From: Michal Simek <michal.simek@xilinx.com>
To: Marek Vasut <marex@denx.de>, <linux-i2c@vger.kernel.org>,
Raviteja Narayanam <raviteja.narayanam@xilinx.com>
Cc: Michal Simek <michal.simek@xilinx.com>,
Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>,
Wolfram Sang <wsa@kernel.org>
Subject: Re: [PATCH v2 0/6] i2c: xiic: Fix broken locking
Date: Tue, 24 Aug 2021 08:58:44 +0200 [thread overview]
Message-ID: <ee2f1e22-2069-308d-2a18-c59fd14387ac@xilinx.com> (raw)
In-Reply-To: <20210823214145.295104-1-marex@denx.de>
+ravi
On 8/23/21 11:41 PM, Marek Vasut wrote:
> Booting ZynqMP with XIIC I2C driver shows multitude of race conditions
> in the XIIC driver. This is because locking is completely missing from
> the driver, and there are odd corner cases where the hardware behaves
> strangely.
>
> Most of these races could be triggered easily when booting on SMP
> machines, like the ZynqMP which has up to 4 cores. It is sufficient
> for the interrupt handler to run on another core than xiic_start_xfer
> and the driver fails completely.
>
> This does not add support for long transfers, this only fixes the
> driver to be usable at all instead of being completely broken.
>
> The V2 fixes a few remaining details which cropped up in deployment
> over the last year or so, so I believe the result should be reasonably
> well tested.
>
> Marek Vasut (6):
> i2c: xiic: Fix broken locking on tx_msg
> i2c: xiic: Drop broken interrupt handler
> i2c: xiic: Defer xiic_wakeup() and __xiic_start_xfer() in
> xiic_process()
> i2c: xiic: Switch from waitqueue to completion
> i2c: xiic: Only ever transfer single message
> i2c: xiic: Fix RX IRQ busy check
>
> drivers/i2c/busses/i2c-xiic.c | 161 +++++++++++++++-------------------
> 1 file changed, 69 insertions(+), 92 deletions(-)
>
> Cc: Michal Simek <michal.simek@xilinx.com>
> Cc: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
> Cc: Wolfram Sang <wsa@kernel.org>
>
next prev parent reply other threads:[~2021-08-24 6:58 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-23 21:41 [PATCH v2 0/6] i2c: xiic: Fix broken locking Marek Vasut
2021-08-23 21:41 ` [PATCH v2 1/6] i2c: xiic: Fix broken locking on tx_msg Marek Vasut
2021-08-23 21:41 ` [PATCH v2 2/6] i2c: xiic: Drop broken interrupt handler Marek Vasut
2021-08-23 21:41 ` [PATCH v2 3/6] i2c: xiic: Defer xiic_wakeup() and __xiic_start_xfer() in xiic_process() Marek Vasut
2021-08-23 21:41 ` [PATCH v2 4/6] i2c: xiic: Switch from waitqueue to completion Marek Vasut
2021-08-23 21:41 ` [PATCH v2 5/6] i2c: xiic: Only ever transfer single message Marek Vasut
2021-08-23 21:41 ` [PATCH v2 6/6] i2c: xiic: Fix RX IRQ busy check Marek Vasut
2021-08-24 6:58 ` Michal Simek [this message]
2021-08-27 8:31 ` [PATCH v2 0/6] i2c: xiic: Fix broken locking Raviteja Narayanam
2021-08-27 8:34 ` Michal Simek
2021-09-14 10:29 ` Wolfram Sang
2021-09-14 11:54 ` Michal Simek
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