From: Wolfram Sang <wsa@kernel.org>
To: Chris Packham <chris.packham@alliedtelesis.co.nz>
Cc: rjui@broadcom.com, sbranden@broadcom.com,
bcm-kernel-feedback-list@broadcom.com, linux-i2c@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org,
Richard Laing <richard.laing@alliedtelesis.co.nz>
Subject: Re: [PATCH v3] i2c: bcm-iproc: Add i2c recovery support
Date: Mon, 29 Nov 2021 20:01:11 +0100 [thread overview]
Message-ID: <YaUjd747t94Ge/VA@kunai> (raw)
In-Reply-To: <20210603052515.11178-1-chris.packham@alliedtelesis.co.nz>
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Hi Chris,
sorry for the long delay.
All looks good except for this:
> @@ -806,6 +954,7 @@ static int bcm_iproc_i2c_xfer_wait(struct bcm_iproc_i2c_dev *iproc_i2c,
> /* flush both TX/RX FIFOs */
> val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT);
> iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
> + iproc_i2c_lockup_recover(iproc_i2c);
> return -ETIMEDOUT;
> }
>
> @@ -814,6 +963,7 @@ static int bcm_iproc_i2c_xfer_wait(struct bcm_iproc_i2c_dev *iproc_i2c,
> /* flush both TX/RX FIFOs */
> val = BIT(M_FIFO_RX_FLUSH_SHIFT) | BIT(M_FIFO_TX_FLUSH_SHIFT);
> iproc_i2c_wr_reg(iproc_i2c, M_FIFO_CTRL_OFFSET, val);
> + iproc_i2c_lockup_recover(iproc_i2c);
> return ret;
> }
I2C specs suggest recovery at the beginning of a transfer when SDA is
detected low. Not at the end of a transfer.
Happy hacking,
Wolfram
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prev parent reply other threads:[~2021-11-29 19:03 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-03 5:25 [PATCH v3] i2c: bcm-iproc: Add i2c recovery support Chris Packham
2021-06-03 17:06 ` Ray Jui
2021-11-29 19:01 ` Wolfram Sang [this message]
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