| Message ID | 20210112164130.47895-3-wsa+renesas@sang-engineering.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | None | expand |
> +static int adv7511_edid_rd(struct v4l2_subdev *sd, uint16_t len, uint8_t *buf) > { > struct adv7511_state *state = get_adv7511_state(sd); > + s32 len; And 'len' here shadows the function argument :( Ok, I need to resend this patch. Still, looking forward to a comment if an approach like this is acceptable.
Hi Wolfram, On 12/01/2021 17:41, Wolfram Sang wrote: > The open coded version differs from the one in the core in one way: the > buffer will be always copied back, even when the transfer failed. It > looks like it is expected that the sanity check for a correct CRC and > header will bail out later. Nah, it's just a bug. It should have returned and checked the error code, so your patch does the right thing. Regards, Hans > > Use the block read from the I2C core and propagate a potential errno > further to the sanity check. > > Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> > --- > > Note: we could now make the error checking even stronger by checking if > the number of received bytes is I2C_SMBUS_BLOCK_MAX. But to avoid > regressions, I kept the logic as is, i.e. only check for errno. > > drivers/media/i2c/adv7511-v4l2.c | 40 +++++++++++--------------------- > 1 file changed, 14 insertions(+), 26 deletions(-) > > diff --git a/drivers/media/i2c/adv7511-v4l2.c b/drivers/media/i2c/adv7511-v4l2.c > index a3161d709015..0150f76dc6a6 100644 > --- a/drivers/media/i2c/adv7511-v4l2.c > +++ b/drivers/media/i2c/adv7511-v4l2.c > @@ -214,36 +214,24 @@ static inline void adv7511_wr_and_or(struct v4l2_subdev *sd, u8 reg, u8 clr_mask > adv7511_wr(sd, reg, (adv7511_rd(sd, reg) & clr_mask) | val_mask); > } > > -static int adv_smbus_read_i2c_block_data(struct i2c_client *client, > - u8 command, unsigned length, u8 *values) > -{ > - union i2c_smbus_data data; > - int ret; > - > - if (length > I2C_SMBUS_BLOCK_MAX) > - length = I2C_SMBUS_BLOCK_MAX; > - data.block[0] = length; > - > - ret = i2c_smbus_xfer(client->adapter, client->addr, client->flags, > - I2C_SMBUS_READ, command, > - I2C_SMBUS_I2C_BLOCK_DATA, &data); > - memcpy(values, data.block + 1, length); > - return ret; > -} > - > -static void adv7511_edid_rd(struct v4l2_subdev *sd, uint16_t len, uint8_t *buf) > +static int adv7511_edid_rd(struct v4l2_subdev *sd, uint16_t len, uint8_t *buf) > { > struct adv7511_state *state = get_adv7511_state(sd); > + s32 len; > int i; > - int err = 0; > > v4l2_dbg(1, debug, sd, "%s:\n", __func__); > > - for (i = 0; !err && i < len; i += I2C_SMBUS_BLOCK_MAX) > - err = adv_smbus_read_i2c_block_data(state->i2c_edid, i, > + for (i = 0; i < len; i += I2C_SMBUS_BLOCK_MAX) { > + len = i2c_smbus_read_i2c_block_data(state->i2c_edid, i, > I2C_SMBUS_BLOCK_MAX, buf + i); > - if (err) > - v4l2_err(sd, "%s: i2c read error\n", __func__); > + if (len < 0) { > + v4l2_err(sd, "%s: i2c read error\n", __func__); > + return len; > + } > + } > + > + return 0; > } > > static inline int adv7511_cec_read(struct v4l2_subdev *sd, u8 reg) > @@ -1668,20 +1656,20 @@ static bool adv7511_check_edid_status(struct v4l2_subdev *sd) > if (edidRdy & MASK_ADV7511_EDID_RDY) { > int segment = adv7511_rd(sd, 0xc4); > struct adv7511_edid_detect ed; > + int err; > > if (segment >= EDID_MAX_SEGM) { > v4l2_err(sd, "edid segment number too big\n"); > return false; > } > v4l2_dbg(1, debug, sd, "%s: got segment %d\n", __func__, segment); > - adv7511_edid_rd(sd, 256, &state->edid.data[segment * 256]); > + err = adv7511_edid_rd(sd, 256, &state->edid.data[segment * 256]); > adv7511_dbg_dump_edid(2, debug, sd, segment, &state->edid.data[segment * 256]); > if (segment == 0) { > state->edid.blocks = state->edid.data[0x7e] + 1; > v4l2_dbg(1, debug, sd, "%s: %d blocks in total\n", __func__, state->edid.blocks); > } > - if (!edid_verify_crc(sd, segment) || > - !edid_verify_header(sd, segment)) { > + if (err < 0 || !edid_verify_crc(sd, segment) || !edid_verify_header(sd, segment)) { > /* edid crc error, force reread of edid segment */ > v4l2_err(sd, "%s: edid crc or header error\n", __func__); > state->have_monitor = false; >
Hello Hans, I hope you are well! > > The open coded version differs from the one in the core in one way: the > > buffer will be always copied back, even when the transfer failed. It > > looks like it is expected that the sanity check for a correct CRC and > > header will bail out later. > > Nah, it's just a bug. It should have returned and checked the error code, > so your patch does the right thing. I see. So, I will only update the commit message. Thanks for the reviews! All the best, Wolfram
diff --git a/drivers/media/i2c/adv7511-v4l2.c b/drivers/media/i2c/adv7511-v4l2.c index a3161d709015..0150f76dc6a6 100644 --- a/drivers/media/i2c/adv7511-v4l2.c +++ b/drivers/media/i2c/adv7511-v4l2.c @@ -214,36 +214,24 @@ static inline void adv7511_wr_and_or(struct v4l2_subdev *sd, u8 reg, u8 clr_mask adv7511_wr(sd, reg, (adv7511_rd(sd, reg) & clr_mask) | val_mask); } -static int adv_smbus_read_i2c_block_data(struct i2c_client *client, - u8 command, unsigned length, u8 *values) -{ - union i2c_smbus_data data; - int ret; - - if (length > I2C_SMBUS_BLOCK_MAX) - length = I2C_SMBUS_BLOCK_MAX; - data.block[0] = length; - - ret = i2c_smbus_xfer(client->adapter, client->addr, client->flags, - I2C_SMBUS_READ, command, - I2C_SMBUS_I2C_BLOCK_DATA, &data); - memcpy(values, data.block + 1, length); - return ret; -} - -static void adv7511_edid_rd(struct v4l2_subdev *sd, uint16_t len, uint8_t *buf) +static int adv7511_edid_rd(struct v4l2_subdev *sd, uint16_t len, uint8_t *buf) { struct adv7511_state *state = get_adv7511_state(sd); + s32 len; int i; - int err = 0; v4l2_dbg(1, debug, sd, "%s:\n", __func__); - for (i = 0; !err && i < len; i += I2C_SMBUS_BLOCK_MAX) - err = adv_smbus_read_i2c_block_data(state->i2c_edid, i, + for (i = 0; i < len; i += I2C_SMBUS_BLOCK_MAX) { + len = i2c_smbus_read_i2c_block_data(state->i2c_edid, i, I2C_SMBUS_BLOCK_MAX, buf + i); - if (err) - v4l2_err(sd, "%s: i2c read error\n", __func__); + if (len < 0) { + v4l2_err(sd, "%s: i2c read error\n", __func__); + return len; + } + } + + return 0; } static inline int adv7511_cec_read(struct v4l2_subdev *sd, u8 reg) @@ -1668,20 +1656,20 @@ static bool adv7511_check_edid_status(struct v4l2_subdev *sd) if (edidRdy & MASK_ADV7511_EDID_RDY) { int segment = adv7511_rd(sd, 0xc4); struct adv7511_edid_detect ed; + int err; if (segment >= EDID_MAX_SEGM) { v4l2_err(sd, "edid segment number too big\n"); return false; } v4l2_dbg(1, debug, sd, "%s: got segment %d\n", __func__, segment); - adv7511_edid_rd(sd, 256, &state->edid.data[segment * 256]); + err = adv7511_edid_rd(sd, 256, &state->edid.data[segment * 256]); adv7511_dbg_dump_edid(2, debug, sd, segment, &state->edid.data[segment * 256]); if (segment == 0) { state->edid.blocks = state->edid.data[0x7e] + 1; v4l2_dbg(1, debug, sd, "%s: %d blocks in total\n", __func__, state->edid.blocks); } - if (!edid_verify_crc(sd, segment) || - !edid_verify_header(sd, segment)) { + if (err < 0 || !edid_verify_crc(sd, segment) || !edid_verify_header(sd, segment)) { /* edid crc error, force reread of edid segment */ v4l2_err(sd, "%s: edid crc or header error\n", __func__); state->have_monitor = false;
The open coded version differs from the one in the core in one way: the buffer will be always copied back, even when the transfer failed. It looks like it is expected that the sanity check for a correct CRC and header will bail out later. Use the block read from the I2C core and propagate a potential errno further to the sanity check. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> --- Note: we could now make the error checking even stronger by checking if the number of received bytes is I2C_SMBUS_BLOCK_MAX. But to avoid regressions, I kept the logic as is, i.e. only check for errno. drivers/media/i2c/adv7511-v4l2.c | 40 +++++++++++--------------------- 1 file changed, 14 insertions(+), 26 deletions(-)