diff options
author | Rajkumar Subbiah <rsubbia@codeaurora.org> | 2017-02-17 15:05:08 -0500 |
---|---|---|
committer | Gerrit - the friendly Code Review server <code-review@localhost> | 2017-03-23 11:51:05 -0700 |
commit | d4b4dcba33e7dcc38b6080d75f799568212b9222 (patch) | |
tree | 021d4b08bbbaf131a608bbfee4e727f0931fead7 | |
parent | e4b8f93b8442e0fbc65bb56c0f8bd1d9d1cb3288 (diff) |
msm: mdss: handle synchronization issues during DSI debugfs read/write
Handle race condition during read/write operations to DSI debugfs nodes
related to DSI panel ON/OFF commands.
Change-Id: I29c4ad74bf21d4cb5362565e902a682fe7263147
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>
Signed-off-by: Rajkumar Subbiah <rsubbia@codeaurora.org>
-rw-r--r-- | drivers/video/fbdev/msm/mdss_dsi.c | 19 |
1 files changed, 18 insertions, 1 deletions
diff --git a/drivers/video/fbdev/msm/mdss_dsi.c b/drivers/video/fbdev/msm/mdss_dsi.c index c66d9f3b3a65..4aa14422899f 100644 --- a/drivers/video/fbdev/msm/mdss_dsi.c +++ b/drivers/video/fbdev/msm/mdss_dsi.c @@ -629,6 +629,7 @@ struct buf_data { char *string_buf; /* cmd buf as string, 3 bytes per number */ int sblen; /* string buffer length */ int sync_flag; + struct mutex dbg_mutex; /* mutex to synchronize read/write/flush */ }; struct mdss_dsi_debugfs_info { @@ -718,6 +719,7 @@ static ssize_t mdss_dsi_cmd_read(struct file *file, char __user *buf, char *bp; ssize_t ret = 0; + mutex_lock(&pcmds->dbg_mutex); if (*ppos == 0) { kfree(pcmds->string_buf); pcmds->string_buf = NULL; @@ -736,6 +738,7 @@ static ssize_t mdss_dsi_cmd_read(struct file *file, char __user *buf, buffer = kmalloc(bsize, GFP_KERNEL); if (!buffer) { pr_err("%s: Failed to allocate memory\n", __func__); + mutex_unlock(&pcmds->dbg_mutex); return -ENOMEM; } @@ -771,10 +774,12 @@ static ssize_t mdss_dsi_cmd_read(struct file *file, char __user *buf, kfree(pcmds->string_buf); pcmds->string_buf = NULL; pcmds->sblen = 0; + mutex_unlock(&pcmds->dbg_mutex); return 0; /* the end */ } ret = simple_read_from_buffer(buf, count, ppos, pcmds->string_buf, pcmds->sblen); + mutex_unlock(&pcmds->dbg_mutex); return ret; } @@ -786,6 +791,7 @@ static ssize_t mdss_dsi_cmd_write(struct file *file, const char __user *p, int blen = 0; char *string_buf; + mutex_lock(&pcmds->dbg_mutex); if (*ppos == 0) { kfree(pcmds->string_buf); pcmds->string_buf = NULL; @@ -797,6 +803,7 @@ static ssize_t mdss_dsi_cmd_write(struct file *file, const char __user *p, string_buf = krealloc(pcmds->string_buf, blen + 1, GFP_KERNEL); if (!string_buf) { pr_err("%s: Failed to allocate memory\n", __func__); + mutex_unlock(&pcmds->dbg_mutex); return -ENOMEM; } @@ -806,6 +813,7 @@ static ssize_t mdss_dsi_cmd_write(struct file *file, const char __user *p, string_buf[blen] = '\0'; pcmds->string_buf = string_buf; pcmds->sblen = blen; + mutex_unlock(&pcmds->dbg_mutex); return ret; } @@ -816,8 +824,12 @@ static int mdss_dsi_cmd_flush(struct file *file, fl_owner_t id) char *buf, *bufp, *bp; struct dsi_ctrl_hdr *dchdr; - if (!pcmds->string_buf) + mutex_lock(&pcmds->dbg_mutex); + + if (!pcmds->string_buf) { + mutex_unlock(&pcmds->dbg_mutex); return 0; + } /* * Allocate memory for command buffer @@ -830,6 +842,7 @@ static int mdss_dsi_cmd_flush(struct file *file, fl_owner_t id) kfree(pcmds->string_buf); pcmds->string_buf = NULL; pcmds->sblen = 0; + mutex_unlock(&pcmds->dbg_mutex); return -ENOMEM; } @@ -854,6 +867,7 @@ static int mdss_dsi_cmd_flush(struct file *file, fl_owner_t id) pr_err("%s: dtsi cmd=%x error, len=%d\n", __func__, dchdr->dtype, dchdr->dlen); kfree(buf); + mutex_unlock(&pcmds->dbg_mutex); return -EINVAL; } bp += sizeof(*dchdr); @@ -865,6 +879,7 @@ static int mdss_dsi_cmd_flush(struct file *file, fl_owner_t id) pr_err("%s: dcs_cmd=%x len=%d error!\n", __func__, bp[0], len); kfree(buf); + mutex_unlock(&pcmds->dbg_mutex); return -EINVAL; } @@ -877,6 +892,7 @@ static int mdss_dsi_cmd_flush(struct file *file, fl_owner_t id) pcmds->buf = buf; pcmds->blen = blen; } + mutex_unlock(&pcmds->dbg_mutex); return 0; } @@ -891,6 +907,7 @@ struct dentry *dsi_debugfs_create_dcs_cmd(const char *name, umode_t mode, struct dentry *parent, struct buf_data *cmd, struct dsi_panel_cmds ctrl_cmds) { + mutex_init(&cmd->dbg_mutex); cmd->buf = ctrl_cmds.buf; cmd->blen = ctrl_cmds.blen; cmd->string_buf = NULL; |