Re: [PATCH v4 3/3] i2c: qcom-geni: Add bus recovery support for GPI DMA mode

[Mukesh Savaliya <mukesh.savaliya@oss.qualcomm.com>]

On 11/3/2026 2:26 PM, Aniket Randive wrote:
> I2C transfers in GPI DMA mode can fail with -EIO when a target holds
> SDA low, leaving the bus stuck and preventing subsequent transactions.
> The GPI completion callback reports a NACK and a genuine bus error
> alike as -EIO, and the existing recovery path switches the SE to FIFO
> mode which is not valid in GPI DMA mode.
> 
> Add bus recovery support using the I2C_BUS_CLEAR and I2C_STOP_ON_BUS
> opcodes issued via the GPI TX DMA channel. Guard the -EIO recovery
> trigger with a SE_GENI_IOS I2C_BUS_FREE check to skip recovery when both
> SDA and SCL are already released. Extend the recovery callback to dispatch
> through the GPI DMA path when gi2c->gpi_mode is set.
> 
> Use the adapter timeout for GPI recovery commands, and preserve the DMA
> configuration error code when GPI setup fails.
> 
> Stop recovery on a GPI command timeout and report DMA termination
> failures. Do not issue another command or override the timeout with a
> bus-idle result, since DMA cleanup may not have completed successfully.
> 
> Signed-off-by: Aniket Randive <aniket.randive@oss.qualcomm.com>
> ---
Reviewed-by: Mukesh Kumar Savaliya <mukesh.savaliya@oss.qualcomm.com>