Re: [U-Boot] [Patch V5 2/4] spi: fsl_qspi: Fix qspi_op_rdid memcpy issue

22 Jan 2016

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-----Original Message-----
From: Scott Wood
Sent: Friday, January 22, 2016 3:30 AM
To: Qianyu Gong qianyu.gong@nxp.com; u-boot@lists.denx.de;
R58495@freescale.com
Cc: Mingkai.Hu@freescale.com; jteki@openedev.com; B48286@freescale.com;
Shaohui.Xie@freescale.com; Wenbin.Song@freescale.com; Scott Wood
oss@buserror.net; Gong Qianyu Qianyu.Gong@freescale.com
Subject: Re: [Patch V5 2/4] spi: fsl_qspi: Fix qspi_op_rdid memcpy issue
On 01/20/2016 09:43 PM, Gong Qianyu wrote:
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From: Gong Qianyu Qianyu.Gong@freescale.com
In current driver everytime we memcpy 4 bytes to the dest memory
regardless of the remaining length.
This patch adds checking the remaining length before memcpy.
If the length is shorter than 4 bytes, memcpy the actual length of
data to the dest memory.
Signed-off-by: Gong Qianyu Qianyu.Gong@freescale.com
V2-V5:

No change.

drivers/spi/fsl_qspi.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/fsl_qspi.c b/drivers/spi/fsl_qspi.c index
38e5900..f178857 100644
--- a/drivers/spi/fsl_qspi.c
+++ b/drivers/spi/fsl_qspi.c
@@ -500,7 +500,10 @@ static void qspi_op_rdid(struct fsl_qspi_priv *priv, u32
*rxbuf, u32 len)
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if (rbsr_reg & QSPI_RBSR_RDBFL_MASK) {
	data = qspi_read32(priv->flags, &regs->rbdr[i]);
	data = qspi_endian_xchg(data);


	memcpy(rxbuf, &data, 4);




	if (size < 4)


		memcpy(rxbuf, &data, size);


	else


		memcpy(rxbuf, &data, 4);



memcpy(rxbuf, &data, min(size, 4));
...
	rxbuf++;
	size -= 4;
	i++;

size -= 4 even if size was < 4?
-Scott
Yes.. The following is complete code:
i = 0;
        size = len;
        while ((RX_BUFFER_SIZE >= size) && (size > 0)) {
                rbsr_reg = qspi_read32(priv->flags, &regs->rbsr);
                if (rbsr_reg & QSPI_RBSR_RDBFL_MASK) {
                        data = qspi_read32(priv->flags, &regs->rbdr[i]);
                        data = qspi_endian_xchg(data);
                        memcpy(rxbuf, &data, min(size, 4));
                        rxbuf++;
                        size -= 4;
                        i++;
                }
        }
Regards,
Qianyu

    