From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexander Stein Subject: Re: [PATCH v2] spi-fsl-dspi: Fix CTAR Register access Date: Thu, 10 Dec 2015 08:15:14 +0100 Message-ID: <2295258.Vc5Dp4nsCT@ws-stein> References: <1449726930-7378-1-git-send-email-bhuvanchandra.dv@toradex.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: Bhuvanchandra DV , broonie@kernel.org, stefan@agner.ch, linux-spi@vger.kernel.org To: linux-kernel@vger.kernel.org Return-path: In-Reply-To: <1449726930-7378-1-git-send-email-bhuvanchandra.dv@toradex.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-spi.vger.kernel.org On Thursday 10 December 2015 11:25:30, Bhuvanchandra DV wrote: > DSPI instances in Vybrid have a different amount of chip selects > and CTARs (Clock and transfer Attributes Register). In case of > DSPI1 we only have 2 CTAR registers and 4 CS. In present driver > implementation CTAR offset is derived from CS instance which will > lead to out of bound access if chip select instance is greater than > CTAR register instance, hence use single CTAR0 register for all CS > instances. Since we write the CTAR register anyway before each access, > there is no value in using the additional CTAR registers. Also one > should not program a value in CTAS for a CTAR register that is not > present, hence configure CTAS to use CTAR0. Shouldn't the information put into struct fsl_dspi_devtype_data how much CTAR and CS the actual implementation has available? E.g. LS1021A has 6 CS and 4 CTAR Best regards, Alexander -- ----- Please note our closure period for Christmas vacation and turn of the year We are closed from 21st December 2015 to 3rd January 2016 ----- Dipl.-Inf. Alexander Stein SYS TEC electronic GmbH alexander.stein@systec-electronic.com Legal and Commercial Address: Am Windrad 2 08468 Heinsdorfergrund Germany Office: +49 (0) 3765 38600-0 Fax: +49 (0) 3765 38600-4100 Managing Directors: Director Technology/CEO: Dipl.-Phys. Siegmar Schmidt; Director Commercial Affairs/COO: Dipl. Ing. (FH) Armin von Collrepp Commercial Registry: Amtsgericht Chemnitz, HRB 28082; USt.-Id Nr. DE150534010