From: Charles Keepax <ckeepax@opensource.cirrus.com>
To: "Goud, Srinivas" <srinivas.goud@amd.com>
Cc: "broonie@kernel.org" <broonie@kernel.org>,
"linux-spi@vger.kernel.org" <linux-spi@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"patches@opensource.cirrus.com" <patches@opensource.cirrus.com>
Subject: Re: [PATCH 1/2] spi: spi-cadence: Avoid read of RX FIFO before its ready
Date: Mon, 15 May 2023 12:54:58 +0000 [thread overview]
Message-ID: <20230515125458.GT68926@ediswmail.ad.cirrus.com> (raw)
In-Reply-To: <PH8PR12MB6675F6CC30254C5EED898FD5E1789@PH8PR12MB6675.namprd12.prod.outlook.com>
On Mon, May 15, 2023 at 12:04:38PM +0000, Goud, Srinivas wrote:
> >-----Original Message-----
> >From: Charles Keepax <ckeepax@opensource.cirrus.com>
> >Sent: Tuesday, May 9, 2023 10:12 PM
> >To: broonie@kernel.org
> >Cc: Goud, Srinivas <srinivas.goud@amd.com>; linux-spi@vger.kernel.org;
> >linux-kernel@vger.kernel.org; patches@opensource.cirrus.com
> >Subject: [PATCH 1/2] spi: spi-cadence: Avoid read of RX FIFO before its ready
> >- while (trans_cnt) {
> >- cdns_spi_read_rx_fifo(xspi, 1);
> >-
> >- if (xspi->tx_bytes) {
> >- if (xspi->txbuf)
> >- cdns_spi_write(xspi, CDNS_SPI_TXD,
> >- *xspi->txbuf++);
> >- else
> >- cdns_spi_write(xspi, CDNS_SPI_TXD,
> >0);
> >- xspi->tx_bytes--;
> >- }
> >- trans_cnt--;
> >- }
> >- if (!xspi->tx_bytes) {
> >- /* Fixed delay due to controller limitation with
> >- * RX_NEMPTY incorrect status
> >- * Xilinx AR:65885 contains more details
> >- */
> >- udelay(10);
> >- cdns_spi_read_rx_fifo(xspi, xspi->rx_bytes);
> >+ cdns_spi_read_rx_fifo(xspi, trans_cnt);
> Cadence SPI configured in Slave mode, when threshold is half of FIFO depth cdns_spi_read_rx_fifo() function continuously in read mode,
> due to this we see incorrect data received on the Master side as Slave is failed to update the TX FIFO on time.
Apologies I am having a little trouble following this are you
saying this part of the patch cases issues for you running in
slave mode?
Thanks,
Charles
next prev parent reply other threads:[~2023-05-15 12:55 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-09 16:41 [PATCH 1/2] spi: spi-cadence: Avoid read of RX FIFO before its ready Charles Keepax
2023-05-09 16:41 ` [PATCH 2/2] spi: spi-cadence: Only overlap FIFO transactions in slave mode Charles Keepax
2023-05-15 11:09 ` [PATCH 1/2] spi: spi-cadence: Avoid read of RX FIFO before its ready Mark Brown
2023-05-15 12:04 ` Goud, Srinivas
2023-05-15 12:54 ` Charles Keepax [this message]
2023-05-17 5:24 ` Goud, Srinivas
2023-05-17 10:46 ` Charles Keepax
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230515125458.GT68926@ediswmail.ad.cirrus.com \
--to=ckeepax@opensource.cirrus.com \
--cc=broonie@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-spi@vger.kernel.org \
--cc=patches@opensource.cirrus.com \
--cc=srinivas.goud@amd.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.