On Wed, Oct 25, 2017 at 04:23:01PM -0500, Eddie James wrote: > > > On 10/25/2017 04:12 PM, Guenter Roeck wrote: > >On Wed, Oct 25, 2017 at 02:52:53PM -0500, Eddie James wrote: > >>From: "Edward A. James" <eajames@xxxxxxxxxx> > >> > >>For devices with word data registers, the pmbus core may call read/write > >>word data functions with a page value of -1, in order to perform the > >>operation without setting the page. However, the read/write word data > >>functions accept only unsigned 8-bit page numbers, resulting in setting > >>a page of 0xFF in this situation. This may result in errors or undefined > >>behavior of some devices (specifically the ir35221, which allows the > >>page to be set to 0xFF, but some subsequent operations to read registers > >>may fail). > >> > >Good catch. > > > >Subject came off a bit odd. > > > >[prefix=PATCH] drivers: pmbus: core: Prevent ... > > > >Please use "[PATCH] hwmon: (pmbus/core) Prevent ..." > > Yea I hit = instead of - in "--subject-prefix"... > > > > >This me wonder if we should move the check into pmbus_set_page() > >instead. > > > >int pmbus_set_page(struct i2c_client *client, int page) > >{ > > ... > > if (page >= 0 && page != data->currpage) { > > ... > >} > > > >What do you think ? > > Yea that works well too, and reduces the code size. Though I suppose it > makes the interface slightly less intuitive, as someone might think they can > pass a value larger than u8. At least for the read/write functions, a > negative value has a meaning - "don't change the page." > > Up to you, either way. I'm happy to change it. > Let's do it. Thanks, Guenter > Thanks, > Eddie > > > > >Thanks, > >Guenter > > > >>Signed-off-by: Edward A. James <eajames@xxxxxxxxxx> > >>--- > >> drivers/hwmon/pmbus/pmbus.h | 4 ++-- > >> drivers/hwmon/pmbus/pmbus_core.c | 29 ++++++++++++++++++----------- > >> 2 files changed, 20 insertions(+), 13 deletions(-) > >> > >>diff --git a/drivers/hwmon/pmbus/pmbus.h b/drivers/hwmon/pmbus/pmbus.h > >>index 4efa2bd..4a16da6 100644 > >>--- a/drivers/hwmon/pmbus/pmbus.h > >>+++ b/drivers/hwmon/pmbus/pmbus.h > >>@@ -405,8 +405,8 @@ struct pmbus_driver_info { > >> void pmbus_clear_cache(struct i2c_client *client); > >> int pmbus_set_page(struct i2c_client *client, u8 page); > >>-int pmbus_read_word_data(struct i2c_client *client, u8 page, u8 reg); > >>-int pmbus_write_word_data(struct i2c_client *client, u8 page, u8 reg, u16 word); > >>+int pmbus_read_word_data(struct i2c_client *client, int page, u8 reg); > >>+int pmbus_write_word_data(struct i2c_client *client, int page, u8 reg, u16 word); > >> int pmbus_read_byte_data(struct i2c_client *client, int page, u8 reg); > >> int pmbus_write_byte(struct i2c_client *client, int page, u8 value); > >> int pmbus_write_byte_data(struct i2c_client *client, int page, u8 reg, > >>diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c > >>index 302f0ae..6d6e030 100644 > >>--- a/drivers/hwmon/pmbus/pmbus_core.c > >>+++ b/drivers/hwmon/pmbus/pmbus_core.c > >>@@ -186,13 +186,16 @@ static int _pmbus_write_byte(struct i2c_client *client, int page, u8 value) > >> return pmbus_write_byte(client, page, value); > >> } > >>-int pmbus_write_word_data(struct i2c_client *client, u8 page, u8 reg, u16 word) > >>+int pmbus_write_word_data(struct i2c_client *client, int page, u8 reg, > >>+ u16 word) > >> { > >> int rv; > >>- rv = pmbus_set_page(client, page); > >>- if (rv < 0) > >>- return rv; > >>+ if (page >= 0) { > >>+ rv = pmbus_set_page(client, page); > >>+ if (rv < 0) > >>+ return rv; > >>+ } > >> return i2c_smbus_write_word_data(client, reg, word); > >> } > >>@@ -219,13 +222,15 @@ static int _pmbus_write_word_data(struct i2c_client *client, int page, int reg, > >> return pmbus_write_word_data(client, page, reg, word); > >> } > >>-int pmbus_read_word_data(struct i2c_client *client, u8 page, u8 reg) > >>+int pmbus_read_word_data(struct i2c_client *client, int page, u8 reg) > >> { > >> int rv; > >>- rv = pmbus_set_page(client, page); > >>- if (rv < 0) > >>- return rv; > >>+ if (page >= 0) { > >>+ rv = pmbus_set_page(client, page); > >>+ if (rv < 0) > >>+ return rv; > >>+ } > >> return i2c_smbus_read_word_data(client, reg); > >> } > >>@@ -269,9 +274,11 @@ int pmbus_write_byte_data(struct i2c_client *client, int page, u8 reg, u8 value) > >> { > >> int rv; > >>- rv = pmbus_set_page(client, page); > >>- if (rv < 0) > >>- return rv; > >>+ if (page >= 0) { > >>+ rv = pmbus_set_page(client, page); > >>+ if (rv < 0) > >>+ return rv; > >>+ } > >> return i2c_smbus_write_byte_data(client, reg, value); > >> } > >>-- > >>1.8.3.1 > >> > -- To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html