linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Serge Semin <Sergey.Semin@baikalelectronics.ru>
To: Serge Semin <fancer.lancer@gmail.com>, Mark Brown <broonie@kernel.org>
Cc: Alexey Malahov <Alexey.Malahov@baikalelectronics.ru>,
	Ramil Zaripov <Ramil.Zaripov@baikalelectronics.ru>,
	Pavel Parkhomenko <Pavel.Parkhomenko@baikalelectronics.ru>,
	<linux-spi@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: [PATCH] spi: dw: Set transfer handler before unmasking the IRQs
Date: Tue, 17 Nov 2020 12:40:54 +0300	[thread overview]
Message-ID: <20201117094054.4696-1-Sergey.Semin@baikalelectronics.ru> (raw)

It turns out the IRQs most like can be unmasked before the controller is
enabled with no problematic consequences. The manual doesn't explicitly
state that, but the examples perform the controller initialization
procedure in that order. So the commit da8f58909e7e ("spi: dw: Unmask IRQs
after enabling the chip") hasn't been that required as I thought. But
anyway setting the IRQs up after the chip enabling still worth adding
since it has simplified the code a bit. The problem is that it has
introduced a potential bug. The transfer handler pointer is now
initialized after the IRQs are enabled. That may and eventually will cause
an invalid or uninitialized callback invocation. Fix that just by
performing the callback initialization before the IRQ unmask procedure.

Fixes: da8f58909e7e ("spi: dw: Unmask IRQs after enabling the chip")
Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru>
---
 drivers/spi/spi-dw-core.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-dw-core.c b/drivers/spi/spi-dw-core.c
index 2e50cc0a9291..0b2236ade412 100644
--- a/drivers/spi/spi-dw-core.c
+++ b/drivers/spi/spi-dw-core.c
@@ -357,11 +357,11 @@ static void dw_spi_irq_setup(struct dw_spi *dws)
 	dw_writel(dws, DW_SPI_TXFTLR, level);
 	dw_writel(dws, DW_SPI_RXFTLR, level - 1);
 
+	dws->transfer_handler = dw_spi_transfer_handler;
+
 	imask = SPI_INT_TXEI | SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI |
 		SPI_INT_RXFI;
 	spi_umask_intr(dws, imask);
-
-	dws->transfer_handler = dw_spi_transfer_handler;
 }
 
 /*
-- 
2.29.2


             reply	other threads:[~2020-11-17  9:41 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-17  9:40 Serge Semin [this message]
2020-11-17 22:38 ` [PATCH] spi: dw: Set transfer handler before unmasking the IRQs Mark Brown

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=20201117094054.4696-1-Sergey.Semin@baikalelectronics.ru \
    --to=sergey.semin@baikalelectronics.ru \
    --cc=Alexey.Malahov@baikalelectronics.ru \
    --cc=Pavel.Parkhomenko@baikalelectronics.ru \
    --cc=Ramil.Zaripov@baikalelectronics.ru \
    --cc=broonie@kernel.org \
    --cc=fancer.lancer@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-spi@vger.kernel.org \
    /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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).