From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jagan Teki Date: Thu, 20 Dec 2018 18:14:22 +0530 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 Thu, Dec 20, 2018 at 6:12 PM Stefan Mavrodiev wrote: > > > 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/ OK, got it. I will format the commit and apply if are OK?