Merge "msm: mdss: handle synchronization issues during DSI debugfs read/write" (2a7bbea4) · Commits · e / devices / android_kernel_sony_msm8998

drivers/video/fbdev/msm/mdss_dsi.c

+18 −1

Original line number	Diff line number	Diff line
		@@ -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;