From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Ujfalusi Subject: Re: [PATCH v4 20/25] dmaengine: edma: Simplify the interrupt handling Date: Wed, 14 Oct 2015 14:16:06 +0300 Message-ID: <561E3976.3050100@ti.com> References: <1443088932-21731-1-git-send-email-peter.ujfalusi@ti.com> <1443088932-21731-21-git-send-email-peter.ujfalusi@ti.com> <20151014102039.GK27370@localhost> <561E3883.6000705@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <561E3883.6000705@ti.com> Sender: linux-kernel-owner@vger.kernel.org To: Vinod Koul Cc: nsekhar@ti.com, linux@arm.linux.org.uk, olof@lixom.net, arnd@arndb.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-omap@vger.kernel.org, dmaengine@vger.kernel.org List-Id: linux-omap@vger.kernel.org On 10/14/2015 02:12 PM, Peter Ujfalusi wrote: >>> + } else if (edma_read(ecc, EDMA_QEMR)) { >>> + dev_dbg(ecc->dev, "QEMR %02x\n", >>> + edma_read(ecc, EDMA_QEMR)); >>> + for (i =3D 0; i < 8; i++) { >>> + if (edma_read(ecc, EDMA_QEMR) & BIT(i)) { >>> + /* Clear the corresponding IPR bits */ >>> + edma_write(ecc, EDMA_QEMCR, BIT(i)); >>> + edma_shadow0_write(ecc, SH_QSECR, >>> + BIT(i)); >>> + >>> + /* NOTE: not reported!! */ >> >> what does this mean? >=20 > For QEMR and CCERR registers the Linux driver only acks the event, bu= t do not > do anything. > In Linux we are not using the qDMA of the eDMA3 and there is not much= we can > do when the CCERR happens. > Hrm, probably moving the CCERR print to dev_err() might be useful, bu= t again I > have not seen this happen. But if it does, we need to come up with so= mething > to avoid it. Basically repartition the use of Transfer Controllers, b= ut this > can not be done with this stack. An upcoming series will give us ways= to fine > tune the use of TCs. In the interrupt handler simplification patch I move the CCERR to dev_w= arn() so I leave it like this for this patch - as the function has been just = moved down in the code to be able to call the actual handler of the events. --=20 P=E9ter