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Violators will be prosecuted; Tue, 4 Apr 2017 22:09:29 -0400 Received: from b01ledav004.gho.pok.ibm.com (b01ledav004.gho.pok.ibm.com [9.57.199.109]) by b01cxnp23032.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v3529TcC36831416; Wed, 5 Apr 2017 02:09:29 GMT Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CA1D9112056; Tue, 4 Apr 2017 22:09:29 -0400 (EDT) Received: from Christophers-MacBook-Pro.local.com (unknown [9.81.217.91]) by b01ledav004.gho.pok.ibm.com (Postfix) with ESMTP id 25D9111204B; Tue, 4 Apr 2017 22:09:19 -0400 (EDT) From: Christopher Bostic To: robh+dt@kernel.org, mark.rutland@arm.com, linux@armlinux.org.uk, rostedt@goodmis.org, mingo@redhat.com, gregkh@linuxfoundation.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v5 17/23] drivers/fsi: Add error handling for slave communication errors Date: Tue, 4 Apr 2017 21:06:01 -0500 X-Mailer: git-send-email 2.10.1 (Apple Git-78) In-Reply-To: <20170405020607.79939-1-cbostic@linux.vnet.ibm.com> References: <20170405020607.79939-1-cbostic@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 17040502-2213-0000-0000-00000181E630 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00006884; HX=3.00000240; KW=3.00000007; PH=3.00000004; SC=3.00000208; SDB=6.00843220; UDB=6.00415443; IPR=6.00621396; BA=6.00005266; NDR=6.00000001; ZLA=6.00000005; ZF=6.00000009; ZB=6.00000000; ZP=6.00000000; ZH=6.00000000; ZU=6.00000002; MB=3.00014914; XFM=3.00000013; UTC=2017-04-05 02:09:33 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 17040502-2214-0000-0000-0000553998C9 Message-Id: <20170405020607.79939-18-cbostic@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2017-04-05_01:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1702020001 definitions=main-1704050018 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20170405_031000_162377_489702CF X-CRM114-Status: GOOD ( 19.58 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Chris Bostic , andrew@aj.id.au, alistair@popple.id.au, linux-kernel@vger.kernel.org, Jeremy Kerr , benh@kernel.crashing.org, joel@jms.id.au MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP From: Jeremy Kerr This change implements error handling in the FSI core, by cleaning up and retrying failed operations, using the SISC, TERM and BREAK facilities. Signed-off-by: Jeremy Kerr Signed-off-by: Chris Bostic --- drivers/fsi/fsi-core.c | 121 ++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 114 insertions(+), 7 deletions(-) diff --git a/drivers/fsi/fsi-core.c b/drivers/fsi/fsi-core.c index 09becec..747d0e3 100644 --- a/drivers/fsi/fsi-core.c +++ b/drivers/fsi/fsi-core.c @@ -44,7 +44,9 @@ /* * FSI slave engine control register offsets */ -#define FSI_SMODE 0x0 /* R/W: Mode register */ +#define FSI_SMODE 0x0 /* R/W: Mode register */ +#define FSI_SISC 0x8 /* R/W: Interrupt condition */ +#define FSI_SSTAT 0x14 /* R : Slave status */ /* * SMODE fields @@ -75,10 +77,14 @@ struct fsi_slave { #define to_fsi_master(d) container_of(d, struct fsi_master, dev) #define to_fsi_slave(d) container_of(d, struct fsi_slave, dev) +static const int slave_retries = 2; +static int discard_errors; + static int fsi_master_read(struct fsi_master *master, int link, uint8_t slave_id, uint32_t addr, void *val, size_t size); static int fsi_master_write(struct fsi_master *master, int link, uint8_t slave_id, uint32_t addr, const void *val, size_t size); +static int fsi_master_break(struct fsi_master *master, int link); /* FSI endpoint-device support */ @@ -180,32 +186,131 @@ static int fsi_slave_calc_addr(struct fsi_slave *slave, uint32_t *addrp, return 0; } +int fsi_slave_report_and_clear_errors(struct fsi_slave *slave) +{ + struct fsi_master *master = slave->master; + uint32_t irq, stat; + int rc, link; + uint8_t id; + + link = slave->link; + id = slave->id; + + rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SISC, + &irq, sizeof(irq)); + if (rc) + return rc; + + rc = fsi_master_read(master, link, id, FSI_SLAVE_BASE + FSI_SSTAT, + &stat, sizeof(stat)); + if (rc) + return rc; + + dev_info(&slave->dev, "status: 0x%08x, sisc: 0x%08x\n", + be32_to_cpu(stat), be32_to_cpu(irq)); + + /* clear interrupts */ + return fsi_master_write(master, link, id, FSI_SLAVE_BASE + FSI_SISC, + &irq, sizeof(irq)); +} + +static int fsi_slave_set_smode(struct fsi_master *master, int link, int id); + +int fsi_slave_handle_error(struct fsi_slave *slave, bool write, uint32_t addr, + size_t size) +{ + struct fsi_master *master = slave->master; + int rc, link; + uint32_t reg; + uint8_t id; + + if (discard_errors) + return -1; + + link = slave->link; + id = slave->id; + + dev_dbg(&slave->dev, "handling error on %s to 0x%08x[%zd]", + write ? "write" : "read", addr, size); + + /* try a simple clear of error conditions, which may fail if we've lost + * communication with the slave + */ + rc = fsi_slave_report_and_clear_errors(slave); + if (!rc) + return 0; + + /* send a TERM and retry */ + if (master->term) { + rc = master->term(master, link, id); + if (!rc) { + rc = fsi_master_read(master, link, id, 0, + ®, sizeof(reg)); + if (!rc) + rc = fsi_slave_report_and_clear_errors(slave); + if (!rc) + return 0; + } + } + + /* getting serious, reset the slave via BREAK */ + rc = fsi_master_break(master, link); + if (rc) + return rc; + + rc = fsi_slave_set_smode(master, link, id); + if (rc) + return rc; + + return fsi_slave_report_and_clear_errors(slave); +} + int fsi_slave_read(struct fsi_slave *slave, uint32_t addr, void *val, size_t size) { uint8_t id = slave->id; - int rc; + int rc, err_rc, i; rc = fsi_slave_calc_addr(slave, &addr, &id); if (rc) return rc; - return fsi_master_read(slave->master, slave->link, id, - addr, val, size); + for (i = 0; i < slave_retries; i++) { + rc = fsi_master_read(slave->master, slave->link, + id, addr, val, size); + if (!rc) + break; + + err_rc = fsi_slave_handle_error(slave, false, addr, size); + if (err_rc) + break; + } + + return rc; } int fsi_slave_write(struct fsi_slave *slave, uint32_t addr, const void *val, size_t size) { uint8_t id = slave->id; - int rc; + int rc, err_rc, i; rc = fsi_slave_calc_addr(slave, &addr, &id); if (rc) return rc; - return fsi_master_write(slave->master, slave->link, id, - addr, val, size); + for (i = 0; i < slave_retries; i++) { + rc = fsi_master_write(slave->master, slave->link, + id, addr, val, size); + if (!rc) + break; + + err_rc = fsi_slave_handle_error(slave, true, addr, size); + if (err_rc) + break; + } + + return rc; } extern int fsi_slave_claim_range(struct fsi_slave *slave, @@ -765,3 +870,5 @@ static void fsi_exit(void) module_init(fsi_init); module_exit(fsi_exit); +module_param(discard_errors, int, 0664); +MODULE_PARM_DESC(discard_errors, "Don't invoke error handling on bus accesses");