From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Mavrodiev Date: Thu, 20 Dec 2018 14:41:57 +0200 Subject: [U-Boot] [PATCH 1/1] arm: sunxi: Add NULL pointer check In-Reply-To: References: <20181205122757.14523-1-stefan@olimex.com> <18e25666-911a-8dc6-f8f5-223f1761eafa@olimex.com> <14480b84-da66-885b-38a0-6f414719ee01@olimex.com> <77fb61ff-ff93-586a-4231-d3f1dca0d54a@olimex.com> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 12/20/18 2:38 PM, Jagan Teki wrote: > On Thu, Dec 20, 2018 at 5:38 PM Stefan Mavrodiev wrote: >> >> On 12/20/18 1:54 PM, Jagan Teki wrote: >>> On Thu, Dec 20, 2018 at 4:49 PM Stefan Mavrodiev wrote: >>>> On 12/20/18 12:56 PM, Jagan Teki wrote: >>>>> On Thu, Dec 20, 2018 at 4:18 PM Stefan Mavrodiev wrote: >>>>>> On 12/20/18 12:45 PM, Jagan Teki wrote: >>>>>>> On Thu, Dec 20, 2018 at 3:59 PM Stefan Mavrodiev wrote: >>>>>>>> On 12/20/18 12:14 PM, Jagan Teki wrote: >>>>>>>>> On Fri, Dec 14, 2018 at 3:48 PM Jagan Teki wrote: >>>>>>>>>> On Wed, Dec 5, 2018 at 5:58 PM Stefan Mavrodiev wrote: >>>>>>>>>>> Current driver doesn't check if the destination pointer is NULL. >>>>>>>>>>> This cause the data from the FIFO to be stored inside the internal >>>>>>>>>>> SDRAM ( address 0 ). >>>>>>>>>>> >>>>>>>>>>> The patch add simple check if the destination pointer is NULL. >>>>>>>>>>> >>>>>>>>>>> Signed-off-by: Stefan Mavrodiev >>>>>>>>>>> --- >>>>>>>>>>> drivers/spi/sun4i_spi.c | 3 ++- >>>>>>>>>>> 1 file changed, 2 insertions(+), 1 deletion(-) >>>>>>>>>>> >>>>>>>>>>> diff --git a/drivers/spi/sun4i_spi.c b/drivers/spi/sun4i_spi.c >>>>>>>>>>> index b86b5a00ad..38cc743c61 100644 >>>>>>>>>>> --- a/drivers/spi/sun4i_spi.c >>>>>>>>>>> +++ b/drivers/spi/sun4i_spi.c >>>>>>>>>>> @@ -129,7 +129,8 @@ static inline void sun4i_spi_drain_fifo(struct sun4i_spi_priv *priv, int len) >>>>>>>>>>> >>>>>>>>>>> while (len--) { >>>>>>>>>>> byte = readb(&priv->regs->rxdata); >>>>>>>>>>> - *priv->rx_buf++ = byte; >>>>>>>>>>> + if (priv->rx_buf) >>>>>>>>>>> + *priv->rx_buf++ = byte; >>>>>>>>>> Acked-by: Jagan Teki >>>>>>>>>> >>>>>>>>>> But, have you tested how much data in the fifo before drained? It's >>>>>>>>>> better we can get the available data before reading via fifo_sta >>>>>>>> I don't understand what's the point of doing this? >>>>>>> Didn't get? don't you understand what I'm saying or it not require >>>>>>> from point of you? >>>>>> Maybe I don't understand correctly what you're saying. >>>>> You comment now and previous mail doesn't match. better be specific. >>>>> >>>>> For draining fifo. >>>>> We can find how much data available before reading from fifo and >>>>> assign to local rx. >>>>> >>>>> static inline void sun4i_spi_drain_fifo(struct sun4i_spi_priv *priv, int len) >>>>> { >>>>> u32 reg, cnt >>>>> u8 byte; >>>>> >>>>> /* See how much data is available */ >>>>> reg = readl(&priv->regs->fifo_sta); >>>>> reg &= SUN4I_FIFO_STA_RF_CNT_MASK; >>>>> cnt = reg >> SUN4I_FIFO_STA_RF_CNT_BITS; >>>>> >>>>> if (len > cnt) >>>>> len = cnt; >>>>> >>>>> while (len--) { >>>>> byte = readb(&priv->regs->rxdata); >>>>> *priv->rx_buf++ = byte; >>>>> } >>>>> } >>>>> >>>>> This can be perfect drain fifo, and this is what I'm trying to test >>>>> you with existing code and after your patch and verify whether all the >>>>> data perfectly drain or not before and after. >>>>> >>>>> Hope you understand, this time. >>>> Hope I understood this time... >>>> >>>> >>>> I've made some modification to sun4i_spi_xfer: >>>> >>>> static int sun4i_spi_xfer(struct udevice *dev, unsigned int bitlen, >>>> const void *dout, void *din, unsigned long flags) >>>> { >>>> struct udevice *bus = dev->parent; >>>> struct sun4i_spi_priv *priv = dev_get_priv(bus); >>>> struct dm_spi_slave_platdata *slave_plat = >>>> dev_get_parent_platdata(dev); >>>> >>>> u32 len = bitlen / 8; >>>> u32 reg, cnt; >>>> u8 nbytes; >>>> int ret; >>>> >>>> priv->tx_buf = dout; >>>> priv->rx_buf = din; >>>> >>>> if (bitlen % 8) { >>>> debug("%s: non byte-aligned SPI transfer.\n", __func__); >>>> return -ENAVAIL; >>>> } >>>> >>>> if (flags & SPI_XFER_BEGIN) >>>> sun4i_spi_set_cs(bus, slave_plat->cs, true); >>>> >>>> reg = readl(&priv->regs->ctl); >>>> >>>> /* Reset FIFOs */ >>>> writel(reg | SUN4I_CTL_RF_RST | SUN4I_CTL_TF_RST, &priv->regs->ctl); >>>> >>>> while (len) { >>>> /* Setup the transfer now... */ >>>> nbytes = min(len, (u32)(SUN4I_FIFO_DEPTH - 1)); >>>> >>>> if (!priv->rx_buf) >>>> printf("%s: Sending %d bytes, ", __func__, nbytes); >>>> >>>> /* Setup the counters */ >>>> writel(SUN4I_BURST_CNT(nbytes), &priv->regs->bc); >>>> writel(SUN4I_XMIT_CNT(nbytes), &priv->regs->tc); >>>> >>>> /* Fill the TX FIFO */ >>>> sun4i_spi_fill_fifo(priv, nbytes); >>>> >>>> /* Start the transfer */ >>>> reg = readl(&priv->regs->ctl); >>>> writel(reg | SUN4I_CTL_XCH, &priv->regs->ctl); >>>> >>>> /* Wait transfer to complete */ >>>> ret = wait_for_bit_le32(&priv->regs->ctl, SUN4I_CTL_XCH_MASK, >>>> false, SUN4I_SPI_TIMEOUT_US, false); >>>> if (ret) { >>>> printf("ERROR: sun4i_spi: Timeout transferring data\n"); >>>> sun4i_spi_set_cs(bus, slave_plat->cs, false); >>>> return ret; >>>> } >>>> >>>> /* Drain the RX FIFO */ >>>> if (!priv->rx_buf) { >>>> reg = readl(&priv->regs->fifo_sta); >>>> reg &= SUN4I_FIFO_STA_RF_CNT_MASK; >>>> cnt = reg >> SUN4I_FIFO_STA_RF_CNT_BITS; >>>> printf("rx fifo: before: %d, ", cnt); >>>> } >>>> >>>> sun4i_spi_drain_fifo(priv, nbytes); >>> So it's draining fifo without need to checking the available count >>> insun4i_spi_drain_fifo(), I mean the below code not require. >>> >>> /* See how much data is available */ >>> reg = readl(&priv->regs->fifo_sta); >>> reg &= SUN4I_FIFO_STA_RF_CNT_MASK; >>> cnt = reg >> SUN4I_FIFO_STA_RF_CNT_BITS; >>> >>> if (len > cnt) >>> len = cnt; >> Yes, I didn't made any modification to sun4i_spi_drain_fifo() function: > OK, thanks for the details and test. > > Please send the v2 with proper commit head it should be "spi: sun4i: ..." > Also I didn't find this patch on patchwork, don't know why? No idea. I can see it here: https://patchwork.ozlabs.org/patch/1008181/