N = sub-minor version). + */ + dev_info(ucsi->dev, "Registered UCSI interface with version %x.%x.%x", + UCSI_BCD_GET_MAJOR(ucsi->version), + UCSI_BCD_GET_MINOR(ucsi->version), + UCSI_BCD_GET_SUBMINOR(ucsi->version)); + queue_delayed_work(system_long_wq, &ucsi->work, 0); ucsi_debugfs_register(ucsi); diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h index 6478016d5cb8..bec920fa6b8a 100644 --- a/drivers/usb/typec/ucsi/ucsi.h +++ b/drivers/usb/typec/ucsi/ucsi.h @@ -23,6 +23,17 @@ struct dentry; #define UCSI_CONTROL 8 #define UCSI_MESSAGE_IN 16 #define UCSI_MESSAGE_OUT 32 +#define UCSIv2_MESSAGE_OUT 272 + +/* UCSI versions */ +#define UCSI_VERSION_1_2 0x0120 +#define UCSI_VERSION_2_0 0x0200 +#define UCSI_VERSION_2_1 0x0210 +#define UCSI_VERSION_3_0 0x0300 + +#define UCSI_BCD_GET_MAJOR(_v_) (((_v_) >> 8) & 0xFF) +#define UCSI_BCD_GET_MINOR(_v_) (((_v_) >> 4) & 0x0F) +#define UCSI_BCD_GET_SUBMINOR(_v_) ((_v_) & 0x0F) /* Command Status and Connector Change Indication (CCI) bits */ #define UCSI_CCI_CONNECTOR(_c_) (((_c_) & GENMASK(7, 1)) >> 1)