From: Bitan Biswas <bbiswas@nvidia.com>
To: Dmitry Osipenko <digetx@gmail.com>,
Laxman Dewangan <ldewangan@nvidia.com>,
Thierry Reding <treding@nvidia.com>,
Jonathan Hunter <jonathanh@nvidia.com>,
<linux-i2c@vger.kernel.org>, <linux-tegra@vger.kernel.org>,
<linux-kernel@vger.kernel.org>, Peter Rosin <peda@axentia.se>,
Wolfram Sang <wsa@the-dreams.de>
Cc: Shardar Mohammed <smohammed@nvidia.com>,
Sowjanya Komatineni <skomatineni@nvidia.com>,
Mantravadi Karthik <mkarthik@nvidia.com>
Subject: Re: [PATCH V3 6/6] i2c: tegra: remove BUG, BUG_ON
Date: Mon, 10 Jun 2019 03:58:16 -0700 [thread overview]
Message-ID: <4f151ae7-423b-1938-39a8-7ec4ae3632df@nvidia.com> (raw)
In-Reply-To: <89190a56-bc79-7c07-9b21-ebdfb532df30@gmail.com>
On 6/10/19 3:30 AM, Dmitry Osipenko wrote:
> 10.06.2019 8:08, Bitan Biswas пишет:
>> Remove redundant BUG_ON calls or replace with WARN_ON_ONCE
>> as needed. Replace BUG() with error handling code.
>> Define I2C_ERR_UNEXPECTED_STATUS for error handling.
>>
>> Signed-off-by: Bitan Biswas <bbiswas@nvidia.com>
>> ---
>> drivers/i2c/busses/i2c-tegra.c | 18 +++++++++++-------
>> 1 file changed, 11 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-tegra.c b/drivers/i2c/busses/i2c-tegra.c
>> index 4dfb4c1..d9e99b4 100644
>> --- a/drivers/i2c/busses/i2c-tegra.c
>> +++ b/drivers/i2c/busses/i2c-tegra.c
>> @@ -73,6 +73,7 @@
>> #define I2C_ERR_NO_ACK BIT(0)
>> #define I2C_ERR_ARBITRATION_LOST BIT(1)
>> #define I2C_ERR_UNKNOWN_INTERRUPT BIT(2)
>> +#define I2C_ERR_UNEXPECTED_STATUS BIT(3)
>>
>> #define PACKET_HEADER0_HEADER_SIZE_SHIFT 28
>> #define PACKET_HEADER0_PACKET_ID_SHIFT 16
>> @@ -515,7 +516,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
>> * prevent overwriting past the end of buf
>> */
>> if (rx_fifo_avail > 0 && buf_remaining > 0) {
>> - BUG_ON(buf_remaining > 3);
>> val = i2c_readl(i2c_dev, I2C_RX_FIFO);
>> val = cpu_to_le32(val);
>> memcpy(buf, &val, buf_remaining);
>> @@ -523,7 +523,6 @@ static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
>> rx_fifo_avail--;
>> }
>>
>> - BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
>> i2c_dev->msg_buf_remaining = buf_remaining;
>> i2c_dev->msg_buf = buf;
>>
>> @@ -581,7 +580,6 @@ static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
>> * boundary and fault.
>> */
>> if (tx_fifo_avail > 0 && buf_remaining > 0) {
>> - BUG_ON(buf_remaining > 3);
>> memcpy(&val, buf, buf_remaining);
>> val = le32_to_cpu(val);
>>
>> @@ -847,10 +845,13 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
>>
>> if (!i2c_dev->is_curr_dma_xfer) {
>> if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
>> - if (i2c_dev->msg_buf_remaining)
>> + if (i2c_dev->msg_buf_remaining) {
>> tegra_i2c_empty_rx_fifo(i2c_dev);
>> - else
>> - BUG();
>> + } else {
>> + dev_err(i2c_dev->dev, "unexpected rx data request\n");
>> + i2c_dev->msg_err |= I2C_ERR_UNEXPECTED_STATUS;
>> + goto err;
>> + }
>> }
>>
>> if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
>> @@ -876,7 +877,10 @@ static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
>> if (status & I2C_INT_PACKET_XFER_COMPLETE) {
>> if (i2c_dev->is_curr_dma_xfer)
>> i2c_dev->msg_buf_remaining = 0;
>> - BUG_ON(i2c_dev->msg_buf_remaining);
>> + if (WARN_ON_ONCE(i2c_dev->msg_buf_remaining)) {
>> + i2c_dev->msg_err |= I2C_ERR_UNKNOWN_INTERRUPT;
>> + goto err;
>> + }
>> complete(&i2c_dev->msg_complete);
>> }
>> goto done;
>>
>
> It looks nearly ideal now, although there is still one thing that could
> be improved. We're going to print a error message in a case of RX and
> spew a warning on a similar case of TX, this makes code inconsistent.
> Let's switch to either a error message or just a warning in both places.
>
Agree. I shall share the updated patch.
-Thanks,
Bitan
prev parent reply other threads:[~2019-06-10 10:58 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-10 5:08 [PATCH V3 1/6] i2c: tegra: clean up macros Bitan Biswas
2019-06-10 5:08 ` [PATCH V3 2/6] i2c: tegra: remove unnecessary variable init Bitan Biswas
2019-06-10 5:08 ` [PATCH V3 3/6] i2c: tegra: fix alignment and spacing violations Bitan Biswas
2019-06-10 5:08 ` [PATCH V3 4/6] i2c: tegra: add spinlock definition comment Bitan Biswas
2019-06-10 5:08 ` [PATCH V3 5/6] i2c: tegra: fix msleep warning Bitan Biswas
2019-06-10 5:08 ` [PATCH V3 6/6] i2c: tegra: remove BUG, BUG_ON Bitan Biswas
2019-06-10 10:30 ` Dmitry Osipenko
2019-06-10 10:58 ` Bitan Biswas [this message]
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