From: trix@redhat.com To: noralf@tronnes.org, airlied@linux.ie, daniel@ffwll.ch Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Tom Rix <trix@redhat.com> Subject: [PATCH] drm/repaper: combine allocs in repaper_spi_transfer() Date: Sun, 13 Mar 2022 07:10:08 -0700 [thread overview] Message-ID: <20220313141008.1503638-1-trix@redhat.com> (raw) From: Tom Rix <trix@redhat.com> repaper_spi_transfer() allocates a single byte for the spi header and then another buffer for the payload. Combine the allocs into a single buffer with offsets. To simplify the offsets put the header after the payload. Signed-off-by: Tom Rix <trix@redhat.com> --- drivers/gpu/drm/tiny/repaper.c | 40 ++++++++++------------------------ 1 file changed, 12 insertions(+), 28 deletions(-) diff --git a/drivers/gpu/drm/tiny/repaper.c b/drivers/gpu/drm/tiny/repaper.c index 37b6bb90e46e1..22a6732f35a01 100644 --- a/drivers/gpu/drm/tiny/repaper.c +++ b/drivers/gpu/drm/tiny/repaper.c @@ -100,50 +100,34 @@ static inline struct repaper_epd *drm_to_epd(struct drm_device *drm) static int repaper_spi_transfer(struct spi_device *spi, u8 header, const void *tx, void *rx, size_t len) { - void *txbuf = NULL, *rxbuf = NULL; struct spi_transfer tr[2] = {}; - u8 *headerbuf; + u8 *buf; int ret; - headerbuf = kmalloc(1, GFP_KERNEL); - if (!headerbuf) + buf = kmalloc(1 + len, GFP_KERNEL); + if (!buf) return -ENOMEM; - headerbuf[0] = header; - tr[0].tx_buf = headerbuf; + buf[len] = header; + tr[0].tx_buf = &buf[len]; tr[0].len = 1; - /* Stack allocated tx? */ - if (tx && len <= 32) { - txbuf = kmemdup(tx, len, GFP_KERNEL); - if (!txbuf) { - ret = -ENOMEM; - goto out_free; - } + if (tx) { + memcpy(buf, tx, len); + tr[1].tx_buf = buf; } - if (rx) { - rxbuf = kmalloc(len, GFP_KERNEL); - if (!rxbuf) { - ret = -ENOMEM; - goto out_free; - } - } + if (rx) + tr[1].rx_buf = buf; - tr[1].tx_buf = txbuf ? txbuf : tx; - tr[1].rx_buf = rxbuf; tr[1].len = len; ndelay(80); ret = spi_sync_transfer(spi, tr, 2); if (rx && !ret) - memcpy(rx, rxbuf, len); - -out_free: - kfree(headerbuf); - kfree(txbuf); - kfree(rxbuf); + memcpy(rx, buf, len); + kfree(buf); return ret; } -- 2.26.3
WARNING: multiple messages have this Message-ID (diff)
From: trix@redhat.com To: noralf@tronnes.org, airlied@linux.ie, daniel@ffwll.ch Cc: Tom Rix <trix@redhat.com>, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org Subject: [PATCH] drm/repaper: combine allocs in repaper_spi_transfer() Date: Sun, 13 Mar 2022 07:10:08 -0700 [thread overview] Message-ID: <20220313141008.1503638-1-trix@redhat.com> (raw) From: Tom Rix <trix@redhat.com> repaper_spi_transfer() allocates a single byte for the spi header and then another buffer for the payload. Combine the allocs into a single buffer with offsets. To simplify the offsets put the header after the payload. Signed-off-by: Tom Rix <trix@redhat.com> --- drivers/gpu/drm/tiny/repaper.c | 40 ++++++++++------------------------ 1 file changed, 12 insertions(+), 28 deletions(-) diff --git a/drivers/gpu/drm/tiny/repaper.c b/drivers/gpu/drm/tiny/repaper.c index 37b6bb90e46e1..22a6732f35a01 100644 --- a/drivers/gpu/drm/tiny/repaper.c +++ b/drivers/gpu/drm/tiny/repaper.c @@ -100,50 +100,34 @@ static inline struct repaper_epd *drm_to_epd(struct drm_device *drm) static int repaper_spi_transfer(struct spi_device *spi, u8 header, const void *tx, void *rx, size_t len) { - void *txbuf = NULL, *rxbuf = NULL; struct spi_transfer tr[2] = {}; - u8 *headerbuf; + u8 *buf; int ret; - headerbuf = kmalloc(1, GFP_KERNEL); - if (!headerbuf) + buf = kmalloc(1 + len, GFP_KERNEL); + if (!buf) return -ENOMEM; - headerbuf[0] = header; - tr[0].tx_buf = headerbuf; + buf[len] = header; + tr[0].tx_buf = &buf[len]; tr[0].len = 1; - /* Stack allocated tx? */ - if (tx && len <= 32) { - txbuf = kmemdup(tx, len, GFP_KERNEL); - if (!txbuf) { - ret = -ENOMEM; - goto out_free; - } + if (tx) { + memcpy(buf, tx, len); + tr[1].tx_buf = buf; } - if (rx) { - rxbuf = kmalloc(len, GFP_KERNEL); - if (!rxbuf) { - ret = -ENOMEM; - goto out_free; - } - } + if (rx) + tr[1].rx_buf = buf; - tr[1].tx_buf = txbuf ? txbuf : tx; - tr[1].rx_buf = rxbuf; tr[1].len = len; ndelay(80); ret = spi_sync_transfer(spi, tr, 2); if (rx && !ret) - memcpy(rx, rxbuf, len); - -out_free: - kfree(headerbuf); - kfree(txbuf); - kfree(rxbuf); + memcpy(rx, buf, len); + kfree(buf); return ret; } -- 2.26.3
next reply other threads:[~2022-03-13 14:10 UTC|newest] Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-03-13 14:10 trix [this message] 2022-03-13 14:10 ` [PATCH] drm/repaper: combine allocs in repaper_spi_transfer() trix 2022-03-13 15:41 ` Noralf Trønnes 2022-03-13 15:41 ` Noralf Trønnes 2022-03-13 16:07 ` Tom Rix 2022-03-13 16:07 ` Tom Rix 2022-03-13 21:02 ` Noralf Trønnes 2022-03-13 21:02 ` Noralf Trønnes
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