On Fri, Oct 27, 2017 at 03:13:43AM +0200, Marcin Wojtas wrote:
> From: David Greeson <dgreeson@cisco.com>
>
> Although the I2C transaction routines were prepared to
> return their status, they were never used. This could
> cause bus lock-up e.g. in case of failing to send a
> slave address, the data transfer was attempted to be
> continued anyway.
>
> This patch fixes faulty behavior by checking transaction
> status and stopping it immediately, once the fail
> is detected. On the occasion fix style around modified
> functions calls.
>
> Contributed-under: TianoCore Contribution Agreement 1.1
> Signed-off-by: David Greeson <dgreeson@cisco.com>
> [Style adjustment and cleanup]
> Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
> ---
> Platform/Marvell/Drivers/I2c/MvI2cDxe/MvI2cDxe.c | 62 +++++++++++++-------
> 1 file changed, 41 insertions(+), 21 deletions(-)
>
> diff --git a/Platform/Marvell/Drivers/I2c/MvI2cDxe/MvI2cDxe.c b/Platform/Marvell/Drivers/I2c/MvI2cDxe/MvI2cDxe.c
> index d85ee0b..b4599d2 100755
> --- a/Platform/Marvell/Drivers/I2c/MvI2cDxe/MvI2cDxe.c
> +++ b/Platform/Marvell/Drivers/I2c/MvI2cDxe/MvI2cDxe.c
> @@ -565,6 +565,7 @@ MvI2cStartRequest (
> UINTN Transmitted;
> I2C_MASTER_CONTEXT *I2cMasterContext = I2C_SC_FROM_MASTER(This);
> EFI_I2C_OPERATION *Operation;
> + EFI_STATUS Status = EFI_SUCCESS;
>
> ASSERT (RequestPacket != NULL);
> ASSERT (I2cMasterContext != NULL);
> @@ -574,33 +575,52 @@ MvI2cStartRequest (
> ReadMode = Operation->Flags & I2C_FLAG_READ;
>
> if (Count == 0) {
> - MvI2cStart ( I2cMasterContext,
> - (SlaveAddress << 1) | ReadMode,
> - I2C_TRANSFER_TIMEOUT
> - );
> + Status = MvI2cStart (I2cMasterContext,
> + (SlaveAddress << 1) | ReadMode,
> + I2C_TRANSFER_TIMEOUT);
> } else if (!(Operation->Flags & I2C_FLAG_NORESTART)) {
> - MvI2cRepeatedStart ( I2cMasterContext,
> - (SlaveAddress << 1) | ReadMode,
> - I2C_TRANSFER_TIMEOUT
> - );
> + Status = MvI2cRepeatedStart (I2cMasterContext,
> + (SlaveAddress << 1) | ReadMode,
> + I2C_TRANSFER_TIMEOUT);
> }
>
> + /* I2C transaction was aborted, so stop further transactions */
> + if (EFI_ERROR (Status)) {
> + MvI2cStop (I2cMasterContext);
> + break;
> + }
> +
> + /*
> + * If sending the slave address was successful,
> + * proceed to read or write section.
> + */
> if (ReadMode) {
> - MvI2cRead ( I2cMasterContext,
> - Operation->Buffer,
> - Operation->LengthInBytes,
> - &Transmitted,
> - Count == 1,
> - I2C_TRANSFER_TIMEOUT
> - );
> + Status = MvI2cRead (I2cMasterContext,
> + Operation->Buffer,
> + Operation->LengthInBytes,
> + &Transmitted,
> + Count == 1,
> + I2C_TRANSFER_TIMEOUT);
> + Operation->LengthInBytes = Transmitted;
> } else {
> - MvI2cWrite ( I2cMasterContext,
> - Operation->Buffer,
> - Operation->LengthInBytes,
> - &Transmitted,
> - I2C_TRANSFER_TIMEOUT
> - );
> + Status = MvI2cWrite (I2cMasterContext,
> + Operation->Buffer,
> + Operation->LengthInBytes,
> + &Transmitted,
> + I2C_TRANSFER_TIMEOUT);
> + Operation->LengthInBytes = Transmitted;
> }
> +
> + /*
> + * The I2C read or write transaction failed.
> + * Stop the I2C transaction.
> + */
> + if (EFI_ERROR (Status)) {
> + MvI2cStop (I2cMasterContext);
> + break;
> + }
> +
> + /* Check if there is any more data to be sent */
> if (Count == RequestPacket->OperationCount - 1) {
> MvI2cStop ( I2cMasterContext );
> }
> --
> 2.7.4
>
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