Re: [PATCH v3 3/7] mtd: spi-nor: add the framework for SPI NOR

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Tuesday 17 December 2013 08:26 AM, Huang Shijie wrote:
On Tue, Dec 17, 2013 at 12:11:58AM +0530, Sourav Poddar wrote:
+static int spi_nor_read(struct mtd_info *mtd, loff_t from, size_t len,
+			size_t *retlen, u_char *buf)
+{
+	struct spi_nor *nor = mtd_to_spi_nor(mtd);
+	int ret;
+
+	dev_dbg(nor->dev, "from 0x%08x, len %zd\n", (u32)from, len);
+
+	ret = spi_nor_lock_and_prep(nor, SPI_NOR_OPS_READ);
+	if (ret)
+		return ret;
+
+	/* Wait till previous write/erase is done. */
+	ret = wait_till_ready(nor);
+	if (ret)
+		goto read_err;
+
Can you shift "wait_till_ready" above spi_nor_lock_and_prep?
One usecase for asking for above change is that I am planning to
use this _prep api for switching to memory mapped mode for read and once
I am switched to mmap mode, read_sr calls in wait_till_ready will not
work for me.

you can implement your own wait_till_ready here.
I think no point doing this, since it does the same function for me.
Only we have grabbed the lock, then we can do the transactions with the NOR.

We can not call the wait_till_ready before we grab the lock, it is wrong.


If you really can not implement your own wait_till_ready, the final solution
is removing the wait_till_ready in this function, and add the wait_till_ready
in the nor->read() hook.


Yes, this can be done. So, that if you want to do memcpy do it before this
condition is hit.

thanks
Huang Shijie



--
To unsubscribe from this list: send the line "unsubscribe linux-doc" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux FS]     [Yosemite Forum]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Video 4 Linux]     [Device Mapper]     [Linux Resources]

  Powered by Linux