From owner-svn-src-all@freebsd.org Sat Mar 2 20:58:52 2019 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 46C93150EE39; Sat, 2 Mar 2019 20:58:52 +0000 (UTC) (envelope-from ian@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id DF87382E85; Sat, 2 Mar 2019 20:58:51 +0000 (UTC) (envelope-from ian@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id CF0C7A27A; Sat, 2 Mar 2019 20:58:51 +0000 (UTC) (envelope-from ian@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x22KwpFK017775; Sat, 2 Mar 2019 20:58:51 GMT (envelope-from ian@FreeBSD.org) Received: (from ian@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x22Kwp5u017774; Sat, 2 Mar 2019 20:58:51 GMT (envelope-from ian@FreeBSD.org) Message-Id: <201903022058.x22Kwp5u017774@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: ian set sender to ian@FreeBSD.org using -f From: Ian Lepore Date: Sat, 2 Mar 2019 20:58:51 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r344728 - head/sys/dev/flash X-SVN-Group: head X-SVN-Commit-Author: ian X-SVN-Commit-Paths: head/sys/dev/flash X-SVN-Commit-Revision: 344728 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: DF87382E85 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.94 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_LONG(-1.00)[-0.999,0]; NEURAL_HAM_SHORT(-0.94)[-0.940,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 02 Mar 2019 20:58:52 -0000 Author: ian Date: Sat Mar 2 20:58:51 2019 New Revision: 344728 URL: https://svnweb.freebsd.org/changeset/base/344728 Log: Bugfix: use a dummy buffer for the inactive side of a transfer. This is especially important for writes. SPI is inherently a bidirectional bus; you receive data (even if it's garbage) while writing. We should not receive that data into the same buffer we're writing to the device. When reading it doesn't matter what we send to the device, but using the dummy buffer for that as well is pleasingly symmetrical. Modified: head/sys/dev/flash/at45d.c Modified: head/sys/dev/flash/at45d.c ============================================================================== --- head/sys/dev/flash/at45d.c Sat Mar 2 16:28:29 2019 (r344727) +++ head/sys/dev/flash/at45d.c Sat Mar 2 20:58:51 2019 (r344728) @@ -95,6 +95,7 @@ struct at45d_softc uint16_t pagecount; uint16_t pageoffset; uint16_t pagesize; + void *dummybuf; }; #define TSTATE_STOPPED 0 @@ -285,6 +286,7 @@ at45d_detach(device_t dev) if (err == 0 && sc->taskstate == TSTATE_STOPPED) { disk_destroy(sc->disk); bioq_flush(&sc->bio_queue, NULL, ENXIO); + free(sc->dummybuf, M_DEVBUF); AT45D_LOCK_DESTROY(sc); } return (err); @@ -334,6 +336,8 @@ at45d_delayed_attach(void *xsc) pagesize = ident->pagesize; sc->pagesize = pagesize; + sc->dummybuf = malloc(pagesize, M_DEVBUF, M_WAITOK | M_ZERO); + sc->disk = disk_alloc(); sc->disk->d_open = at45d_open; sc->disk->d_close = at45d_close; @@ -444,11 +448,13 @@ at45d_task(void *arg) case BIO_READ: txBuf[0] = CONTINUOUS_ARRAY_READ; cmd.tx_cmd_sz = cmd.rx_cmd_sz = 8; - cmd.tx_data = cmd.rx_data = buf; + cmd.tx_data = sc->dummybuf; + cmd.rx_data = buf; break; case BIO_WRITE: cmd.tx_cmd_sz = cmd.rx_cmd_sz = 4; - cmd.tx_data = cmd.rx_data = buf; + cmd.tx_data = buf; + cmd.rx_data = sc->dummybuf; if (resid + offset > sc->pagesize) len = sc->pagesize - offset; break; @@ -524,7 +530,10 @@ at45d_task(void *arg) len = sc->pagesize; else len = resid; - cmd.tx_data = cmd.rx_data = buf; + if (bp->bio_cmd == BIO_READ) + cmd.rx_data = buf; + else + cmd.tx_data = buf; } out: if (berr != 0) {