[PATCH 2/5] i2c: mv64xxx: refactor message start to ensure proper initialization
Gregory CLEMENT
gregory.clement at free-electrons.com
Fri Feb 14 06:39:02 EST 2014
On 13/02/2014 21:36, Wolfram Sang wrote:
> Because the offload mechanism can fall back to a standard transfer,
> having two seperate initialization states is unfortunate. Let's just
> have one state which does things consistently. This fixes a bug where
> some preparation was missing when the fallback happened. And it makes
> the code much easier to follow.
>
> Signed-off-by: Wolfram Sang <wsa at the-dreams.de>
Tested-by: Gregory CLEMENT <gregory.clement at free-electrons.com>
With this one the bug we observed was fixed.
Thanks,
Gregory
> ---
> drivers/i2c/busses/i2c-mv64xxx.c | 27 ++++++++++-----------------
> 1 file changed, 10 insertions(+), 17 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
> index ba64978..d52d849 100644
> --- a/drivers/i2c/busses/i2c-mv64xxx.c
> +++ b/drivers/i2c/busses/i2c-mv64xxx.c
> @@ -97,7 +97,6 @@ enum {
> enum {
> MV64XXX_I2C_ACTION_INVALID,
> MV64XXX_I2C_ACTION_CONTINUE,
> - MV64XXX_I2C_ACTION_OFFLOAD_SEND_START,
> MV64XXX_I2C_ACTION_SEND_START,
> MV64XXX_I2C_ACTION_SEND_RESTART,
> MV64XXX_I2C_ACTION_OFFLOAD_RESTART,
> @@ -460,15 +459,14 @@ mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
> drv_data->reg_base + drv_data->reg_offsets.control);
> break;
>
> - case MV64XXX_I2C_ACTION_OFFLOAD_SEND_START:
> - if (!mv64xxx_i2c_offload_msg(drv_data))
> - break;
> - else
> - drv_data->action = MV64XXX_I2C_ACTION_SEND_START;
> - /* FALLTHRU */
> case MV64XXX_I2C_ACTION_SEND_START:
> - writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START,
> - drv_data->reg_base + drv_data->reg_offsets.control);
> + /* Can we offload this msg ? */
> + if (mv64xxx_i2c_offload_msg(drv_data) < 0) {
> + /* No, switch to standard path */
> + mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs);
> + writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START,
> + drv_data->reg_base + drv_data->reg_offsets.control);
> + }
> break;
>
> case MV64XXX_I2C_ACTION_SEND_ADDR_1:
> @@ -627,15 +625,10 @@ mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg,
> unsigned long flags;
>
> spin_lock_irqsave(&drv_data->lock, flags);
> - if (drv_data->offload_enabled) {
> - drv_data->action = MV64XXX_I2C_ACTION_OFFLOAD_SEND_START;
> - drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
> - } else {
> - mv64xxx_i2c_prepare_for_io(drv_data, msg);
>
> - drv_data->action = MV64XXX_I2C_ACTION_SEND_START;
> - drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
> - }
> + drv_data->action = MV64XXX_I2C_ACTION_SEND_START;
> + drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
> +
> drv_data->send_stop = is_last;
> drv_data->block = 1;
> mv64xxx_i2c_do_action(drv_data);
>
--
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
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