lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date:   Mon, 15 Apr 2019 14:13:23 +0200
From:   Wolfram Sang <wsa@...-dreams.de>
To:     "Adamski, Krzysztof (Nokia - PL/Wroclaw)" 
        <krzysztof.adamski@...ia.com>
Cc:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-i2c@...r.kernel.org" <linux-i2c@...r.kernel.org>,
        "Sverdlin, Alexander (Nokia - DE/Ulm)" <alexander.sverdlin@...ia.com>
Subject: Re: [PATCH] axxia-i2c: use auto cmd for last message

On Thu, Mar 28, 2019 at 11:19:45AM +0000, Adamski, Krzysztof (Nokia - PL/Wroclaw) wrote:
> Some recent commits to this driver were trying to make sure the TSS
> interrupt is not generated on busy system due to 25ms timer expiring
> between commands. It can still happen, however if STOP command is not
> issued on time at the end of the transmission. If wait_for_completion in
> axxia_i2c_xfer_msg() would not return after 25ms of getting an
> interrupt, TSS will be generated and idev->err_msg will be set to
> -ETIMEDOUT which will be returned from the axxia_i2c_xfer_msg(), even
> though the transfer did actually succeed (STOP is automatically issued
> when TSS triggers).
> 
> Fortunately, apart from already used manual and sequence commands, the
> controller also has so called auto command. It works just like manual
> mode but it but an automatic STOP is issued when either transfer length
> is met or NAK is received from slave device.
> 
> This patch changes the axxia_i2c_xfer_msg() function so that auto
> command is used for last message in transaction letting hardware manage
> issuing STOP. TSS is disabled just after command transferring last
> message finishes. Auto command, just like sequence, ends with SS
> interrupt instead of SNS so handling of both had to be unified.
> 
> The axxia_i2c_stop() is no longer needed as the transfer can only end
> with following conditions:
> - fully successful - then last message was send by AUTO command and STOP
>   was issued automatically
> - NAK received - STOP is issued automatically by controller
> - arbitration lost - STOP should not be issued as we don't control the
>   bus
> - IP interrupt received - this is sent when transfer length is set to 0
>   for auto/sequence command. The check for that is done before START is
>   send so no STOP is required
> - TSS received between commands - STOP is issued by the controller
> 
> Signed-off-by: Krzysztof Adamski <krzysztof.adamski@...ia.com>
> Reviewed-by: Alexander Sverdlin <alexander.sverdlin@...ia.com>

Changed $subject to "i2c: axxia:" and applied to for-next, thanks!


Download attachment "signature.asc" of type "application/pgp-signature" (834 bytes)

Powered by blists - more mailing lists