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 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-Id: <20190123212046.13020-1-opensource@vdorst.com> Date: Wed, 23 Jan 2019 22:20:46 +0100 From: René van Dorst <opensource@...rst.com> To: Andrew Lunn <andrew@...n.ch>, Florian Fainelli <f.fainelli@...il.com>, Heiner Kallweit <hkallweit1@...il.com>, "David S. Miller" <davem@...emloft.net>, netdev@...r.kernel.org Cc: René van Dorst <opensource@...rst.com> Subject: [PATCH] sfp: sfp_read: split-up request when hw rx buffer is too small. Without this patch sfp code retries to read the full struct sfp_eeprom_id id out of the SFP eeprom. Sizeof(id) is 96 bytes. My i2c hardware, Mediatek mt7621, has a rx buffer of 64 bytes. So sfp_read gets -NOSUPPORTED back on his turn return -EAGAIN. Same issue is with the SFP_EXT_STATUS data which is 92 bytes. By split-up the request in multiple smaller requests with a max size of i2c max_read_len, we can readout the SFP module successfully. Tested with MT7621 and two Fiberstore modules SFP-GB-GE-T and SFP-GE-BX. Signed-off-by: René van Dorst <opensource@...rst.com> --- drivers/net/phy/sfp.c | 23 ++++++++++++++++++++++- 1 file changed, 22 insertions(+), 1 deletion(-) diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c index fd8bb998ae52..1352a19571cd 100644 --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -367,7 +367,28 @@ static void sfp_set_state(struct sfp *sfp, unsigned int state) static int sfp_read(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len) { - return sfp->read(sfp, a2, addr, buf, len); + const struct i2c_adapter_quirks *q = sfp->i2c->quirks; + int ret; + size_t rx_bytes = 0; + + /* Many i2c hw have limited rx buffers, split-up request when needed. */ + while ((q->max_read_len) && (len > q->max_read_len)) { + ret = sfp->read(sfp, a2, addr, buf, q->max_read_len); + if (ret < 0) + return ret; + rx_bytes += ret; + addr += q->max_read_len; + buf += q->max_read_len; + len -= q->max_read_len; + } + + ret = sfp->read(sfp, a2, addr, buf, len); + if (ret < 0) + return ret; + + rx_bytes += ret; + + return rx_bytes; } static int sfp_write(struct sfp *sfp, bool a2, u8 addr, void *buf, size_t len) -- 2.19.1
Powered by blists - more mailing lists